Loading...

Table of Content

    16 November 2019, Volume 52 Issue 22
    MOLECULAR GENETICS
    Progresses in Stress Tolerance and Field Cultivation Studies of Orphan Cereals in China
    DIAO XianMin
    Scientia Agricultura Sinica. 2019, 52(22):  3943-3949.  doi:10.3864/j.issn.0578-1752.2019.22.001
    Abstract ( 640 )   HTML ( 123 )   PDF (378KB) ( 954 )   Save
    References | Related Articles | Metrics

    Small cereal crops, including foxtail millet (Setaria italica), sorghum (Sorghum bicolor) and broomcorn millet (Panicum miliaceum), are important in northern China’s arid and semi-arid dry land agriculture, which are main components for a diversified food system and considered as traditional healthy food. Because they are mainly cultivated in dry land and salinity soils, natural and human selection had made those crops with super capability for drought and salt tolerant. This issue of Scientia Agricultura Sinica published 20 papers focus on drought tolerance, salinity tolerance, disease resistance and cultivation of those orphan crops in China. Nearly all these papers were conducted by the scientific researcher of the Chinese Agricultural Research System, Millet and Sorghum Section. This is a brief introduction of these 20 papers, and some comparisons between conclusions of those researches with the known published ones are also included. Foxtail millet, sorghum and broomcorn millet are considered as models for drought and salinity study in the grasses family, the papers published here will push the progress of this system.

    Identification NADP-ME Gene of Foxtail Millet and Its Response to Stress
    ZHAO JinFeng,DU YanWei,WANG GaoHong,LI YanFang,ZHAO GenYou,WANG ZhenHua,CHENG Kai,WANG YuWen,YU AiLi
    Scientia Agricultura Sinica. 2019, 52(22):  3950-3963.  doi:10.3864/j.issn.0578-1752.2019.22.002
    Abstract ( 401 )   HTML ( 38 )   PDF (6457KB) ( 433 )   Save
    Figures and Tables | References | Related Articles | Metrics

    【Objective】 The objectives of this study are to identify the NADP-ME family genes (SiNADP-MEs) from foxtail millet (Setaria italica) genome, study the response of different members to abiotic stress, and to lay a theoretical foundation for revealing the role of SiNADP-ME genes in stress signal pathway of foxtail millet. 【Method】 The members of NADP-ME family in the foxtail millet genome were identified by bioinformatics methods. The protein and gene sequence of identified members were analyzed using software such as GSDS2.0, plantCARE, Clustalx, MEGA6.0 and the website ExPASy. Real-time quantitative PCR (qRT-PCR) was used to detect the expression levels of SiNADP-ME genes under different stresses at seedling stage, under drought and different light intensities stress at different growth stages. 【Result】 The NADP-ME family of foxtail millet consists of seven members, which were unevenly distributed on chromosomes 2, 3, 5, and 7 of foxtail millet. Conservative functional domain analysis revealed that all seven genes contain the conserved characteristic domains of NADP-ME. Amino acid sequence alignment revealed that the sequences were very conserved and the similarity was very high among the members. The sequence identity of 7 SiNADP-ME members was 77.30%, while the identity of NADP-MEs in different species was 56.52%. Sequence analysis showed that the sequences of SiNADP-ME1, 4, 5, and 6 were longer, encoding 576, 639, 652, and 636 amino acids residues respectively, while the sequences of SiNADP-ME2, 3, and 7 were shorter, encoding 213, 265 amino acids residues respectively. Gene structure analysis showed that SiNADP-ME1 has two alternative transcript, SiNADP-ME5 has three alternative transcript, and other genes have no alternative transcript. SiNADP-ME1, 2, 3 and 7 contain fewer introns, while SiNADP-ME4, 5 and 6 contain more introns. The prediction of protein parameters showed that the molecular weight span among members is large, ranging from 161.94 to 725.43 kD, the isoelectric point from 5.32 to 8.05, the instability index from 23.01 to 45.01, the aliphatic index from 89.19 to 107.77, and the grand average of hydropathicity from -0.218 to 0.004. Subcellular localization predictions show that SiNADP-ME members are mainly localized in chloroplasts, mitochondrial and cytoplasmic. Cis-elements analysis revealed that hormonal, stress, light, and other growth-related cis-elements are present in the promoter region of the SiNADP-ME members. Cluster analysis revealed that SiNADP-ME genes were present before the isolation of monocotyledonous and dicotyledonous plants. The homologous pairs of different species present in the phylogenetic tree revealed that they may evolve from a common ancestor, suggesting that they may have similar functions in certain signaling pathways. Stress expression analysis of seedling stage showed that the expression levels of all the SiNADP-ME family genes were significantly induced under the four stresses applied in this paper. The highest relative expression levels of SiNADP-ME1 under ABA, low temperature and NaCl treatment were 460.53, 411.50 and 15.24 folds than that of the control respectively, while the highest relative expression levels of SiNADP-ME6 under ABA, low temperature, PEG and NaCl treatment were 211.13, 15.21, 772.41 and 643.99 folds than that of the control respectively. Further analysis showed that the expression levels of SiNADP-ME1 and SiNADP-ME6 were up-regulated under drought stress at jointing, heading and filling stage.【Conclusion】 Seven members of NADP-ME gene family were identified from foxtail millet genome. All SiNADP-ME genes contain the typical characteristic domains of the NADP-ME, and their sequences are very conserved. All of the SiNADP-ME genes are involved in plant abiotic stress response, especially SiNADP-ME1 and SiNADP-ME6 may play an important role in response to abiotic stress.

    Transcriptomics Analysis of NaCl Response in Foxtail Millet (Setaria italica L.) Seeds at Germination Stage
    PAN JiaoWen, LI Zhen, WANG QingGuo, GUAN YanAn, LI XiaoBo, DAI ShaoJun, DING GuoHua, LIU Wei
    Scientia Agricultura Sinica. 2019, 52(22):  3964-3975.  doi:10.3864/j.issn.0578-1752.2019.22.003
    Abstract ( 585 )   HTML ( 53 )   PDF (2396KB) ( 555 )   Save
    Figures and Tables | References | Related Articles | Metrics

    【Objective】 Foxtail millet (Setaria italica L.) remarkably adapts to adverse ecologies, including drought, barren regions and high soil salinity. These characteristics promote it as a very promising model crop for exploring basic biology processes of plants. Unveil of mechanisms of foxtail millet under salinity is of immense significance. 【Method】 In this research, 14 millet varieties at germination stage were used for resistance screening under 150 mmol·L -1 NaCl. The germination rate, root and bud length of each variety were measured after been treated for 7 d, and the salt tolerance variety Yugu 2 and salt susceptible variety An 04 were obtained. These two varieties before and after salt treatment were used for transcriptomes analysis by RNA-seq sequencing. The functional and pathway enrichments of differentially expressed genes (DEGs) were also performed by GO and KEGG analysis. Fifteen DEGs were randomly selected for further qRT-PCR analysis to verify the RNA-seq data.【Result】 Totally 2 786 and 4 413 DEGs were identified in Yugu 2 and An 04, and there were 1 470 and 3 826 DEGs within each cultivar before and after salt treatment, respectively. GO and KEGG enrichment analysis suggested that DEGs were mainly clustered into signaling, antioxidant system, organic acid biosynthesis and transport, and secondary metabolism, and the DEGs participated in response to stress, ion transmembrane transport, redox homeostasis, secondary metabolism, organic acid, polyamine and phenylpropanoid biosynthetic process. The qRT-PCR results showed high correlation coefficient of 0.8817 with the data of RNA-seq. Especially the genes such as cation transporter (HKT8), peroxidase (POD), flavanone 3-dioxygenase (FL3H) and MYB transcription factors, which displayed higher vary degrees in Yugu2 under salinity may play key roles in salt response process of foxtail millet. 【Conclusion】There was difference in the response degree of salt tolerance variety and salt sensitive variety of millet under salinity. Moreover, the resistance trait formation and function to salt was mainly depends on the response degree instead of the number of DEGs under stress.

    Response of Receptor-Like Protein Kinase Gene SiRLK35 of Foxtail Millet to Salt in Heterologous Transgenic Rice
    LI XiaoBo,LI Zhen,DAI ShaoJun,PAN JiaoWen,WANG QingGuo,GUAN YanAn,DING GuoHua,LIU Wei
    Scientia Agricultura Sinica. 2019, 52(22):  3976-3986.  doi:10.3864/j.issn.0578-1752.2019.22.004
    Abstract ( 365 )   HTML ( 27 )   PDF (1208KB) ( 272 )   Save
    Figures and Tables | References | Related Articles | Metrics

    【Objective】Salt stress affects the crop yield and quality, while the crop salt tolerance is regulated by specific genes. Using heterogeneous over-expressed rice lines (OE-1, OE-2, and OE-3) of foxtail millet receptor-like protein kinase gene SiRLK35, the possible mechanisms of SiRLK35 under salinity will be dissected on phenotypic, physiological and molecular levels. 【Method】 The expressions of SiRLK35 in OE-1, OE-2, and OE-3 were analyzed by qRT-PCR. The phenotypes of three-leaf stage seedlings treated with 0, 150 and 200 mmol·L -1 NaCl were observed, and the lengths of seedlings and roots were measured after treated with 150 mmol·L -1 NaCl for 3 days. The dry weights, death rate and dead leaf rate of four-leaf stage seedlings that treated with 150 mmol·L -1 NaCl for 14 days were also measured. OE-1with the highest SiRLK35 expression was further used for DAB and NBT dyeing analysis. The activities of partial antioxidases, and expression patterns of marker genes were detected. 【Result】 There was the highest SiRLK35 expression level in OE-1. The growth of control and OE seedlings were all inhibited under 150 mmol·L -1 NaCl. The decreased levels of dry weight, the death rate and dead leaf rate of OE rice were all lower than those of the control, together with the less accumulation of O 2- and H2O2, and the higher activities of antioxidases under salinity. Partial of salt responsive genes were up-regulated in SiRLK35 OE lines, especially the OsLEA3 was induced about 1.9 times higher after treated with NaCl for 24 h. 【Conclusion】 SiRLK35 OE rice lines have tolerance under salinity, and the gene SiRLK35 of foxtail millet could participate in salt response by regulation the activities of antioxidases and related signal pathways.

    Transcriptome Analysis and Gene Mining of Salt Tolerance in Sorghum Seedlings (Sorghum bicolor L. Moench)
    DONG Ming, KUERBAN Zaituniguli, Lü Peng, DU RuiHeng, YE Kai, HOU ShengLin, LIU GuoQing
    Scientia Agricultura Sinica. 2019, 52(22):  3987-4001.  doi:10.3864/j.issn.0578-1752.2019.22.005
    Abstract ( 375 )   HTML ( 36 )   PDF (2300KB) ( 384 )   Save
    Figures and Tables | References | Related Articles | Metrics

    【Object】The primary aim of this study was to identify salt tolerance genes and explore the tolerance response mechanism under salt stress in sorghum, which may provide a theoretical basis for sorghum salt tolerance breeding. 【Method】Two sorghum varieties, L-Tian, salt-sensitive and Shihong 137, salt-tolerant were employed as plant materials. The sorghum seedlings were treated with 2% NaCl solution at three-leaf and one heart stage. Three treatments including 0 h (CK), 1 h and 24 h were conducted. The plant height, root length, dry matter weight, Na + content and relative content of chlorophyll (SPAD value) were determined, and the transcriptome sequencing was performed on Illumina HiSeq 2000 platform. The FPKM method was employed to calculate the gene expression level. Both the differential expression fold (Fold Change) ≥ 2 and FDR<0.001 were used as screening criteria to detect the differentially expressed genes. The Gene Ontology and KEGG Pathway databases were used to analyze the differentially expressed genes involved in salt stress at different time points. 【Result】Salt stress had no significant effect on plant height, root length and dry matter weight of sorghum, but had significant effect on Na + content and SPAD value. The plant height, root length, Na + content and SPAD value of Shihong 137 were higher than those of L-tian. Totally 26628 known genes and 866 new genes have been identified from RNA-seq, of which, the number of differentially expressed genes from Shihong 137 is higher than that from L-tian. 375, 4206 and 3750 differentially expressed genes in 0 h VS 1 h, 0 h VS 24 h and 1 h VS 24 h groups had been identified from Shihong 137 respectively. The number of differentially expressed genes of 0 h VS 1 h, 0 h VS 24 h, and 1 h VS 24 h of L-tian was 167, 2534 and 1612, respectively. GO and KEGG analysis revealed that plant hormones such as abscisic acid, auxin, cytokinin, gibberellin and ethylene were involved in the salt tolerance of sorghum at an early stage of salt stress (1h), while Lhca, Lhcb, phosphoenolpyruvate carboxylase, and ribulose phosphate kinase were involved in the salt tolerance at a late stage of salt stress (24 h). The difference in salt tolerance between Shihong 137 and L-tian was mainly caused by the flavonoid biosynthetic metabolic pathway. 【Conclusion】The sorghum response to salt stress is a complex biological process that relies on the balanced expression of multiple genes in complex networks. Under salt stress, sorghum response to environmental stimuli was controlled by both hormonal signal transduction and photosynthesis. The flavonoid biosynthesis pathway played an important role in salt-tolerant varieties.

    Comparative Transcriptome Analysis of Different Salt Tolerance Sorghum (Sorghum bicolor L. Moench) Under Salt Stress
    ZHANG Fei,WANG YanQiu,ZHU Kai,ZHANG ZhiPeng,ZHU ZhenXing,LU Feng,ZOU JianQiu
    Scientia Agricultura Sinica. 2019, 52(22):  4002-4015.  doi:10.3864/j.issn.0578-1752.2019.22.006
    Abstract ( 448 )   HTML ( 32 )   PDF (2192KB) ( 434 )   Save
    Figures and Tables | References | Related Articles | Metrics

    【Objective】Soil salinization is one of the important abiotic stress factors that restricts crop production. Understanding the salt-tolerant mechanism of sorghum may provide a novel avenue to utilize saline soil for sorghum production. The objective of this study was to explore gene regulation mechanisms and metabolic pathways that related to salt tolerance of sorghum by transcriptome sequencing. 【Method】 The salt-tolerant genotype Bayeqi and salt-sensitive genotype PL212 were planted in plastic pots. At five-leaf stage (20 days after sowing), plants were treated with 180 mmol L -1 NaCl. Forty-eight hours after treatment, leaves treated by NaCl and unstressed control were sampled and were used for RNA extraction and transcriptome sequencing. Sequencing results were verified by qRT-PCR. 【Result】 Results showed that a total of 1 338 deferentially expressed genes, including 819 up-regulated and 519 down-regulated genes were detected. Cluster analysis revealed that in response to salt stress, five dependent oxygenase superfamily proteins, four cysteine-rich RLKs, three Glutathione S-transferase and three heavy metal transport/detoxification superfamily protein-related genes were significant up-regulated and/or down-regulated, and one K + ion transporter gene was also found to play an important role in salt-tolerance regulation. GO analysis found that 4 528 valid GO annotation entries were obtained from 15 418 genes, and salt-tolerant and salt-sensitive materials showed significant difference in biological processes, cellular components and molecular functions under salt stress treatment. The salt-tolerant materials exhibited obviously higher metabolic processes and cellular processes than salt-sensitive materials. Compared with salt-sensitive materials, multiple biological processes and localization processes were increased in salt-tolerant genotype, which might be the reasons of salt-tolerance. KEGG analysis showed that the salt-tolerant and salt-sensitive materials had more differential gene expression in phenylpropanoid biosynthesis, phenylalanine metabolism and flavonoid biosynthesis under control and salt stress conditions, which may be an important reason for the weak salt tolerance of sensitive materials. 【Conclusion】 The expression of salt-tolerant genes in sorghum is involved in many aspects of biological processes, cellular components and molecular functions. The gene expression in multiple processes and localization processes contributes to the salt tolerance, while excessive gene expression in phenylpropanoid biosynthesis, phenylalanine metabolism, and flavonoid biosynthesis likely contributes to the damage under salt stress.

    Identification and Expression Analysis of MYB Transcription Factors Related to Rust Resistance in Foxtail Millet
    BAI Hui, SONG ZhenJun, WANG YongFang, QUAN JianZhang, MA JiFang, LIU Lei, LI ZhiYong, DONG ZhiPing
    Scientia Agricultura Sinica. 2019, 52(22):  4016-4026.  doi:10.3864/j.issn.0578-1752.2019.22.007
    Abstract ( 290 )   HTML ( 29 )   PDF (1303KB) ( 290 )   Save
    Figures and Tables | References | Related Articles | Metrics

    【Objective】 Millet rust is one of the important factors affecting the yield and quality of foxtail millet. Identification of MYB transcription factors related to rust resistance in foxtail millet lays a foundation for the study of the mechanism of rust resistance in foxtail millet. 【Method】 In this study, we used real-time PCR to detect the expression patterns of 9 MYB transcription factors (1) in roots, stems, leaves and panicles at booting stage; (2) during 120 hours post-inoculated with Uromyces setariae-italicae urediniospores in resistance (R) and susceptible (S) reactions; (3) during 24 hours after treatment with salicylic acid (SA) and methyl jasmonate (MeJA) in foxtail millet. Then their expression patterns in four reactions of R, S, SA and MeJA were compared, and the resistance-related MYB transcription factors were selected for detection of transactivation activity and subcellular localization. 【Result】 The highest expression of SiMYB100 was in leaves, and the highest expression of the other eight genes, especially SiMYB074, was in roots. The expression of five genes was correlated with disease resistance. SiMYB074 and SiMYB202 were induced by rust fungus infection and their expression levels at early stage of disease resistance were significantly higher than that in the susceptible reaction. The expression of SiMYB041 and SiMYB177 was down-regulated in the early stage of resistance reaction and increased to pre-inoculation level in the later stage, while their expression remained low in susceptible reaction. SiMYB100 showed opposite expression pattern in resistance and susceptible responses. In response to exogenous SA and MeJA, the expression of SiMYBs gene changed in varying degrees. The expression patterns of four genes (SiMYB074, SiMYB100, SiMYB174 and SiMYB202) in the R, SA and MeJA reactions were identical, but different from the S reaction. Five resistance-related SiMYBs genes have the transactivation activity and their encoding proteins are located in the nucleus. 【Conclusion】 The expression of five genes, SiMYB041, SiMYB074, SiMYB100, SiMYB177 and SiMYB202, was identified to be associated with resistance to rust disease in foxtail millet. SiMYB074 and SiMYB100 play certain roles in the growth and disease resistance of foxtail millet. Four genes, SiMYB074, SiMYB100, SiMYB174 and SiMYB202, may participate in early disease resistance of foxtail millet through SA and JA signaling pathways.

    GERMPLASM RESOURCES
    Screening for Germplasms Tolerant to Salt at Germination Stage and Response of Protective Enzymes to Salt Stress in Foxtail Millet
    QIN Ling, ZHANG YanTing, CHEN ErYing, YANG YanBing, LI FeiFei, GUAN YanAn
    Scientia Agricultura Sinica. 2019, 52(22):  4027-4038.  doi:10.3864/j.issn.0578-1752.2019.22.008
    Abstract ( 399 )   HTML ( 20 )   PDF (1691KB) ( 320 )   Save
    Figures and Tables | References | Related Articles | Metrics

    【Objective】The purpose of this study was to select germplasms tolerant to salt at germination stage, to establish an evaluation criterion for salt tolerance, and to investigate the effect of salt stress on protective enzyme system of different genotypes of foxtail millet at seedling stage. The results could propose an identification method and excellent genetic resources for research on salt-tolerant mechanisms of foxtail millet.【Method】54 foxtail millet varieties from different eco-regions were applied as experimental materials. Salt stress was implemented by adding 1.5% NaCl solution, and distilled water was used as the control. A petri dish based germination method was used to assess the salt tolerance of foxtail millet varieties in artificial climate incubator. Six salt-tolerant indexes were investigated in each treatment, including relative germination potential, relative germination rate, relative coleoptile length, relative radical root length, relative radical root / coleoptiles, and relative salt damage rate. A comprehensive analysis of the salt tolerance of different varieties was conducted via correlation analysis, principal component analysis and clustering analysis. Furthermore, pot experiment was conducted to cultivate selected varieties with different salt tolerance under both salt stress and normal conditions, and superoxide dismutase (SOD) activity, peroxidase (POD) activity, and catalase (CAT) activity in shoot were analyzed. And then the differences of physiological responses between those genotypes under salt stress were analyzed.【Result】Under salt stress of 1.5% NaCl , a significant positive correlation was detected between relative germination potential and relative germination(r=0.51, P<0.01) and relative coleoptile length (r=0.54, P<0.01). There was a significant positive correlation between relative coleoptile length and relative radical root length (r=0.64, P<0.01), while the relative salt damage rate showed a significant negative correlation with relative germination rate (r=-0.37, P<0.01) and relative coleoptile length (r=-0.51, P<0.01). Principal component analysis transformed the six single indexes in the salt-stressed germination stage of foxtail millet to three independent comprehensive indexes. Subordinate function analysis was conducted to obtain the comprehensive assessment value (D-value) of salt tolerance of different varieties at germination stage. 54 foxtail millet varieties were classified into five salt tolerant types based on clustering analysis, including extremely salt sensitive, salt sensitive, moderate salt tolerance, salt tolerance and high salt tolerance. The varieties with high salt tolerance were Yangu 13, Longgu 3 from spring sowing region of northwest China, and Jigu 16, Ai88 from summer sowing region of north China. The activities of SOD, POD, and CAT were increased and then decreased under salt stress condition. SOD, POD, and CAT in shoot increased in response to salt stress, and the activity of those enzymes in Jigu 16 was significantly higher than that in Lugu 1.【Conclusion】Remarkable variations in salt tolerance were detected among the 54 genotypes of foxtail millet. The systematical and clear results can be obtained by membership function analysis, and the salt tolerance of foxtail millet can be evaluated objectively and comprehensively. The leaf protective enzymes are important for the adaptability of foxtail millet to salt stress in seedling stage.

    Evaluation of Identification and Classification Index for Drought Resistance at Middle and Late Growth Stage in Grain Sorghum Germplasms
    WANG YuBin, PING JunAi, NIU Hao, CHU JianQiang, DU ZhiHong, Lü Xin, LI HuiMing, ZHANG FuYao
    Scientia Agricultura Sinica. 2019, 52(22):  4039-4049.  doi:10.3864/j.issn.0578-1752.2019.22.009
    Abstract ( 305 )   HTML ( 22 )   PDF (5908KB) ( 318 )   Save
    Figures and Tables | References | Related Articles | Metrics

    【Objective】 Sorghum is the fifth largest cereal crop in the world, which has a variety of usages. Compared with other crops, sorghum has a strong drought resistance, drought has become one of the main restricting factors in sorghum (especially grain sorghum) production, with the intensification of the global drought. Through drought resistance identification and classification index evaluation of grain sorghum materials were carried out in order to lay foundations for future studies on molecular mechanism of and breeding for drought resistance in sorghum. 【Method】 With 165 grain sorghum accessions as the experimental materials, drought resistance experiments with two treatments, drought (DS) and normal irrigation (NI), were carried out in the fields in Shanxi and Hainan provinces. Eight morphological traits, including plant height, panicle length, stem diameter, leaf greenness, lodging rate, 1000-grain weight, grain size and yield, were investigated. Cluster analysis was carried out by using three methods: Comprehensive Drought Tolerance Coefficient (CDTC), Drought Resistance Index(DI) and membership function(D).【Result】 Under drought stress, all 8 morphological indexes of grain sorghum decreased. Except that leaf greenness was not correlated with plant height and grain size, and lodging resistance was not correlated with panicle length and grain size, all the other indicators were correlated to some extent. Five high-resistant accessions (L013, SX44B, sx18-25, sx18-87 and L405) and 4 sensitive accessions (sx18-46, sx18-82, sx18-96 and sx18-73) were selected according to the three comprehensive drought resistance evaluation methods; According to the relative value and variation coefficient of morphological indicators, the experiments in both places showed that the stay-green, yield, grain size and lodging resistance were sensitive to drought, and there was overlapped information among the four indicators. According to the principal component analysis, yield, plant height and grain size were the main factors determining the first principal component, and the contribution rate was 31.841%; The greenness of the leaves and thousand-grain weight were the main factors determining the second principal component, and the contribution rate was 20.441%; Stem thickness were the main factors determining the third principal component, the contribution rate was 13.557%; the main factors determining the lodging resistance of the fourth principal component, the contribution rate was 11.428% ; The fifth principal component was spike length, the contribution rate was 9.461%. 【Conclusion】 It was found that drought stress at the middle and late growth stages had significant effects on the main morphological indicators of grain sorghum. There existed significant difference among accessions in drought resistance. Combined with three comprehensive evaluation methods of drought resistance, the drought resistance of sorghum accessions could be evaluated more accurately. Two traits stay green and yield could can be used as main morphological indicators to evaluate drought resistance of sorghum after flowering.

    Variation and Comprehensive Evaluation of Salt and Alkali Tolerance of Different Foxtail Millet Cultivars Under Production Conditions
    CHEN ErYing, QIN Ling, YANG YanBing, LI FeiFei, WANG RunFeng, ZHANG HuaWen, WANG HaiLian, LIU Bin, KONG QingHua, GUAN YanAn
    Scientia Agricultura Sinica. 2019, 52(22):  4050-4065.  doi:10.3864/j.issn.0578-1752.2019.22.010
    Abstract ( 255 )   HTML ( 20 )   PDF (927KB) ( 273 )   Save
    Figures and Tables | References | Related Articles | Metrics

    【Objective】The objective of the experiment was to identify variation of salt and alkali tolerance of different foxtail millet cultivars under saline-alkali soil and normal soil, and to develop identification method and index. 【Method】In this study, 8 newly developed elite foxtail millet cultivars in summer sowing region were used to explore the differences of salt and alkali tolerance among cultivars on saline-alkali soil and normal soil.【Result】The results showed that there was significant yield differences among cultivars at saline-alkali and control conditions, and the variable coefficients were 13.0% and 39.1%, respectively. Yields of 8 foxtail millet cultivars were reduced in different degree in saline-alkali soil compared with control. The range of yield salt injury rate among cultivars was 20.7%-63.4% and variable coefficient was 48.4%. There existed reduction in weight per panicle, grain weight per panicle, thousand seed weight, plant height, SPAD, shoot biomass and yield index of all cultivars in saline-alkali soil compared with control. Assimilate translocation amount pre-anthesis (ATAPA) was increased by 34.4% and accumulated assimilate amount post-anthesis (AAAPA) was reduced by 42.7% in saline-alkali soil compared with control. There had significantly positive correlation between salt injury rate of yield and contribution rate of accumulated assimilate post-anthesis to grain (CRAAPA) (R=0.859), and had significantly negative correlation between salt injury rate of yield and weight per panicle (R=0.859), grain weight per panicle (R=0.859), shoot biomass (R=-0.895), ATAPA (R=-0.935), assimilate translocation rate pre-anthesis (ATRPA) (R=-0.880), contribution rate of translocated assimilate pre-anthesis to grain (CRTAPA) (R=-0.859), AAAPA (R=-0.909) and shoot water content at anthesis (R=-0.834). Weight per panicle, grain weight per panicle, shoot biomass and shoot water content were screened as salt and alkali tolerant indexes from principal component analysis, Jigu21 and Jigu22 were screened as high salt and alkali tolerant cultivars from principal component analysis and membership function.【Conclusion】8 foxtail millet cultivars had different salt and alkali tolerance in saline-alkali soil, and Jigu22 and Jigu21 were selected as the strong salt and alkali tolerant cultivars. Weight per panicle, grain weight per panicle, shoot biomass and shoot water content at anthesis were screened as salt and alkali tolerance indexes. ATAPA was increased and AAAPA was reduced in saline-alkali soil compared with control, and salt injury rate of yield negatively correlated with ATAPA and shoot water content at anthesis, which showed that improving shoot water content at anthesis and the contribution rate of translocated assimilate pre-anthesis to yield were important approaches to increase foxtail millet grain yield on saline-alkali soil.

    Salt-Tolerance Evaluation and Physiological Response of Salt Stress of Broomcorn Millet (Panicum miliaceum L.)
    YUAN YuHao, YANG QingHua, DANG Ke, YANG Pu, GAO JinFeng, GAO XiaoLi, WANG PengKe, LU Ping, LIU MinXuan, FENG BaiLi
    Scientia Agricultura Sinica. 2019, 52(22):  4066-4078.  doi:10.3864/j.issn.0578-1752.2019.22.011
    Abstract ( 402 )   HTML ( 35 )   PDF (5899KB) ( 296 )   Save
    Figures and Tables | References | Related Articles | Metrics

    【Objective】 To evaluate the tolerance of broomcorn millet cultivars to salt stress, explore the physiological responses of different salt-tolerant broomcorn millet to salt stress, and establish the salt tolerance identification index system of broomcorn millet, the salt tolerance of broomcorn millet was studied. 【Method】 The growth parameters of 100 genotypes of broomcorn millet at germination stage and the physiological parameters of different salt-tolerant broomcorn millet at seedling stage were measured under salt stress. The tolerance of each variety to salt stress was evaluated by correlation analysis, principal component analysis, cluster analysis and physiological responses to salt stress. 【Result】 the results showed that the measured values of each shoot in the germination stage under 1% NaCl solution stress were lower than that of the control. Correlation analysis showed that there was a significant correlation in the different germination indexes, and there was a significant negative correlation with the relative salt damage rate. The principal component analysis results showed root fresh weight, germination index and germination rate were the larger load in germination factors and these indexes were considered as the main indexes to identify salt tolerance of broomcorn millet germination. The 100 broomcorn millet cultivars were sorted four groups according to the cluster analysis. The cluster analysis results showed eleven cultivars such as Yixuandahongmi, Wujushu, Baishu etc. were classified into salt-tolerant cultivar group, four cultivars including Humengheinianmi, Xiaoheishu, Linheshuanglishu, and Shaan78 were classified into salt sensitive group. There were great differences between salt tolerant cultivars and salt sensitive cultivars in morphological structure and physiological indexes. The scanning electron microscope results showed salt bladders appeared on the surface of salt-tolerant cultivars, the stomatal aperture size was barely changed. The salt-sensitive cultivar showed the stomata were closed in salt-sensitive broomcorn millet cultivar, and the surface of the leaf become rough, and the guard cells death occurred. With the increase of treatment time, the salt tolerant cultivar chloroplast changed from ellipsoid to spherical and starch granules increase, membrane disrupted, grana lamella arranged loosely, the thylakoids swollen and even disintegrate. With the days of salt stress increasing, the relative conductivity were increased. However, the relative conductivity in salt-tolerant broomcorn millet cultivar were lower than salt-sensitive broomcorn millet cultivar. The decreasing of Fv/Fm、Y(Ⅱ) and NPQ in salt-tolerant broomcorn millet cultivar were less than salt-sensitive broomcorn millet cultivar. 【Conclusion】 1% NaCl solution could be used as the suitable concentration of salt tolerance in broomcorn millet. The results showed that salt tolerance evaluation of broomcorn millet was affected with multiple indexes, and root fresh weight, germination index and germination rate could be used as the evaluation indexes of salt tolerance in germination stage. Stomatal state and chloroplast structures could be used as the cytology indexes of salt tolerance evaluation. The relative conductivity and chlorophyll fluorescence coefficient could be used as the physiology indexes of salt tolerance evaluation.

    Evaluation of Sorghum Accessions Resistance Against Colletotrichum sublineolum and Relationship Between Severity and Yield Loss on Sorghum
    XU Jing,JIANG Yu,HU Lan,LIU KeJie,XU XiuDe
    Scientia Agricultura Sinica. 2019, 52(22):  4079-4087.  doi:10.3864/j.issn.0578-1752.2019.22.012
    Abstract ( 267 )   HTML ( 13 )   PDF (1353KB) ( 218 )   Save
    Figures and Tables | References | Related Articles | Metrics

    【Objective】Base on the new problems of sorghum anthracnose (Colletotrichum sublineolum) prevalent recent years in sorghum production, screening sorghum disease-resistant resources under artificial inoculation conditions was carried out with the purpose of use host resistance to control the disease. The results of this study were expected to provide scientific basis and guidance for sorghum anthracnose resistance breeding and yield loss assessment in the field. 【Method】 During the year of 2016 and 2017, 74 sorghum accessions from home and abroad were identified for disease resistance by artificial inoculation with pathogen isolate of C. sublineolum (SY-1). Twenty accessions with different rating scale were used as test materials to determine yield losses caused by anthracnose diseases under artificial inoculation. The relationship between rating scale (severity) of disease and the main yield traits of sorghum was clarified by using the method of correlation analysis. 【Result】 The results showed that there were 21 accessions rated as highly resistant (HR) and accounted for 28.38% of the total of 74 sorghum accessions, 12 accessions rated as resistant (R) and accounted for 16.22%, 26 accessions rated as moderate resistant (MR) and accounted for 35.14%, 8 accessions rated as susceptibility (S) and accounted for 10.81%, and 7 accessions rated as high susceptibility (HS) and accounted for 9.46% of the total accessions. The relationship between the severity of disease and yield loss was clarified. The results showed that 1000-grain weight and grain weight per panicle of sorghum are significantly affected by sorghum anthracnose. The reduction of grain weight per panicle between 1- 9 grade diseased plants was 0.37%-78.00%, and the reduction of 1000-grain weight was 0.03%-44.43%. Correlation analysis showed that both of grain weight per panicle and 1000-grain weight had an exponential relationship with the rating scale of disease. The reduction rate of grain weight per panicle and 1000-grain weight of sorghum rise significantly with the increase of rating scale of disease, and the rise of reduction rate of grain weight per panicle is more rapid than that of 1000-grain weight. There was a close relationship between the severity and symptoms of disease. Accessions rated as HR showed symptoms of red spots on inoculated leaves, but no acervuli in the lesions and R accessions showed small circular to oval spots and acervuli development. MR accessions showed symptoms of abundant circular to oval spots on inoculated leaves and black acervuli development and some lesions also appear on panicle-stalk. S accessions showed circular to oval and long strip spots on inoculated leaves with abundant black acervuli development. Lesions on panicle-stalk were visible and part of leaves wilt and some diseased plants were died. On the HS accessions lesions join to cover a large proportion of the leaf and panicle-stalk surface with abundant black acervuli. Most leaves of diseased plants wilt and the whole plants were near death. 【Conclusion】 In this study, 21 accessions with highly resistant (HR) were screened. Both of grain weight per panicle and 1000-grain weight had an exponential relationship with the rating scale of the disease, and with the increase of rating scale, the loss rate of grain weight per panicle and 1000-grain weight of sorghum were increased correspondingly. In addition, the disease symptoms of sorghum anthracnose were obviously different with disease rating scale.

    Population Structure and Association Analysis of Main Agronomic Traits of Shanxi Core Collection in Foxtail Millet
    WANG HaiGang,WEN QiFen,MU ZhiXin,QIAO ZhiJun
    Scientia Agricultura Sinica. 2019, 52(22):  4088-4099.  doi:10.3864/j.issn.0578-1752.2019.22.013
    Abstract ( 348 )   HTML ( 16 )   PDF (2476KB) ( 341 )   Save
    Figures and Tables | References | Related Articles | Metrics

    【Objective】The objective of this study is to detect the SSR markers associated with agronomic trait and analyze genetic diversity and genetic structure of foxtail millet landrace in Shanxi province. The results will be helpful for hybridization combination of parent materials and molecular marker assisted breeding.【Method】96 SSR markers on 9 chromosomes were genome-wide screened for polymorphism in core collection of 595 accessions. PowerMarker 3.25 software was used to estimate the polymorphism information of population. Population structure was analyzed using STRUCTURE 2.3.4 software. Then the data were associated with 96 SSR markers by GLM (general linear model, Q) and MLM (mixed linear model, Q+K).【Result】Totally 828 alleles were found with 96 SSR markers and 8.6 alleles were revealed with each marker in average ranged from 2-26. The gene diversity was from 0.005 to 0.941, averagely 0.610. The polymorphism information content (PIC) value ranged from 0.005 to 0.938 with the mean of 0.577. Heterozygosity per locus on average was 0.016, ranging from 0 to 0.050. All the 595 accessions were divided into three subgroups by analysis of population genetic structure. There was linkage disequilibrium (LD) among linked loci and unlinked loci pairs, and 1 955 out of 4 560 loci pairs (42.9%) had significant LD (P < 0.01) with average D′ value of 0.23. A total of 12 locus found by GLM method significantly at the level of P<0.01 which explained 2.34%-13.94% of the phenotypic variance and the mean value was 6.33%. CAAS2050 (R 2=13.94%) and B153(R 2=11.36%) kept the max value. Meanwhile, 9 loci were found by MLM method significantly at the level of P<0.01 which explained 2.80%-9.22% of the phenotypic variance and the mean value was 5.16%. P89(R 2=9.22%) and P3*(R 2=8.28%) kept the max value. A total of 7 loci were detected in common by GLM and MLM. 【Conclusion】Genetic diversity and population structure of 595 accessions were analyzed through SSR markers. In the two association analysis models, 12 markers were associated with nine traits including stem node number, plant height, peduncle length, diameter of main stem, panicle length, panicle diameter, primary branch number per panicle, spikelet number per primary branch, protein content by GLM. Nine markers were associated with eight traits including stem node number, peduncle length, leaf width, diameter of main stem, panicle diameter, primary branch number per panicle, spikelet number per primary branch, 1000-grain weight by MLM.

    Genetic Diversity of Common Millet Resources Assessed with EST-SSR Markers
    SHI TianTian, HE JieLi, GAO ZhiJun, CHEN Ling, WANG HaiGang, QIAO ZhiJun, WANG RuiYun
    Scientia Agricultura Sinica. 2019, 52(22):  4100-4109.  doi:10.3864/j.issn.0578-1752.2019.22.014
    Abstract ( 248 )   HTML ( 17 )   PDF (3288KB) ( 292 )   Save
    Figures and Tables | References | Related Articles | Metrics

    【Objective】The objective of this study is to analyze the genetic diversity and relationship of common millet accessions (six different ecotopes at home and abroad) by microsatellite markers, to provide available data for classification, selection and utilization of elite germplasm resources. 【Method】 One hundred and forty-four SSRs (64 high motif nucleotide sequence repeat and 80 low ones) are used to identify polymorphisms in ninety-six common millet accessions (71 home accessions and 25 abroad accessions). Genetic diversity parameters were calculated using software PowerMarker 3.25 and PopGen 1.32. Genetic distance and Structure on accessions were classified with software MEGA 5.0 and Structure 2.2, respectively. PCA (principal component analysis) was conducted by software Ntsys 2.11. 【Result】 Using 144 EST-SSR markers, a total of 368 observed alleles (Na) were detected with 2-3 alleles (mean = 2.5556) per locus. The observed heterozygosity (Ho) ranged from 0.4070 (RYW15) to 0.9789 ( RYW85) with an average of 0.8288. The expected heterozygosity (He) ranged from 0.4369 ( RYW59) to 0.6693 ( RYW58) with an average of 0.5535. The Nei's gene diversity index ranged from 0.4344 (RYW59) to 0.6653 (RYW58) with a mean of 0.5505. The polymorphism information content (PIC) ranged from 0.1811 (RYW68) to 0.7508 (RYW58) with an average of 0.4279. The Shannon diversity index (I) range was 0.6474 to 1.0956 with an average of 0.8415. In the case of genetic diversity parameters, the PIC and I of common millet accessions from Northern spring-sowing region were the most abundant than that of others. On the contrary, the accessions from Northwest spring & summer-sowing region were the lowest. For the different geographical regions accessions, the range of genetic distance was 0.0111 to 0.1425 and the scope of genetic consistency was 0.8672 to 0.9889. The genetic distance of accessions between Loess Plateau spring & summer-sowing region and Northern spring-sowing region was the least and their genetic consistency was the highest. The genetic distance between Northwest spring & summer-sowing region and North of China summer-sowing region was the largest and their genetic consistency was the lowest. UPGMA analysis divided 96 accessions into three groups (GroupⅠ, Ⅱ and Ⅲ). Group I were mainly Northern spring-sowing region common millet, Group Ⅱ were mainly foreign accessions, and Group Ⅲ were mainly Loess Plateau spring & summer-sowing region and Northern spring-sowing region accessions. Structure cluster divided resources into four groups. The red group contained Loess Plateau spring & summer-sowing region and Northern spring-sowing region accessions, which represented the gene pool of Loess Plateau and North. The green group included Northern spring-sowing region accessions, which represented the North gene pool. The blue group were Loess Plateau spring & summer-sowing region accessions, which represented the gene pool of Loess Plateau. The yellow group represented foreign gene pool. In terms of diversity parameters, the PIC value of GroupⅡwas the highest at 0.4606 and the Group Ⅳ was the lowest at 0.3539. The PCA analysis classified all accessions into six clusters, which are related to their geographical region. 【Conclusion】144 SSRs can evaluate 96 common millet resources accurately. The genetic relationships are related to their geographical region. Genetic diversity of accessions from Northern spring-sowing region are more abundant.

    CULTIVATION·PHYSIOLOGY
    Effects of Heterogeneous Salinity Across Rhizosphere on the Growth of Sorghum Seedlings
    ZHANG HuaWen,WANG RunFeng,XU MengPing,LIU Bin,CHEN ErYing,HUANG RuiDong,ZHOU YuFei,WANG HaiLian
    Scientia Agricultura Sinica. 2019, 52(22):  4110-4118.  doi:10.3864/j.issn.0578-1752.2019.22.015
    Abstract ( 250 )   HTML ( 29 )   PDF (453KB) ( 335 )   Save
    Figures and Tables | References | Related Articles | Metrics

    【Objective】Salt content is usually unevenly distributed in saline-alkali lands. Studies on growth and development, and the changes of physiological and biochemical indexes of sorghum seedlings under non-uniform salt stress could provide a theoretical basis for the cultivation of sorghum in saline-alkali land and the efficient exploitation and utilization of saline-alkali lands.【Method】Roots of sorghum were divided into two equal portions by a root-split method and put in uniform and non-uniform NaCl concentration solution, respectively. There were four treatments. No sodium chloride (denoted as 0/0) was the control, 0 and 200 mmol·L -1(denoted as 0/200), 50 mmol·L -1 and 150 mmol·L -1(denoted as 50/150) were non-uniform salinity treatments, and 100 mmol·L -1/100 mmol·L -1 (denoted as 100/100) were uniform salinity treatment. Healthy sorghum seedlings after growing for 14 days in a growth chamber were sampled for the determination of biomass, leaf area, SPAD, root morphology, osmotic regulators content, anti-oxidative enzyme activity, and photosynthetic parameters. 【Result】 Growth of sorghum both in uniform and non-uniform salt stress conditions was severely inhibited, and significant decrease of fresh weight, biomass, leaf area, root morphology, photosynthetic capacity, anti-oxidative enzyme activity and osmotic substance content accumulation was found. Dry weight per plant was increased by 21.19% and 62.71%, fresh weights of seedlings was increased by 35.39% and 86.44%, and leaf area was increased by 13.22% and 88.66%, respectively under 50/150 and 0/200 compared with those under 100/100. Under 50/150 treatment, fresh and dry weights of roots in the 50 mmol·L -1 side were 1.90 and 2.10 times of the 150 mmol·L -1 side. Under 0/200 treatment, fresh and dry weights of roots in 0 mmol·L -1 side were increased by 3.02 and 3.75 times compared with the 200 mmol·L -1 side. Likewise, local root morphology was affected significantly in non-uniform salt treatment. Root length, root volume, root tip number, and root branch number of sorghum seedlings in 50 mmol·L -1 side or 0 mmol·L -1 were significantly increased compared with 150 mmol·L -1 (50/150) or 200 mmol·L -1 (0/200) salt stress side, respectively. Root length, root volume, root tip number, and root branch number of the whole root were significantly increased under 0/200 (P<0.05) compared with the 100/100 treatment. Activities of SOD, CAT, and POD in leaves were significantly higher under non-uniform salt stress (P<0.05). Contents of proline and soluble sugars were significantly increased in leaves with a dramatic reduce in MDA content (P<0.05) under the non-uniform salinity treatments. Compared with seedlings under the 100/100 condition. Photosynthesis of sorghum was significantly enhanced under 0/200 and 50/150 salt stresses, which chiefly was reflected by notably increased photosynthetic rate, stomatal conductance, transpiration rate, and decreased intercellular CO2 concentration (P<0.05). With respect to indexes of fluorescence of photosynthesis, such as ΦPSⅡ, Fv/Fm, and ETR, their values under 50/150 and 0/200 were increased by 5.64% and 19.00%, 9.25% and 18.89%, and 1.93% and 6.89%, respectively. ΦPSⅡ and Fv/Fm under 0/200 were significantly different from those under 100/100 (P<0.05).【Conclusion】Both non-uniform and uniform salt stress treatments caused growth inhibition to sorghum seedlings. However, due to the root compensatory growth of low salt or salt-free side under the non-uniform salt stress condition, whole root morphology, leaf antioxidant enzymes activity, osmotic regulation ability, and photosynthetic capacity were improved in a certain degree. Thus, non-uniform salinity could relieve damages to sorghum seedling initiated by salt stress.

    Effects of Exogenous Nitric Oxide on Seed Germination and Starch Transformation of Sorghum Seeds Under Salt Stress
    YIN MeiQiang,WANG Dong,WANG JinRong,LAN Min,ZHAO Juan,DONG ShuQi,SONG Xi’E,ALAM Sher,YUAN XiangYang,WANG YuGuo,WEN YinYuan
    Scientia Agricultura Sinica. 2019, 52(22):  4119-4128.  doi:10.3864/j.issn.0578-1752.2019.22.016
    Abstract ( 328 )   HTML ( 20 )   PDF (481KB) ( 283 )   Save
    Figures and Tables | References | Related Articles | Metrics

    【Objective】To discuss the physiological and biochemical regulation of exogenous Nitric Oxide (NO) on the germination of sorghum seeds under salt stress, which provided a theoretical basis for revealing the germination physiology and chemical regulation of sorghum seeds. 【Method】Sorghum (variety: Jintian 08-1) seeds were cultivated with 0, 50, 100, 150, 200, 300, and 400 mmol·L -1 NaCl solution. According to the germination rate under different concentrations of NaCl, the suitable salt tolerance concentration, semi-lethal concentration, and limiting concentration of sorghum seeds at the germination stage were defined. Sorghum seeds pretreated with 0.05, 0.1, 0.2, 0.4, 0.6 and 0.8 mmol·L -1 sodium nitroprusside (SNP, NO donor) for 12 h at 25℃ in dark, then were cultured in salt solution of 150 mmol·L -1 NaCl. The germination potential and germination rate were counted at cultured 36 h and 72 h, respectively. Proline content, malondialdehyde content and starch transformation related indexes were determined at cultured 5 days. Dinitrosalicylic acid is used in colorimetric determination of reducing sugars and to analyze amylase activity by quantitation of enzymatically released reducing sugar. The content of soluble sugar and starch were determined by anthrone method. Proline content and malondialdehyde (MDA) content were measured by acid-ninhydrin method and thiobarbituric acid method, respectively. The germination rate, germination energy, water absorption capacity of seeds, amylase activity, starch and sugar content, proline and other indexes were determined and analyzed to investigate the effects of exogenous NO on sorghum seed germination and starch transformation under salt stress. 【Result】The germination of sorghum seeds was obviously inhibited by more than 100 mmol·L -1 NaCl. When NaCl concentration was 150 mmol·L -1, the germination rate of sorghum seeds was 63.17%. 400 mmol·L -1 NaCl completely inhibited sorghum seeds germination. Pretreatment with SNP greatly relieves the inhibitory effect of the following salt stress to sorghum seeds germination, especially during the early stage of germination (36 h). 0.05 mmol·L -1 SNP alleviated the inhibition of salt stress on seed germination, seed germination potential, germination rate and germination index were 14.44%, 12.22% and 18.07% higher than those of the control, respectively (P<0.05). SNP increased the content of proline and soluble sugar in sorghum seeds by 18.97% and 41.43% respectively, which reduced osmotic potential, promoted water absorption and alleviated osmotic stress caused by NaCl. At the same time, the content of MDA decreased by 17.79% compared with NaCl treatment alone. Further investigations showed that pretreatment with NO donor dramatically stimulated the activities of amylase under salt stress by 17.20% compared with NaCl on the first day after treatment, and accelerated the degradation of starch, increased the content of reducing sugar. By the 5th day of SNP+NaCl treatment, the starch content decreased by 19.17%, and the content of soluble sugar and reducing sugar increased by 41.4% and 41.0%, respectively, compared to NaCl treatment. These newly produced substances provided energy for seed germination, and improved the salt resistance of sorghum seeds during germination period. 【Conclusion】According to our results, exogenous NO could regulate the amylase activity and osmotic regulation ability of sorghum seeds during germination period, improved their resistance to salt stress, and promoted seed germination.

    Effects of Black Full Film Mulching on Soil Temperature and Humidity and Weed Control in Root Zone of Sorghum
    ZHANG JianHua,GUO RuiFeng,CAO ChangLin,BAI WenBin
    Scientia Agricultura Sinica. 2019, 52(22):  4129-4138.  doi:10.3864/j.issn.0578-1752.2019.22.017
    Abstract ( 308 )   HTML ( 9 )   PDF (437KB) ( 278 )   Save
    Figures and Tables | References | Related Articles | Metrics

    【Objective】Soil temperature, moisture and tillage measures are important factors affecting crop growth and yield in rain-fed arid areas. It is of great significance to clarify the effect of full-film mulching on the soil environmental conditions in the root of sorghum, as well as its inhibitory effect on weeds, in order to promote the increase of sorghum yield in rain-fed arid areas. 【Method】The experimental site is located in The Institute of Shanxi Academy of Agricultural Sciences test base. Jinnuo 3 is the tested variety. The experiment adopts sequential arrangement design. Black full-film mulching, white full-film mulching and bare land cultivation experiments were carried out in 2017 and 2018, respectively. The effects of full-film mulching on the daily temperature of 0-15cm soil in the root zone of sorghum, soil moisture content of 0-200 cm soil layer, weed control, the growth, yield and benefit of sorghum were analyzed.【Result】The results showed that black full-film mulching could effectively improve the soil temperature of the surface layer in each growth period, soil temperature was lower and made the daily temperature of 0-15cm soil by an average of 1.14℃(P<0.05), compared with the white full-film mulching . The black and white full-film mulching provided the same degree of soil moisture conservation, the average soil moisture content of each soil layer was slightly higher than white full-film mulching. and increased by 1.89 percentage points on average compared with bare land cultivation, which significantly increased (P<0.05)the moisture content of 0-160 cm soil layer. The black full-film mulching significantly reduced the amount of sorghum weeds in the field. The control effect on broadleaf weeds and grass weeds reached 96% and 93% respectively, which was superior to the white full-film mulching(P<0.05)and had more thorough weed control effect. It was no obvious influence on sorghum seedling rate, ear length, number of first-stage branches and grain number per ear, but had an effect on sorghum plant height, plant height uniformity, birth stage, thousand grain weight, yield and benefit when sorghum was planted on black full-film mulching . The plant height and plant height uniformity of sorghum covered with the black full film for 60 days were higher than that covered with white full-film. The growth period of black full-film mulching sorghum was the same as that of bare land cultivation, while that of white full-film mulching sorghum was shorter, shorter by 4-6 days than that of bare sorghum. The thousand-grain weight and yield of black full-film mulching were significantly higher than that of white full-film mulching and bare land cultivation (P<0.05). Compared with white full-film mulching, the thousand-grain weight increased by 3.72% and 3.78% respectively, and 6.95% and 7.06% respectively compared with bare land cultivation. The yield was 6.72% and 6.94% higher than that of the whole white full-film mulching, 19.27% and 20.03% higher than that of bare land cultivation, respectively. The black full-film mulching increased 1 529.82 yuan/hm 2 and 1 599.76 yuan/hm 2 respectively compared with the white full-film mulching, and 3 025.38 yuan/hm 2 and 3 215.52 yuan/hm 2 respectively compared with the bare one.【Conclusion】It is suggested that black full-film mulching should be used instead of the traditional white full-film mulching in sorghum production in rain-fed arid areas, so as to promote the high yield of sorghum.

    Effects of Different Intercropping Patterns on Photosynthesis Production Characteristics and Water Use Efficiency of Proso Millet
    GONG XiangWei,DANG Ke,LI Jing,LUO Yan,ZHAO Guan,YANG Pu,GAO XiaoLi,GAO JinFeng,WANG PengKe,FENG BaiLi
    Scientia Agricultura Sinica. 2019, 52(22):  4139-4153.  doi:10.3864/j.issn.0578-1752.2019.22.018
    Abstract ( 392 )   HTML ( 35 )   PDF (3504KB) ( 418 )   Save
    Figures and Tables | References | Related Articles | Metrics

    【Objective】The propose of this study was to select the suitable proso millet-mung bean intercropping patterns in semi-arid region of northwest through studying the effects of different intercropping systems on the photosynthetic production and water use efficiency of proso millet, which can provide the basis for high yield, high efficiency production and ecological environmental protection.【Method】Field experiments were conducted in 2017 and 2018 in Yulin Modern Agriculture Demonstration Garden, Shaanxi. Four intercropping patterns were designed, 2 rows proso millet and 2 rows mung bean (2P2M), 4 rows proso millet and 2 rows mung bean (4P2M), 4 rows proso millet and 4 rows mung bean (4P4M), 2 rows proso millet and 4 rows mung bean (2P4M). The treatments containing proso millet (SP) and mung bean (SM) served as the controls. Photosynthetic characteristics and chlorophyll fluorescence parameters of leaves of proso millet as well as soil water distribution and utilization efficiency were conducted and the yield benefit was analyzed.【Result】The chlorophyll content, net photosynthesis rate, stomatal conductance, and transpiration rate of the flag leaf at anthesis stage was increased by 2.9%-13.5%, 5.0%-32.3%, 1.3%-6.3%, and 2.1%-8.7% than the single-plant systems, and thus the production capacity in the leaves of proso millet was improved. Meanwhile, proso millet//mung bean intercropping significantly increased the maximal photochemical efficiency of photosystem II (PSII) (Fv/Fm), the photochemical quenching coefficient (qL), the actual PSII efficiency (ΦPSII) and decreased non-photochemical quenching coefficient (NPQ). This led to enhance the ability to capture and transform light energy, reducing ineffective light leakage loss and heat loss, and improving the utilization ability of high intensity light for intercropping systems. The soil water content was significantly reduced and the reduction in the middle layer (60-140 cm) was significantly higher than that in the upper layer (0-40 cm) and the lower layer (160-200 cm). The changes in soil deep structure were related to the root depth collocation. Intercropping could improve the water use efficiency, and 2P2M, 4P2M, 4P4M and 2P4M increased by 11.5%, 2.3%, 20.8% and 30.1% compared with monoculture, respectively. Further, the biomass and yield of proso millet under intercropping were also significantly increased. The yield under 4P2M and 2P4M intercropping was 6.7% and 36.8% higher than the monoculture.【Conclusion】Photosynthetic production capacity of proso millet could be promoted by proso millet//mung bean intercropping, and land use efficiency in the semi-arid region of northwest could be improved. Under this experimental condition, 2P4M intercropping system was the suitable combination for the northwest dry farming areas to promote the application.

    Effect of Sowing Date on Agronomic Traits and Starch Physicochemical Properties of Proso Millet
    LUO Yan, QU Yang, YANG QingHua, ZHANG WeiLi, GONG XiangWei, LI Jing, GAO XiaoLi, GAO JinFeng, YANG Pu, WANG PengKe, FENG BaiLi
    Scientia Agricultura Sinica. 2019, 52(22):  4154-4165.  doi:10.3864/j.issn.0578-1752.2019.22.019
    Abstract ( 258 )   HTML ( 28 )   PDF (2950KB) ( 275 )   Save
    Figures and Tables | References | Related Articles | Metrics

    【Objective】 The purpose of this study was to analyze the effects of different sowing date on proso millet (Panicum miliaceum L.) agronomic traits and grain starch physiochemical properties, provide theoretical basis for the subsequent study of the mechanism of sowing date on proso millet.【Method】The experiment was carried out in a pot, and Shaanmei No. 1 was used as the test material. Four kinds of sowing dates were set on April 20 (B1), May 10 (B2), May 30 (B3), and June 20 (B4). Different sowing dates, the soil moisture was sufficient during the whole growth period. In 2017, the morphological indexes, grain shape and grain physicochemical properties of the seeds of the proso millet were studied. The plant height, ear length, ear stem length, number of ear branches, 1 000-grain weight, the seeds length, width and roundness of proso millet were analyzed under different sowing dates. In the meantime, the crystal structure, particle size distribution, amylose content, and the enthalpy and gelatinization properties of starch were studied. The correlation of amylose content, enthalpy characteristics and gelatinization properties of starch with morphological index, particle size distribution and particle size parameters were analyzed. 【Result】 The results showed that with the delay of sowing date, the plant height, ear length and ear stem length of proso millet were significantly increased, the main stem tillers and branches were significantly decreased, and the number of secondary spike branches and grain width were significantly decreased. The size distribution of grain starch granules showed a bimodal distribution, and compared with other sowing dates, the particles proportion of B1 had the highest > 28 μm (25.5%) and the lowest 5-28 μm (67.5%) starch granule. The X-ray diffraction pattern showed that changing the sowing date couldn’t affect the crystal type of the proso millet starch, but affected the diffraction peak intensity of the X-ray diffraction pattern. The amylose content (1.3%) of B1 was significantly higher than that in the other sowing dates (0.18%-0.53%). Among the indicators related to the enthalpy characteristics of grain starch in different sowing dates, the gelatinization onset temperature (To), peak temperature (Tp) and conclusion temperature (Tc) showed a tendency of increasing first and then decreasing, while the thermal enthalpy (ΔH) had no significant difference. There were significant differences in the gelatinization properties of proso millet starch under different sowing dates. The peak viscosity (Pv), through viscosity (Tv), final viscosity (Fv) and breakdown (BD) of B3 were significantly higher than the others, while the setback (SB) and peak temperature (PT) were significantly lower than other treatments. With the delay of sowing date, the Pv and BD of proso millet starch increased first and then decreased. B1 starch had the strongest hot paste stability, B3 starch had the strongest cold paste stability and the worst hot paste stability. The cold paste stability of B2 starch was the worst, while the cold paste and hot paste stability of B4 were at an intermediate level. 【Conclusion】 Appropriate sowing date could provide sufficient light and temperature conditions to provide a better environment for the growth of proso millet. Early sowing date significantly increased the 1 000-grain weight of proso millet kernels, the grain was fuller, and the average grain size of grain starch increased, with higher amylose content and nutritional value, which was more suitable for processing hot foods. The sowing date didn’t affect the crystal type of starch, but affected the intensity of the X-ray diffraction peak, the gelatinization characteristics and other indicators of the starch.

    Responses of Fertilization on Sorghum Grain Yield, Quality and Nutrient Utilization to Soil Fertility
    WANG JinSong,DONG ErWei,WU AiLian,BAI WenBin,WANG Yuan,JIAO XiaoYan
    Scientia Agricultura Sinica. 2019, 52(22):  4166-4176.  doi:10.3864/j.issn.0578-1752.2019.22.020
    Abstract ( 347 )   HTML ( 24 )   PDF (443KB) ( 305 )   Save
    Figures and Tables | References | Related Articles | Metrics

    【Objective】Responses of sorghum grain yield , quality and NPK utilization to inherent soil fertility, and their interaction were explored to provide theoretical basis for best nutrient management according to soil fertility. 【Method】Pot experiment was conducted in greenhouse. Soil was collected from three treatments of long-term fertilizer application experiment for 6 years, which were without fertilizer, NPK application and NPK application along with animal manure and straw returning to field, respectively. They were termed as low soil fertility (LSF), medium soil fertility (MSF) and high soil fertility (HSF), correspondingly. For each soil fertility, there were two treatments for pot experiment: without fertilizer (NF) and fertilizer application (CF). Plant and grain of sorghum were harvested after maturity. NPK accumulation in plant above ground and grain were calculated according to NPK concentration and biomass of each part of plant. The contents of starch, tannic and protein of grain were determined. 【Result】For LSF, MSF and HSF, a similar biomass and yield were gained if fertilizer was applied. They were significantly affected by inherent soil fertility if fertilizer was withdrawn. Soil fertility did not affect starch content of grain, which was 67.99%-69.33%, if fertilizer was not applied. However, HSF combined with fertilizer application resulted in 60.75% starch content in grain. For all treatments, the highest of tannin content was observed in grain of LSF without fertilizer. Fertilizer application significantly decreased tannin content of grain when sorghum was cultivated with LSF and HSF, only 70% of that was produced by LSF combined with NF. Protein content was promoted with the increase of inherent soil fertility, and was doubled by fertilizer application whatever soil fertility was. When fertilizer was applied, the contributions of soil fertility to yield were 90.25%, 51.75% and 8.5% for LSF, MSF and HSF, respectively. NPK accumulation of both grain and plant aboveground was regulated by inherent soil fertility. Fertilizer enhanced NPK absorption for all soil fertility treatments. For example, N accumulation in grain and plant, induced by fertilizer application, were 1.8 and 1.9 times of those when fertilizer was withdrawn under conditions of HSL. NPK harvest indices were enhanced by fertilizer application if soil fertility was either low or medium; whereas diminished NPK harvest indices were noticed with high soil fertility.【Conclusion】The potential sorghum grain yield can be gained for low soil fertility by means of fertilizer application. Without fertilizer, inherent soil fertility has a significant effect on grain yield. However its impacts on content of starch, tannin and protein can be neglected. Low soil fertility, combined withdrawn fertilizer, promotes starch and tannin accumulation in grain. Fertilizer application has relative more influence on grain protein content than soil fertility does. Fertilizer application diminishes nutrient harvest index and nutrient use efficiency if inherent soil fertility is high.

    Effect of Fertilization Location and Amount on Dry Matter Accumulation, Translocation and Yield of Hybrid Millet
    LI YongHu,CAO MengLin,DU HuiLing,GUO PingYi,ZHANG HaiYing,GUO MeiJun,YUAN XiangYang
    Scientia Agricultura Sinica. 2019, 52(22):  4177-4190.  doi:10.3864/j.issn.0578-1752.2019.22.021
    Abstract ( 436 )   HTML ( 23 )   PDF (1987KB) ( 454 )   Save
    Figures and Tables | References | Related Articles | Metrics

    【Objective】 This study was to probe the effects of nitrogen, phosphorus and potassium fertilizer amount and location on dry matter accumulation, translocation and yield of hybrid millet, provide theoretical basis for high yield and efficient planting and development of light simplified cultivation techniques. 【Method】 Taking hybrid millet (Setaria italica) cultivar of Zhangzagu10 as the tested material, a field experiment, cultivated with plastic film mulching, was conducted during 2016-2017 at the Innovation Zone of Shanxi Agricultural University by quadratic regression orthogonal rotation combination design. These 5 factors included nitrogen, phosphorus, potassium fertilizer rates, the horizontal distance to seed and depth of application, and each factor had 5 levels. All the fertilizers were basal applied in the designed rate and position, Nitrogen fertilizer is urea containing 46%N, phosphate fertilizer is superphosphate containing 16%P2O5, and potassium is sulfate containing 50%K2O. At elongation, heading, flowering, maturity, 3 clumps of millet plants were taken to examine dry matter accumulation. Harvested in early October, weighted and calculated the yield after threshing and drying, to study the effects of fertilization amount and fertilization position on dry matter accumulation, transport and yield in different growth stages of millet. The correlation between the tested index with the fertilizer rate and position were established using multivariate linear regression model 【Result】 (1) Higher yield levels requires higher supply levels of N, P and K, and the ratio of P and K increase relatively. (2) The order in the response degree on dry matter accumulation was nitrogen>phosphorus>potassium>fertilization horizontal distance>fertilization application depth; the order in the response degree on dry matter translocation was potassium>fertilization application depth>phosphorus>nitrogen>fertilization horizontal distance; the order in the response degree on yield was nitrogen>phosphorus>potassium>fertilization application depth>fertilization horizontal distance. (3) Nitrogen, phosphorus had an extremely significant effect on dry matter accumulation in main growth periods. The interaction between nitrogen and phosphorus in vegetative growth stage was negative, while in reproductive growth stage was positive. (4) As crop growth period goes on, the effects of potassium, fertilizer horizontal distance,and fertilizer application depth on dry matter accumulation change from negative to positive, and the degree of effect increases. The distance between the best fertilization location and the sowing location increased first and then decreased. (5) The regression between five factors and dry matter accumulation and translocation was extremely significant, and the fitting degree was higher. Therefore, it can be used in the actual production forecast. 【Conclusion】 Under the conditions of this experiment, the optimal scheme for Zhangzagu 10 was 16.80-18.75 cm of fertilization horizontal distance, 20.80-23.75 cm of fertilization application depth, 225 kg·hm -2 of N, 136.35-153.63 kg·hm -2 of P2O5, 93.56-108.63 kg·hm -2of K2O.