Table of Content

16 December 2018, Volume 51 Issue 24

Previous Issue    Next Issue

CROP GENETICS & BREEDING·GERMPLASM RESOURCES·MOLECULAR GENETICS

Identification and Analysis of Salt Tolerance of Wheat Transcription Factor TaWRKY33 Protein

ZHANG HuiYuan,LIU YongWei,YANG JunFeng,ZHANG ShuangXi,YU TaiFei,CHEN Jun,CHEN Ming,ZHOU YongBin,MA YouZhi,XU ZhaoShi,FU JinDong

Scientia Agricultura Sinica. 2018, 51(24):  4591-4602.  doi:10.3864/j.issn.0578-1752.2018.24.001

Abstract ( 769 )   HTML ( 144 )   PDF (2880KB) ( 683 )   Save

Figures and Tables | References | Related Articles | Metrics

【Objective】 WRKY transcription factors are one of the largest families of transcriptional regulators in plants which functions in the regulation of various physiological programs, including pathogen defense, growth, development and abiotic stresses. Wheat transcription factor TaWRKY33 enhanced drought and heat tolerance in transgenic Arabidopsis. To further investigate its function and stress response mechanism, this article studied its salt tolerance and screened wheat cDNA library to obtain its putative interacting proteins by yeast two-hybrid system. Meanwhile, dual luciferase system was used to detect transcriptional activity of TaWRKY33 transcription factors.【Method】 TaWRKY33 was tested under salt stress using quantitative real-time PCR (qRT-PCR) based on SYBR Green I technology. The coding sequence of TaWRKY33 was cloned into pBI121 driven by CaMV35S promoter. The construct was transformed mediated by Agrobacterium into Arabidopsis plants (Col-0) to obtain transgenic lines. Meanwhile, pWMB110- TaWRKY33 binary vector was used to create over expressed wheat lines. Homozygous T₃ seeds of Arabidopsis transgenic lines and T₂ wheat overexpression lines were used for salt tolerance analysis. The wheat cDNA was used as the template for amplifying the TaWRKY33 coding sequence, and the bait plasmid pGBKT7- TaWRKY33 was constructed. We transformed the recombinant plasmid and cDNA library into yeast cell AH109. We screened positive clones via SD/-Trp/-Leu/-His/-Ade and SD/Raf/Gal/X-α-gal plate. Predicted clones were sequenced and analyzed by BLAST. The protoplasts of wheat were prepared, and the reporters and effector plasmids were transformed by transient expression experiments, and the relative fluorescence values were calculated to illustrate transcription activity of transcription factors. 【Result】 qRT-PCR analysis showed that TaWRKY33 was induced by salt. The transient expression experiment of double luciferase showed that TaWRKY33 could activate the luciferase activity in wheat cells. From the perspective of functional analysis, formed longer roots compared with wild type plants, the fresh weight of overexpressing Arabidopsis was significantly different from that of wild type. Importantly, from the perspective of fresh weight, relative electrical conductivity and Na ⁺ content in salt treatment showed that wheat with overexpression of TaWRKY33 had better salt tolerance than control. Through preliminary analysis, the candidate proteins screened by yeast two-hybrid system showed influence on signal transduction and immune process, which demonstrates that TaWRKY33 plays an important role in stress signal transduction and gene transcription regulation in plants.【Conclusion】 Salt-inducible TaWRKY33 improved salt tolerance in transgenic Arabidopsis and wheat and it has potential transcriptional activation activity in cells; TaWRKY33 might function via interacting with a diverse array of protein partners.

Regulation of GT and GATA Transcription Factors on Promoter Function of BnA5.FAD2 and BnC5.FAD2 Genes in Brassica napus

LIU Fang,XIAO Gang,GUAN ChunYun

Scientia Agricultura Sinica. 2018, 51(24):  4603-4614.  doi:10.3864/j.issn.0578-1752.2018.24.002

Abstract ( 379 )   HTML ( 32 )   PDF (3237KB) ( 325 )   Save

Figures and Tables | References | Related Articles | Metrics

【Objective】 Fatty acid desaturase 2 gene (FAD2) is an important gene for controlling oleic acid content in rapeseed. And in this paper, the interaction between GATA family and BnA5.FAD2 and BnC5.FAD2 gene promoters or GT family transcription factors and BnA5.FAD2 and BnC5.FAD2 gene promoters was studied to make sure the transcription regulation mechanism to provide the theoretical basis for high oleic acid breeding. 【Method】 The potential cis-elements were predicted by deletion of promoter fragments and bioinformatics analysis, and candidate transcription factors were screened from PlantTFDB transcription factor database. Real-time PCR (qRT-PCR) was used to detect the expression pattern of transcription factors to further screen candidate transcription factors by comparison with BnA5.FAD2 and BnC5.FAD2 gene expression patterns. Transcription factors were co-transformed with BnA5.FAD2 and BnC5.FAD2 gene promoters into yeast and verified interaction relationship between promoter and transcription factors by yeast one-hybrid. The transcription factors were transformed into Arabidopsis thaliana with BnA5.FAD2 and BnC5.FAD2 gene promoter sequence, and the reporter gene GFP was detected by western blot to analyze the effects of transcription factors on promoters. 【Result】 After knocking out the GT or GATA cis-elements from BnA5.FAD2 and BnC5.FAD2 gene promoters respectively, the GFP protein abundance decreased, which indicate that GT and GATA cis-elements play important roles in regulating gene transcription. Yeast one-hybrid results showed that the GATA family transcription factors (Bna010243-1, Bna026124-1, Bna026124-2) and the GT family transcription factors (Bna010915 and Bna013749) can interact with BnA5.FAD2 and BnC5.FAD2 gene promoters. Western blot analysis showed that when the GATA family transcription factor and the promoter fragment containing GATA elements were co-transformed into Arabidopsis thaliana, the GFP protein content was significantly higher than that of no transcription factor. When the GATA element was knocked out, the GFP protein content did not change significantly. When the GT family transcription factor and the promoter fragment containing the GT element were co-transformed into Arabidopsis thaliana, the GFP protein content changed significantly. When the GT element was knocked out, the GFP protein content did not change significantly.【Conclusion】 The GATA family transcription factors Bna010243-1, Bna026124-1, Bna026124-2 can interact with the GATA elements in the BnA5.FAD2 and BnC5.FAD2 gene promoters to enhance gene expression levels. The GT family transcription factor Bna010915 interacts with the GT elements in the BnA5.FAD2 and BnC5.FAD2 gene promoters to positively regulate gene expression; Bna013749 interacts with the GT elements in the BnA5.FAD2 and BnC5.FAD2 gene promoters to negatively regulate gene expression.

TILLAGE & CULTIVATION·PHYSIOLOGY & BIOCHEMISTRY·AGRICULTURE INFORMATION TECHNOLOGY

New Grouped Harvesting-Based Population Structures of Cotton

DONG HeZhong,ZHANG YanJun,ZHANG DongMei,DAI JianLong,ZHANG WangFeng

Scientia Agricultura Sinica. 2018, 51(24):  4615-4624.  doi:10.3864/j.issn.0578-1752.2018.24.003

Abstract ( 381 )   HTML ( 25 )   PDF (364KB) ( 258 )   Save

Figures and Tables | References | Related Articles | Metrics

The construction of rational population structures is an important cultivation basis to achieve high yield and quality of cotton. ‘Small-sized plant under high plant density’, ‘moderate-sized plant under moderate plant density’ and ‘large-sized plant under low plant density’ are three types of traditional cotton population structures in China, which have been widely used in China's major cotton planting regions of Northwest inland, Yellow River and Yangtze River valley, respectively, and have played key roles in achieving stable and high yields of cotton in the nation. However, in the new era of cotton industry development, there occur such disadvantages that the traditional population structures are not suitable for grouped harvesting as well as both fiber quality and production efficiency improvements. The exploration of new population structures has become an important approach in the new period of cotton cultivation. In this paper, we concisely reviewed the main features and the disadvantages of traditional population structures. Based on the needs of light and cost-saving cultivation as well as quality improving and efficiency increasing in the new era, it was suggested that constructing 3 new types of population structures adapted to grouped harvesting, ‘reduced plant density with healthy plants’, ‘increased plant density with robust plants’, and ‘direct seeding and close planting with short plants’ to substitute the three traditional structures. On this basis, the key indicators and regulation technologies of the 3 new population structures were mainly discussed, and the future development of the new population structures both in research and practice were also prospected.

Effects and Mechanism of Higher Plant Density on Directly-Sown Rapeseed in the Yangtze River Basin of China

KUAI Jie,WANG JiJun,ZUO QingSong,CHEN HongLin,GAO JianQin,WANG Bo,ZHOU GuangSheng,FU TingDong

Scientia Agricultura Sinica. 2018, 51(24):  4625-4632.  doi:10.3864/j.issn.0578-1752.2018.24.004

Abstract ( 435 )   HTML ( 46 )   PDF (370KB) ( 341 )   Save

References | Related Articles | Metrics

The Yangtze River Basin is the main producing area of rapeseed in China, where the rapeseed area and total output accounts for about 90% of those of China. Compared with the developed country, directly-sown rapeseed in the Yangtze River Basin of China had lower density, lower yield, and lower mechanical rate but a higher fertilizer rate and higher labour costs. The high production costs, low economic performance resulted in farmers’ negative attitude toward planting rapeseed, which hindered the development of rapeseed production in this area. In recent years, the production practice all over the place showed that higher plant density was an effective measure to promote plant benefit and narrow the yield gap with the developed country. Based on relevant studies, this article summarized the effects and mechanism of higher plant density on rapeseed yield, seed quality, the resistance of stem lodging and pod shattering, nitrogen and light use efficiency, stem rot caused by Sclerotinia sclerotiorum, and weed occurrence. Based on this summary, the cultivation techniques that “the higher density can increase yield, compensate for late planting, adequately control weeds, lower nitrogen requirement, increase lodging resistance and facilitate mechanized harvesting” were brought forward, which could provide theoretical basis on establishing rapeseed population with high yield and high lodging resistance, and technical support for simple and efficient production of rapeseed in the Yangtze River Basin of China.

PLANT PROTECTION

Analysis of Magnaporthe oryzae Avirulent Genes in the Infected Hybrid Rice Combinations Derived from a Sterile Line of Guang 8 A

WANG WenJuan,SU Jing,YANG JianYuan,WEI XiaoYan,CHEN KaiLing,CHEN Zhen,CHEN Shen,ZHU XiaoYuan

Scientia Agricultura Sinica. 2018, 51(24):  4633-4646.  doi:10.3864/j.issn.0578-1752.2018.24.005

Abstract ( 367 )   HTML ( 16 )   PDF (1317KB) ( 235 )   Save

Figures and Tables | References | Related Articles | Metrics

【Objective】 The objective of this study is to analyze the avirulent genotypes of Magnaporthe oryzae derived from the hybrid rice combinations of Guang 8 A, and to provide a reference for rational distribution of cultivars with different blast resistant genes in South China. 【Method】 A set of single-spore strain was subjected to pathotype analysis using blast monogenic differential lines. According to the functional markers of 8 Avr genes, which had been cloned and were associated with the rice blast pathogenicity, the haplotypes of Avr genes were analyzed. The DNA, which extracted from the 27 strains of rice blast fungi, was used as a template for PCR amplification. The PCR products of avirulent full gene or CDS region were analyzed by agarose gel electrophoresis and sequencing, and their sequences were compared to corresponding avirulent genes.【Result】 The tested strains showed high frequency (＞85%) of avirulence to the 5 monogenic differential lines, such as IRBLkh-K3 (Pikh), IRBLb-B (Pib), IRBLz5-CA (Pi2), NIL-e1 (Pi50) and IRBL9-W (Pi9), all strains were avirulent to IRBL9-W (Pi9) and NIL-e1 (Pi50). These strains showed relatively low frequency of avirulence (＜20%) to the 7 monogenic differential lines, such as IRBLks-F5 (Piks), IRBLa-A (Pia), IRBL19-A (Pi19) and so on, indicating that the strains from the combination of Guang 8 A showed different pathotypes to different rice blast-resistant lines. AvrPi9 and AvrPik fragments were almost present in all strains, and two haplotypes (AvrPik-D and AvrPik-E) of AvrPik were identified. But none of Avr1-CO39, AvrPii or AvrPia was amplified in any strain. The expected size products of AvrPiz-t, AvrPib and AvrPita could be detected in some strains, but they all appeared in lower frequency and different mutation types in the tested strain. Amplicon sequencing of 7 strains (GD13-621, GD14-349, GD15-291, et al.) revealed that the sequences of AvrPi9, AvrPita and AvrPiz-t were identical to those of the respective avirulent strains. This result indicated that these 3 Avr genes had a stable gene structure. Compared to AvrPib in an avirulent strain, AvrPib in the tested strains contained 2 nucleotide changes or 3 consecutive nucleotide insertions in the gene upstream region. The results indicated that AvrPib had a rich haplotype. The sequences of AvrPik in 6 strains were highly consistent, only contained one nucleotide changes in the coding region (136C/A), resulting in one amino acid substitutions (46H/N), which showed two haplotypes of AvrPik (AvrPik-D or AvrPik-E).【Conclusion】 In the strains from the major rice cultivars of Guang 8 A in South China, the distribution of AvrPi9 and AvrPik was relatively wide. In the susceptible areas of the above cultivars, the resistant cultivars carrying Pi9 and Pik could be used as rotation planting cultivars.

Establishment of AS-real-time PCR for Quantitatively Detecting the H278R Allele in the SdhB Associated with Corynespora cassiicola in Cucumber

SUN BingXue,SHI YanXia,ZHU FaDI,XIE XueWen,CHAI ALi,LI BaoJu

Scientia Agricultura Sinica. 2018, 51(24):  4647-4658.  doi:10.3864/j.issn.0578-1752.2018.24.006

Abstract ( 285 )   HTML ( 17 )   PDF (1995KB) ( 262 )   Save

Figures and Tables | References | Related Articles | Metrics

【Objective】 The objective of this study is to establish a rapid and efficient allele specific real-time PCR (AS-real-time PCR) method for quantitative detection of the H278R mutation in the SdhB associated with Corynespora cassiicola in cucumber, and to verify the effect. 【Method】 A total of 24 single conidial strains of C. cassiicola were isolated from Daxing, Beijing. The method of mycelial growth inhibition was used to determine the EC₅₀ value to boscalid. Mycelium growth rate, spore outputs and pathogenicity of 4 susceptible (S) and 8 resistant (R) strains were measured in vitro. Primer pair Cc-SdhB-F/R was used to detect the sequence of SdhB and the base change of SdhB. Based on the sequencing results in SdhB by Cc-SdhB-F/R primers, specific primer pair B-H278R-2F/2R14 and internal primers B-H278R-TY-F/R were designed. An AS-real-time PCR reaction system was established and optimized. The specificity, sensitivity and melt curve of the system were also evaluated. DNA and spore suspension containing different proportions of H278R mutation were detected with the optimized reaction system, respectively. 【Result】 The sensitive frequency of C. cassiicola to boscalid was 66.67% in 24 strains and the EC₅₀ values ranged from 0.057 to 0.563 μg·mL ^-1. The resistance frequency of C. cassiicola to boscalid was 33.33% and the EC₅₀ values ranged from 5.395 to 11.710 μg·mL ^-1. Resistant and susceptible strains only significantly differed in terms of mycelium growth rate, and there was a significant negative correlation between the rate of mycelial growth and EC₅₀ values, but no significant difference in spore outputs and pathogenicity. Sequencing analysis showed that all the resistant strains carried SdhB-H278R mutation. The primers B-H278R-2F/2R14 were of great specificity, the specific fragment was amplified from the DNA of H278R strains, but not from the DNA of other fungal strains. The sensitivity of ordinary AS-PCR was 91 pg·μL ^-1, while that of AS-real-time PCR was 9.1 pg·μL ^-1, which was 10 times higher than that of ordinary AS-PCR. The standard curve established by AS-real-time PCR showed a fine linear relationship between ΔCT value and lg of H278R frequency, the correlation coefficient of the standard curve was 0.9857 and with high amplification efficiency (92.59%). The absorption peak of melting curve was single. The internal reference primers B-H278R-TY-F/R and the specific primer B-H278R-2F/2R14 had a single specific peak at 87.81℃and 91.62℃, respectively. The result of mixtures DNA and mixtures spore suspension to verify the standard curve showed a fine linear relationship between expected percentage and detected percentage (R ²=0.9998 and R ²=0.9922). As the proportions of H278R mutation in DNA and spore suspension decreased, the accuracy of the system gradually increased, and the detection limit was 5%. 【Conclusion】 An efficient, quantitative, and rapid AS-real-time PCR detection system was established for the detection of SdhB-H278R mutation site, which can provide a theoretical basis for the SDHIs resistance management.

SOIL & FERTILIZER·WATER-SAVING IRRIGATION·AGROECOLOGY & ENVIRONMENT

Influence of Sub-Region Priority Modeling Constructed by Random Forest and Stochastic Gradient Treeboost on the Accuracy of Soil Salinity Prediction in Oasis Scale

WANG Fei,YANG ShengTian,WEI Yang,YANG XiaoDong,DING JianLi

Scientia Agricultura Sinica. 2018, 51(24):  4659-4676.  doi:10.3864/j.issn.0578-1752.2018.24.007

Abstract ( 278 )   HTML ( 15 )   PDF (11238KB) ( 215 )   Save

Figures and Tables | References | Related Articles | Metrics

【Objective】 This study attempts to improve the prediction accuracy of soil salinity in arid oasis by building models preferentially in the sub-area of oasis. At the same time, the difference and uncertainty of accuracy between global model and sub-region model are quantified. 【Method】 Therefore, to investigate the above differences, this study used two machine learning methods (Random Forest, RF and Stochastic Gradient Treeboost, SGT) to quantify the above effects and to prove the necessity of the building model in the sub-region compared with the full-sample model with respect to the simulation precision under the complex background of an arid region. Twenty-seven environmental scenarios (twelve original and fifteen derivatives) were designed based on the driving factors (land use and landform) and response factors (Normalized Difference Vegetation Index, NDVI and electrical conductivity, EC), which reflected variety of variabilities in soil salinity. After analyzing the results, the following preliminary conclusions were drawn. 【Result】 The simulation results from 70.37% (19/27) of the scenarios showed that the predicted value of soil salinity from SGT was closer to the observed value from RF. Ten original sub-regions were modeled individually and compared with the full-sample model under the oasis scale (according to the 10 partition rules to reclassify the simulated values), and the result showed that the prediction accuracy of the former 70% scenario was higher than that of the latter. In particular, the regions of EC≤4 dS·m ^-1 and 2 ddS·m ^-1＜EC＜16 dS·m ^-1 should be modeled separately to predict the spatial variability of regional salinity. By combining the predictions of sub-regions and comparing them with the predicted values of the full-sample model, the former (all four different combination modes) showed a higher prediction accuracy than the latter. In addition, this result also indicated that the preferred medium for partitioning the sub-regions was soil electrical conductivity, followed by landform and land use. 【Conclusion】 The study proposes to establish a soil salinity model based on SGT preferentially on different landscape scales within the oasis, and then combine the predicted values of each landscape scale to improve the prediction accuracy of oasis soil salinity.

Influence of Long-term Fertilization on Community Structures and Colonization of Arbuscular mycorrhizal Fungi in a Brown Soil

GUO Jing,LUO PeiYu,YANG JinFeng,LI DongDong,HUANG YueYue,HAN XiaoRi

Scientia Agricultura Sinica. 2018, 51(24):  4677-4689.  doi:10.3864/j.issn.0578-1752.2018.24.008

Abstract ( 333 )   HTML ( 17 )   PDF (1063KB) ( 282 )   Save

Figures and Tables | References | Related Articles | Metrics

【Objective】AM (Arbuscular mycorrhizal) fungi plays important roles like improving the rhizosphere soil environment, promoting the uptake of nutrients by plants, enhancing resistance of plant, and increasing crop yield and quality. This study aimed to explore changes of community structures and colonization rate of AM fungi and to find out the main factors which affected the changes under a corn-soybean rotation system and a long-term fertilization for 38 years in a brown soil. 【Method】 Soil samples (0-20 cm) were taken from the six treatments of the long-term fertilization experiment in June 2016, including (1) no fertilizer (CK); (2) chemical N input (N); (3) chemical N and P input (NP); (4) chemical N, P and K input (NPK); (5) pig manure (M); (6) pig manure, chemical N and P (MNP). Then the soil samples were analyzed by using PCR-DGGE, gel-recovery, sequencing and trypan blue staining. Relationship between community and colonization rate of AM fungi and environmental factors were analyzed by Redundancy analysis and Canonical Correlation analysis. 【Result】 The result showed that the contents of alkali-hydrolysable nitrogen (AHN), available phosphorus (AP), available potassium (AK) , ammonium nitrogen (NH₄ ⁺-N), nitric nitrogen (NO₃ ^--N) and dissolved organic carbon (DOC) under organic fertilization treatments were significantly higher than them under the CK treatment and chemical fertilization treatments, and the trend was: organic fertilizer treatments > chemical fertilizer treatments > CK treatment. Compared with the CK treatment, soil pH was decreased in chemical fertilizer treatments and increased in organic fertilizer treatments. 22 bands of AM fungi from soil and 9 bands of AM fungi from root were obtained by gel-recovery, and 13 OTU were obtained by BLAST. The result of sequencing showed that AM fungi species isolated from soil samples were mainly Glomeromycota and Gigasporaceae, while infected AM fungi was only Glomeromycota. The cluster analysis showed that community structures of soil AM fungi were divided into three groups under a long-term fertilization in a brown soil, namely N treatment, organic fertilizer treatments and another fertilizer treatments. Community structures of infected AM fungi were also divided into three groups, namely NPK treatment, M treatment and NP treatment, and another fertilizer treatments. The spore density of AM fungi under organic fertilizer treatments was significantly higher than that under chemical fertilizer treatments and non-fertilizer treatment, and the trend was: organic fertilizer treatments > chemical fertilizer treatments > CK treatment. The trend of colonization rate of AM fungi under different fertilizer treatments was: NPK treatment > organic fertilizer treatments > another fertilizer treatments. Redundancy analysis showed that spore density was positively correlated with soil AHN, NH₄ ⁺-N, AP, AK, DOC and soil moisture content, and colonization rate was positively correlated with nitric nitrogen content. The colonization rate was positively correlated with spore density, while diversity index of AM fungi was neither correlation with colonization rate nor with spore density. Canonical Correlation analysis showed AHN, AK, DOC and NH₄ ⁺-N significantly influenced the ribotypes of AM fungi. 【Conclusion】 The long-term fertilization changed community structures of AM fungi by changing the physicochemical properties of the soil, and then affected colonization of AM fungi.

HORTICULTURE

Apple MdMYB32 Inhibits the Anthocyanin Biosynthesis by Its Own EAR Inhibitory Sequence

XU HaiFeng,YANG GuanXian,WANG YiCheng,JIANG ShengHui,WANG Nan,CHEN XueSen

Scientia Agricultura Sinica. 2018, 51(24):  4690-4699.  doi:10.3864/j.issn.0578-1752.2018.24.009

Abstract ( 396 )   HTML ( 12 )   PDF (2643KB) ( 651 )   Save

Figures and Tables | References | Related Articles | Metrics

【Objective】 In order to improve the metabolic mechanism of anthocyanin synthesis, several aspects of apple MdMYB32 in MYB transcription factors were studied, including the bio-informatics, the expression level and the function in the anthocyanin synthesis.【Method】 We cloned the MdMYB32 in Malus sieversii f. neidzwetzkyana F1 population and analyzed its phylogenetic tree and protein sequence. The expression level of MdMYB32 in different apple fruits with different stress treatments was studied. We verified its function in anthocyanin biosynthesis by transgene and analyzed its interaction by yeast one-hybrid.【Result】 qRT-PCR analysis showed that the expression level of MdMYB32 in 'Hongcui No. 9' with high anthocyanin content was lower than that in 'Hongcui No. 6' with low anthocyanin content. The expression level of MdMYB32 was negatively correlated with the content of anthocyanin. Both salt stress and cold stress could inhibit the expression of MdMYB32. The phylogenetic tree indicated that MdMYB32, AtMYB32, MdMYB16 and AtMYB4 were located in the same evolutionary branch, and MdMYB32 protein contained an EAR inhibitory sequence at the C-terminus. Overexpressing MdMYB32 in red-fleshed callus could inhibit the expression of ANS and reduce the anthocyanin content. However, when we overexpressed LESMdMYB32 (knocked out the EAR sequence of MdMYB32) in red-fleshed callus, we found that it could not affect the expression of ANS and the anthocyanin content. Yeast one-hybrid and Chip-PCR analyses showed that MdMYB32 and LESMdMYB32 could bind the promoter of ANS.【Conclusion】 MdMYB32 could bind the promoter of ANS and inhibit the anthocyanin biosynthesis by its own EAR inhibitory sequence.

Effects of Urea Application Combined with Different Amounts of Nano-Carbon on Plant Growth Along with Nitrogen Absorption and Utilization in Young Peach Trees

WANG GuoDong,XIAO YuanSong,PENG FuTian,ZHANG YaFei,GAO HuaiFeng,SUN XiWu,HE Yue

Scientia Agricultura Sinica. 2018, 51(24):  4700-4709.  doi:10.3864/j.issn.0578-1752.2018.24.010

Abstract ( 385 )   HTML ( 26 )   PDF (676KB) ( 344 )   Save

Figures and Tables | References | Related Articles | Metrics

【Objective】 In order to clarify whether carbon nanoscale could promote the growth of peach trees and to screen out the optimum application ratio of carbon and urea, it was expected to provide a theoretical basis for the application of carbon nanomaterials to improve the nitrogen fertilizer efficiency in the process of fruit tree cultivation. 【Method】 The experiment was conducted by using isotope tracer technology. The 2-year-old Rui pan 21/peaches was used as a test material and ¹⁵N urea was used in different doses under potting conditions (5 treatments: CK: 0 mL, T1: 5 mL, T2: 10 mL, T3: 15 mL, and T4: 20 mL). And the nano-carbon sol was tested to investigate the effects of nanocarbon on soil physical and chemical properties, peach growth and development, and nitrogen absorption and utilization. The pH value, redox potential and electrical conductivity of the soil, the dry diameter of 2 cm at the upper part of the plant and the dry weight of each part of the plant, the chlorophyll SPAD value of the leaf, the net photosynthetic rate, the structure of the root system, the total N content, and the ¹⁵N abundance of each part of the plant were measured. 【Result】 Application of nano-carbon significantly reduced soil pH value, increased soil oxidation-reduction potential, and affected the redox state of soil solution; with the increase of the amount of nano-carbon, the soil conductivity showed a tendency of decreasing at the early stage of treatment and increasing at a later stage. The application of nano-carbon promoted the growth of the root system of young peach trees. The net photosynthetic rate, chlorophyll content of peach leaves and diameter were increased. The total biomass accumulation of peach trees was highest under T3 treatment, which was 778 g and was 28.4% higher than that under CK. The application of nano-carbon increased the Ndff value of fine roots, coarse roots, lateral branches, spring shoot leaves and other organs of peach trees. Compared with CK, T1 treatment significantly increased the nitrogen distribution rate of the main trunk and the central trunk, while T3 and T4 treatment decreased the nitrogen distribution rate of the main trunk. The nitrogen utilization rate of peach plants was increased significantly with the application of nano-carbon, and the treated with T3 was the highest, being 45.2%, which was 66.5% higher than that under CK. With the increase the amount of carbon nanoscale, the nitrogen residue rate of soil increased. The treatments of T1, T2, T3 and T4 were 1.06 times, 1.35 times, 1.62 times and 1.70 times of CK, respectively, and the nitrogen loss rate decreased significantly. 【Conclusion】 The application of urea with nano-carbon could improve soil physical and chemical properties, effectively adsorb nitrogen in soil, significantly reduce nitrogen loss rate, increase plant nitrogen utilization and soil nitrogen residue, and promote root growth and plant morphology of peach trees.

ANIMAL SCIENCE·VETERINARY SCIENCE·RESOURCE INSECT

Expression Analysis of Five Genes in the Gonadal Axis of Small Tail Han Sheep and Sunite Sheep

ZHANG ZhuangBiao,DI Ran,LIU QiuYue,HU WenPing,WANG XiangYu,TIAN ZhiLong,ZHANG XiaoSheng,ZHANG JinLong,CHU MingXing

Scientia Agricultura Sinica. 2018, 51(24):  4710-4719.  doi:10.3864/j.issn.0578-1752.2018.24.011

Abstract ( 384 )   HTML ( 18 )   PDF (541KB) ( 237 )   Save

Figures and Tables | References | Related Articles | Metrics

【Background】With the continuous improvement of living standard, mutton with rich protein and low cholesterol content is increasingly favored in daily life, and the overall consumption demand of mutton is increasing year by year. However, in recent years, the shortage of mutton-based sheep products has caused the price of mutton to remain high, resulting in a contradiction between supply and demand of mutton. In the early researches on the performance of sheep, it was found that the reproductive performance had an important impact on the mutton production. Therefore, improving the fecundity of sheep is of great significance for changing the situation of slow turnaround and poor efficiency of meat sheep production in China. The litter size is the most important reproductive trait, but the litter size is a quantitative trait of low heritability and is controlled by micro-multiple genes. Therefore, traditional breeding methods are difficult to rapidly improve litter size. In recent years, with the advent of molecular marker technology, researchers have discovered some major genes that affect the fertility of sheep, such as BMPR1B, BMP15, GDF9 and other genes, afterwards, researches began to use conventional breeding methods combined with these molecular markers to cultivate new sheep breeds with high fecundity. Studies have shown that in addition to these major genes that have been discovered, there are still some genes that have a certain regulatory effect on the fecundity of sheep. Based on this situation, the purpose of this study was to explore the differential expression of candidate genes which may affect the fertility of sheep. 【Objective】 BMP2, BMP6, BMP7, CAST and CART, in the tissues associated with the gonadal axis (brain, cerebellum, hypothalamus, pituitary, uterus, ovary and oviduct) in Small Tail Han sheep and Sunite sheep, which would provide a reference for clarifying the mechanism of high fecundity of sheep. 【Method】 Polytocous Small Tail Han sheep and monotocous Sunite sheep were used as the experimental animals, and real-time fluorescence quantitative PCR was performed to detect the expression difference of these five genes in seven gonadal-related tissues in two sheep breeds. 【Result】 The results showed that BMP2 gene was expressed in all seven tissues of the gonadal axis. The expression of BMP2 in hypothalamus in Small Tail Han sheep was higher than that in Sunite sheep (P＜0.05). The expression of BMP2 in oviduct, ovary, pituitary and cerebellum in Small Tail Han sheep was higher than that in Sunite sheep (P＜0.01), however, the expression difference of this gene in the brain and uterus of the two sheep breeds was not significant (P＞0.05). The expression of BMP6 in pituitary, ovary and oviduct in Small Tail Han sheep was higher than that in Sunite sheep (P＜0.01), although the expression level of this gene in the hypothalamus and uterus of Small Tail Han sheep was higher than that of Sunite sheep, however, the expression difference was not significant (P＞0.05). The expression of BMP7 in pituitary and brain of Small Tail Han sheep was higher than that in Sunite sheep (P＜0.05), the expression of BMP7 in hypothalamus, oviduct and ovary of Small Tail Han sheep was higher than that of Sunite sheep (P＜0.01), but there was no significant difference in the expression of this gene in the cerebellum and uterus of Small Tail Han sheep and Sunite sheep (P＞0.05). The trace expression of CAST was found in hypothalamus and pituitary, and the higher expression in other tissues in two sheep breeds, the expression of CAST gene in oviduct and uterus of Small Tail Han sheep was higher than that of Sunite sheep (P＜0.01), however, the expression levels of this gene in the brains of Small Tail Han sheep and Sunite sheep were almost the same (P＞0.05). The CART was highly expressed in hypothalamus of two sheep breeds. The expression of CART gene in pituitary of Sunite sheep was higher than that of Small Tail Han sheep (P＜0.05), and the expression of CART in brain of Small Tail Han sheep was higher than that of Sunite sheep (P＜0.01), whereas, there was no significant difference in the expression of this gene in other tissues used in this experiment of two sheep breeds (P＞0.05). 【Conclusion】 These results implied that the five genes may have some regulatory roles on sheep fertility.

Effects of Different Relative Humidities on Growth Performance, Antioxidant Capacity and Immune Function of Broilers

SUN YongBo,WANG Ya,SA RenNa,ZHANG HongFu

Scientia Agricultura Sinica. 2018, 51(24):  4720-4728.  doi:10.3864/j.issn.0578-1752.2018.24.012

Abstract ( 412 )   HTML ( 41 )   PDF (430KB) ( 260 )   Save

Figures and Tables | References | Related Articles | Metrics

【Objective】 The aim of this study was to investigate the effect of relative humidity on growth performance, antioxidant capacity and immune function of broiler chickens by simulates high, medium and low humidity, and to provide data support for the reasonable regulation of humidity in poultry house, and promote the development of healthy cultivation of broiler chickens. 【Method】 The trial adopted single factor completely random design. A total of 270 healthy AA broilers with similar initial body weight of 1 day old were randomly divided into 3 groups: normal humidity group (control group, 60% RH), low-humidity group (30% RH) and high-humidity group (90% RH), with 6 replications per group and 15 chickens in each replicate. The experiment was conducted in the artificial climate chamber of Changping Base, the State Key Laboratory of Animal Nutrition from February to April in 2006. The cabin was equipped with humidity sensors to continuously monitor the humidity in the cabin for 24 hours, and the humidity was adjusted according to the real-time monitoring values. And the test period was 42d, the starter phase was 1-21 d, and the later phase was 22-42 d. Broilers were reared in flat cages and provided ad libitum access to feed and water, and a 24 h lighting programme was applied during the experiment. They were routinely managed according to the AA broiler feeding manual and immunized according to routine procedures. The growth performance of broiler chickens were measured per pen and blood samples (2 randomly selected from each replicate) were obtained from wing vein of broilers and then slaughtered at 21 and 42 days of age, respectively. The antioxidant capacity, cytokines contents and viscera index of broilers were determined.【Result】 The results showed that: 1) Growth performance: compared to the control group with normal humidity, low-humidity treatment significantly reduced the body weight of 21 and 42 days of age broilers, and significantly reduced average daily gain of broilers (P＜0.05). 2) Antioxidant ability: the serum SOD activity and total antioxidant capacity of broilers in low-humidity group were significantly lower than those in control group at 21 and 42 days of age (P＜0.05). At 42 days of age, the content of malondialdehyde in low-humidity group was significantly higher than that in control group (P＜0.05); total antioxidant capacity in high-humidity group was significantly lower than that of the control group (P＜0.05). 3) Immune function: compared with control group, high-humidity treatment significantly increased the content of inflammatory cytokine IFN-γ and TNF-α in serum of 21 day old broilers (P＜0.05), while the contents of serum cytokines in 42-day-old broilers were not significantly affected by humidity (P＞0.05). 4) Visceral index: the lung index of 42-day-old broilers in the high-humidity group was significantly lower than that in the control group (P＜0.05). In addition, the 42-day-old liver index in the low-humidity group was significantly higher than that in the high-humidity group (P＜0.05). 【Conclusion】 It could be seen that long-term low humidity and high humidity environment reduced the growth performance, antioxidant capacity and immune function of broilers, which was not conducive to the healthy growth of broilers. In the process of broiler breeding, humidification or dehumidification could be used to regulate the humidity in the house in time to promote the healthy growth of broilers.