2022 Vol. 21 No. 5 Previous Issue    Next Issue

    Crop Science
    Plant Protection
    Animal Science · Veterinary Medicine
    Agro-ecosystem & Environment
    Food Science
    Short Communication

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    Biosynthesized metallic nanoparticles as fertilizers: An emerging precision agriculture strategy
    Busiswa NDABA, Ashira ROOPNARAIN, Haripriya RAMA, Malik MAAZA
    2022, 21(5): 1225-1242.  DOI: 10.1016/S2095-3119(21)63751-6
    Abstract ( )   PDF in ScienceDirect  
    Nanofertilizers increase efficiency and sustainability of agricultural crop production.  Due to their nanosize properties, they have been shown to increase productivity through target delivery or slow release of nutrients, thereby limiting the rate of fertilizer application required.  Nanofertilizers can be synthesized via different approaches ranging from physical and chemical to green (biological) synthesis.  The green approach is preferable because it makes use of less chemicals, thereby producing less chemical contamination and it is safer in comparison to physicochemical approaches.  Hence, discussion on the use of green synthesized nanoparticles as nanofertilizers is pertinent for a sustainable approach in agriculture.  This review discusses recent developments and applications of biologically synthesized metallic nanoparticles that can also be used as nanofertilizers, as well as their uptake mechanisms for plant growth.  Toxicity concerns of nanoparticle applications in agriculture are also discussed.
    Crop Science
    TaIAA15 genes regulate plant architecture in wheat
    LI Fu, YAN Dong, GAO Li-feng, LIU Pan, ZHAO Guang-yao, JIA Ji-zeng, REN Zheng-long
    2022, 21(5): 1243-1252.  DOI: 10.1016/S2095-3119(20)63480-3
    Abstract ( )   PDF in ScienceDirect  
    Bread wheat (Triticum aestivum L.) is one of the most important staple crops worldwide.  The phytohormone auxin plays critical roles in the regulation of plant growth and development.  However, only a few auxin-related genes have been genetically demonstrated to be involved in the control of plant architecture in wheat thus far.  In this study, we characterized an auxin-related gene in wheat, TaIAA15, and found that its ectopic expression in rice decreased the plant height and increased the leaf angle.  Correlation analysis indicated that TaIAA15-3B was associated with plant height (Ph), spike length (SL) and 1 000-grain weight (TGW) in wheat, and Hap-II of TaIAA15-3B was the most favored allele and selected by modern breeding in China.  This study sheds light on the role of auxin signaling on wheat plant architecture as well as yield related traits.
    Creation of two hyperactive variants of phytochrome B1 for attenuating shade avoidance syndrome in maize
    ZHAO Yong-ping, ZHAO Bin-bin, WU Guang-xia, MA Xiao-jing, WANG Bao-bao, KONG De-xin, WEI Hong-bin, WANG Hai-yang
    2022, 21(5): 1253-1265.  DOI: 10.1016/S2095-3119(20)63466-9
    Abstract ( )   PDF in ScienceDirect  
    Increasing the planting density of maize is an effective measure to improve its yield.  However, plants under high planting density tend to trigger shade avoidance syndrome (SAS), reducing lodging resistance and ultimately yield drop.  Phytochrome B
    (phyB) plays a dominant role in mediating shade avoidance response.  This study constructed two hyperactive mutated alleles of maize PHYB1: ZmPHYB1Y98F (mimicking Y104F of AtPHYB) and ZmPHYB1Y359F (mimicking Y361F of AtPHYB).  Ectopic expression of ZmPHYB1Y98F and ZmPHYB1Y359F under the control of the ZmPHYB1 promoter in the Arabidopsis phyB-9 background rendered enhanced activity on complementing the phyB-9 related phenotypes compared with ZmPHYB1WT.  Moreover, similar to the behavior of ZmPHYB1WT, ZmPHYB1Y98F and ZmPHYB1Y359F proteins are localized to the nucleus after red light exposure, and could interact with PIF proteins of maize.  In addition, expression of ZmPHYB1Y98F and ZmPHYB1Y359F variants under the control of the native ZmPHYB1 promoter attenuated SAS of maize seedlings subjected to simulated shade treatment.  It effectively reduced mature maize’s plant height and ear height in field conditions.  The results combined demonstrate the utility of ZmPHYB1Y98F and ZmPHYB1Y359F for attenuating SAS and breeding high density-tolerant varieties of maize.

    Dissecting the genetic basis of maize deep-sowing tolerance by combining association mapping and gene expression analysis
    YANG Yue, MA Yu-ting, LIU Yang-yang, Demar LYLE, LI Dong-dong, WANG Ping-xi, XU Jia-liang, ZHEN Si-han, LU Jia-wen, PENG Yun-ling, CUI Yu, FU Jun-jie, DU Wan-li, ZHANG Hong-wei, WANG Jian-hua
    2022, 21(5): 1266-1277.  DOI: 10.1016/S2095-3119(21)63649-3
    Abstract ( )   PDF in ScienceDirect  
    Deep-sowing is an important method for avoiding drought stress in crop species, including maize.  Identifying candidate genes is the groundwork for investigating the molecular mechanism underlying maize deep-sowing tolerance.  This study evaluated four traits (mesocotyl length at 10 and 20 cm planting depths and seedling emergence rate on days 6 and 12) related to deep-sowing tolerance using a large maize population containing 386 inbred lines genotyped with 0.5 million high-quality single nucleotide polymorphisms (SNPs).  The genome-wide association study detected that 273 SNPs were in linkage disequilibrium (LD) with the genetic basis of maize deep-sowing tolerance.  The RNA-sequencing analysis identified 1 944 and 2 098 differentially expressed genes (DEGs) in two comparisons, which shared 281 DEGs.  By comparing the genomic locations of the 273 SNPs with those of the 281 DEGs, we identified seven candidate genes, of which GRMZM2G119769 encoded a sucrose non-fermenting 1 kinase interactor-like protein.  GRMZM2G119769 was selected as the candidate gene because its homologs in other plants were related to organ length, auxin, or light response.  Candidate gene association mapping revealed that natural variations in GRMZM2G119769 were related to phenotypic variations in maize mesocotyl length.  Gene expression of GRMZM2G119769 was higher in deep-sowing tolerant inbred lines.  These results suggest that GRMZM2G119769 is the most likely candidate gene.  This study provides information on the deep-sowing tolerance of maize germplasms and identifies candidate genes, which would be useful for further research on maize deep-sowing tolerance.
    Root characteristics and yield of rice as affected by the cultivation pattern of strong seedlings with increased planting density and reduced nitrogen application
    GUAN Xian-jiao, CHEN Jin, CHEN Xian-mao, XIE Jiang, DENG Guo-qiang, HU Li-zhen, LI Yao, QIAN Yin-fei, QIU Cai-fei, PENG Chun-rui
    2022, 21(5): 1278-1289.  DOI: 10.1016/S2095-3119(20)63595-X
    Abstract ( )   PDF in ScienceDirect  
    To address the relationships between the amount of nitrogen fertilizer application and the yield of double cropping rice systems, we investigated the effects of a cultivation pattern of strong seedlings with increased planting density and reduced nitrogen application (SDN) on the morphological and physiological characteristics of double cropping rice.  Our results indicated that the effects of SDN on the morphological characteristics of the single plant roots of double cropping rice were not significant, but the morphological characteristics of the population roots were largely different.  Specifically, SDN significantly increased the morphological indexes of the root population such as root fresh weight, root volume, root number, root length and root dry weight.  The effects of SDN on the total root absorption areas and root active absorption areas of the single plants were non-significant, but it dramatically enhanced the total root absorption areas and root active absorption areas of the plant population during the tillering, heading and mature stages.  In addition, SDN significantly increased the root bleeding intensity and elevated the soluble sugar and free amino acid contents of root bleeding sap.  Compared to the traditional cultivation pattern (CK), SDN significantly increased root bleeding intensity at the heading stage by 4.37 and 8.90% for early and late rice, respectively.  Meanwhile, SDN profoundly enhanced the soluble sugar contents of root bleeding sap by 12.85 and 10.41% for early and late rice, respectively.  In addition, SDN also significantly enhanced free amino acid content of root bleeding sap by 43.25% for early rice and by 37.50% for late rice systems compared to CK.  Furthermore, SDN increased the actual yield of double cropping rice mainly due to the higher effective panicle number and the larger seed-setting rate.  The actual yields of early rice under SDN were higher than CK by 9.37 and 5.98% in 2016 and 2017, and the actual yields of late rice under SDN were higher than CK by 0.20 and 1.41% in 2016 and 2017, respectively.  Correlation analysis indicated that the significant positive correlations were observed between the majority of the root indexes and the actual yield across the four different growth stages.

    Characteristics of lodging resistance of high-yield winter wheat as affected by nitrogen rate and irrigation managements
    LI Wen-qian, HAN Ming-ming, PANG Dang-wei, CHEN Jin, WANG Yuan-yuan, DONG He-he, CHANG Yong-lan, JIN Min, LUO Yong-li, LI Yong, WANG Zhen-lin
    2022, 21(5): 1290-1309.  DOI: 10.1016/S2095-3119(20)63566-3
    Abstract ( )   PDF in ScienceDirect  
    High yields of wheat are mainly obtained through a high level of nitrogen and irrigation supplementation.  However, excessive nitrogen and irrigation supplication increase the risk of lodging.  The main objectives of this work were to clarify the capacity of lodging resistance of wheat in response to nitrogen and irrigation, as well as to explore the effective ways of improving lodging resistance in a high-yield wheat cultivar. In this study, field experiments were conducted in the 2015–2016 and 2016–2017 growing seasons.  A wheat cultivar Jimai 22 (JM22), which is widely planted in the northern of Huang-Huai winter wheat region, was grown at Tai’an, Shandong Province, under three nitrogen rates and four irrigation treatments.  The lodging risk was increased with increased nitrogen rate, as indicated by increasing lodging index (LI) and lodging rate across both growing seasons.  With nitrogen increasing, the plant height, the basal internode length and the center of gravity height, which were positively correlated with LI, increased significantly.  While the density of the basal 2nd internode (for culm and leaf sheath) and cell wall component contents, which were negatively correlated with LI, decreased conspicuous along with nitrogen increased.  Increasing irrigation supplementation increased the 2nd internode culm wall thickness, breaking strength and leaf sheath density within limits which increased stem strength.  Among the treatments, nitrogen application at a rate of 240 kg ha–1 and irrigation application at 600 m3 ha–1 at both the jointing and anthesis stages resulted in the highest yield and strongest stem.  A suitable plant height ensures sufficient biomass for high yield, and higher stem stiffness, which was primarily attributed to thicker culm wall, greater density of the culm and leaf sheaths and higher cell wall component contents are the characteristics that should be taken into account to improving wheat lodging resistance.

    Predictive models of drought tolerance indices based on physiological, morphological and biochemical markers for the selection of cotton (Gossypium hirsutum L.) varieties
    Yeison M QUEVEDO, Liz P MORENO, Eduardo BARRAGÁN
    2022, 21(5): 1310-1320.  DOI: 10.1016/S2095-3119(20)63596-1
    Abstract ( )   PDF in ScienceDirect  
    The use of tolerant crop varieties is a strategy that mitigates the water deficit effect in a sustainable way.  The generation of these varieties is more efficient when variables associated with this tolerance have been identified, since they can facilitate the breeding processes.  This study aimed to establish the relationships between water deficit tolerance of four cotton varieties (Nevada-123, Oasis-129, Guatapuri, and Festivalle) and morphological variables (monopodial branches, boll weight, root/shoot ratio, and leaf and root dry matter), physiological variables (relative water content, net photosynthesis, stomatal conductance, electron transport rate, photochemical quenching, photochemical efficiency of PSII, chlorophyll a/b ratio (Chl a/b), C12/C13 isotope ratio, and electrolyte leakage), and biochemical variables (contents of sugars, proline, carotenoids, and malondialdehyde).  Furthermore, calibrated predictive models of the drought tolerance indices were developed based on the key variables identified.  For this purpose, a pot experiment was established where plants were subjected to a moderate or severe water deficit during the blooming stage for 12 days.  The stress tolerance index (STI) and mean productivity (MP) were calculated.  For the evaluated variables, the differences between well-watered and water deficit plants (Δ) were calculated and ANOVA, partial least squares, Pearson’s correlation, and multiple linear regression analyzes were performed.  A model was generated that explained 95% of the STI and was composed of Δmalondialdehyde, Δproline, and Δboll weight.  For MP, the model was comprised of Δstomatal conductance, Δroot/shoot ratio, and ΔChl a/b, and explained 89% of the MP.  The analysis of the assessed variables allowed the identification of key variables and the development of calibrated predictive models that can be used in screening to obtain cotton varieties with different levels of water deficit tolerance.
    Genome-wide analysis of OVATE family proteins in cucumber (Cucumis sativus L.)
    HAN Li-jie, SONG Xiao-fei, WANG Zhong-yi, LIU Xiao-feng, YAN Li-ying, HAN De-guo, ZHOU Zhao-yang, ZHANG Xiao-lan
    2022, 21(5): 1321-1331.  DOI: 10.1016/S2095-3119(21)63788-7
    Abstract ( )   PDF in ScienceDirect  
    OVATE family proteins (OFPs) are plant-specific proteins with a conserved OVATE domain that regulate plant growth and development.  Although OFPs have been studied in several species, their biological functions remain largely unknown in cucumber (Cucumis sativus L.).  This study identified 19 CsOFPs distributed on seven chromosomes in cucumber.  Most CsOFP genes were expressed in reproductive organs, but with different expression patterns.  Ectopic expression of CsOFP12-16c in Arabidopsis resulted in shorter and blunt siliques.  The overall results indicated that CsOFP12-16c regulates silique development in Arabidopsis and may have a similar function in cucumber.
    Genome-wide identification of WOX gene family in apple and a functional analysis of MdWOX4b during adventitious root formation
    XU Xiao-zhao, CHE Qin-qin, CHENG Chen-xia, YUAN Yong-bing, WANG Yong-zhang
    2022, 21(5): 1332-1345.  DOI: 10.1016/S2095-3119(21)63768-1
    Abstract ( )   PDF in ScienceDirect  
    The plant-specific WUSCHEL-related homeobox (WOX) genes are crucial for plant growth and development.  Here, we systematically identified the MdWOX gene family in apple at the genome-wide level, and analyzed the phylogenetic relationships, conserved motifs, gene structure, and syntenic relationships of the MdWOX genes.  A total of 18 MdWOX genes were identified and phylogenetic analysis placed them into three clades.  The phylogenetic relationships among the WOXs were further supported by the analyses of gene structure and conserved motifs.  Chromosomal distribution and synteny analysis revealed that whole-genome and segmental duplications have played key roles in MdWOX gene family expansion.  Moreover, the MdWOX genes exhibit tissue-specific expression patterns and MdWOX4a, MdWOX4b, MdWOX5b, MdWOX11/12a, and MdWOX11/12b may play essential roles in adventitious root development.  The adventitious rooting ability was enhanced in MdWOX4b transgenic tobacco lines.  The results of this study provide useful information for future functional studies on MdWOXs in the development of apple rootstocks.  
    Phenotype and mechanism analysis of plant dwarfing in pear regulated by abscisic acid
    LIU Jian-long, ZHANG Chen-xiao, LI Tong-tong, LIANG Cheng-lin, YANG Ying-jie, LI Ding-Li, CUI Zhen-hua, WANG Ran, SONG Jian-kun
    2022, 21(5): 1346-1356.  DOI: 10.1016/S2095-3119(21)63786-3
    Abstract ( )   PDF in ScienceDirect  
    Close planting of dwarf varieties is currently the main cultivation direction for pear trees, and the screening of excellent dwarf varieties is an important goal for breeders.  In this study, the dwarfing pear variety ‘601D’ and its vigorous mutant ‘601T’ were used to show their biological characteristics and further explore the dwarfing mechanism in ‘601D’.  The biological characteristics showed that ‘601D’ had a shorter internode length, a shorter and more compact tree body, thicker and broader leaves, lower stomata density, larger stomata size (dimension), and higher photosynthetic capacity.  The biological characteristics of ‘601T’ showed notable contrasts.  The results of endogenous hormone tests indicated that the contents of abscisic acid (ABA), ABA-glucosyl ester, and GA4 were higher in ‘601D’, but the trans-zeatin content was lower.  By transcriptomic analysis, significant differences were found in the biosynthetic and metabolic pathways of ABA.  Related transcription factors such as bHLH, WRKY, and homeobox also participated in the regulation of plant dwarfing.  We therefore examined three hormones with obvious differences with ‘601T’, and found that only ABA could induce ‘601T’ to return to a dwarfing plant phenotype.  Therefore, we conclude that the dwarfing of ‘601D’ is caused by an excessive accumulation of ABA.  This study provides a new theoretical basis for breeding dwarf varieties.
    Identification of the DEAD-box RNA helicase family members in grapevine reveals that VviDEADRH25a confers tolerance to drought stress
    YANG Sheng-di, GUO Da-long, PEI Mao-song, WEI Tong-lu, LIU Hai-nan, BIAN Lu, YU Ke-ke, ZHANG Guo-hai, YU Yi-he
    2022, 21(5): 1357-1374.  DOI: 10.1016/S2095-3119(21)63870-4
    Abstract ( )   PDF in ScienceDirect  
    Grapevine growing areas are increasingly affected by drought, which has greatly limited global wine production and quality.  DEAD-box is one of the largest subfamilies of the RNA helicase family, and its members play key roles in the growth and development of plants and their stress responses.  Previous studies have shown the potential of DEAD-box genes in the drought stress responses of Arabidopsis and tomato, rice, and other crop species.  However, information about DEAD-box genes in grapevine remains limited.  In this report, a total of 40 DEAD-box genes were identified in grapevine and their protein sequence characteristics and gene structures were analyzed.  By comparing the expression profiles of VviDEADRHs in response to drought stress in different grapevine varieties, nine candidate genes (VviDEADRH10c, -13, -22, -25a, -25b, -33, -34, -36, and -39) were screened based on expression profiling data.  Combined with qRT-PCR results, VviDEADRH25a was selected for functional verification.  Heterologous overexpression of VviDEADRH25a in Arabidopsis showed the transgenic plants were more sensitive to drought stress than the control.  Both electrolyte permeability and malondialdehyde content were significantly increased in transgenic plants, whereas the chlorophyll content and superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX) enzyme activities were significantly decreased.  Furthermore, VviDEADRH25a-overexpressing plants showed down-regulated expression levels of several drought stress-related marker genes, namely AtCOR15a, AtRD29A, AtERD15, and AtP5CS1, which indicated that they participated in the drought stress response.  In summary, this study provides new insights into the structure, evolution, and participation of DEAD-box RNA helicase genes in the response to drought stress in grapevines.

    Plant Protection
    Mutations in FgPrp6 suppressive to the Fgprp4 mutant in Fusarium graminearum
    LI Chao-hui, FAN Zhi-li, HUANG Xin-yi, WANG Qin-hu, JIANG Cong, XU Jin-rong, JIN Qiao-jun
    2022, 21(5): 1375-1388.  DOI: 10.1016/S2095-3119(21)63731-0
    Abstract ( )   PDF in ScienceDirect  
    The pre-mRNA processing factor Prp6 is an essential component of the U4/U6.U5 tri-small nuclear ribonucleoprotein (snRNP).  In a previous study, mutations were identified in the PRP6 ortholog in four suppressors of Fgprp4 that was deleted of the only kinase FgPrp4 among the spliceosome components in the plant pathogenic fungus Fusarium graminearum.  In this study, we identified additional suppressor mutations in FgPrp6 and determined the suppressive effects of selected mutations.  In total, 12 mutations of FgPRP6 were identified in 20 suppressors of Fgprp4 by sequencing analysis.  Whereas three mutation sites are in the linker region of FgPrp6, seven are in the first two HAT repeats.  RNA-seq analysis showed that suppressor mutations on different sites caused different splicing efficiency recovery.  The suppressive effects of E308K and R230H were verified.  Similar to human and fission yeast, the FgPrp6 was phosphorylated by the FgPrp4 kinase.  Interestingly, the conserved Prp4-phosphorylation sites T261, T219&T221, and predicted phosphorylation sites T199&T200 on FgPrp6 were dispensable for the function of FgPrp6 in hyphal growth and sexual reproduction but important in plant infection.  They are required for the infectious growth of F. graminearum in wheat lemma.  RNA-seq analysis of the wheat lemma infected with Fgprp6/FgPRP6Δ199–221-GFP or Fgprp6/FgPRP6Δ250–262-GFP showed that 28 and 35% introns had splicing defects, respectively, which may be responsible for their defects in plant infection.    

    Small RNA deep sequencing reveals the presence of multiple viral infections in cucurbit crops in Guangdong, China
    LI Zheng-gang, NONG Yuan, Tahir FAROOQ, TANG Ya-fei, SHE Xiao-man, YU Lin, LAN Guo-bing, ZHOU Xue-ping, HE Zi-fu
    2022, 21(5): 1389-1400.  DOI: 10.1016/S2095-3119(21)63661-4
    Abstract ( )   PDF in ScienceDirect  
    Viral diseases are among the most critical damaging factors that impose a global threat to the cucurbit industry.  China is the world’s leading country for the production and consumption of cucurbits.  Guangdong, a province in southern China dominated by the tropical and subtropical climate, favors the survival of different plant viruses and their vectors.  Five main cucurbit crops showing various disease symptoms were surveyed and collected to identify viruses infecting cucurbits in Guangdong during 2018–2020.  In the field, the incidence ranged from 5–30%, or even 60–100% in the case of severely infected cucurbits.  A total of 357 symptomatic samples were collected and subsequently screened for cucurbit viruses by small RNA deep sequencing and assembly (sRSA).  Seventeen virus species belonging to 10 genera were identified in the five main cucurbit crops.  The most common viruses were papaya ringspot virus (PRSV; Potyvirus), zucchini tigre mosaic virus (ZTMV; Potyvirus), zucchini yellow mosaic virus (ZYMV; Potyvirus), and watermelon silver mottle virus (WSMoV; Orthotospovirus), with infection rates of 24.4, 19.0, 17.1, and 14.3%, respectively.  Notably, the most prevalent viruses were melon yellow spot orthotospovirus (MYSV) in cucumber, PRSV in squash, cucumber green mottle mosaic virus (CGMMV; Tobamovirus) in bottle gourd, WSMoV in white gourd, and ZYMV in luffa.  Mixed infections were prevalent, and the types of mixed infections varied substantially in different cucurbit crops.  Moreover, the full-length nucleotide sequences of watermelon green mottle mosaic virus (WGMMV), CGMMV, and watermelon virus A (WVA; Wamavirus) identified in bottle gourd were cloned and analyzed.  This study is the first reporting WGMMV infecting bottle gourd in China mainland.  In summary, the results demonstrate that in Guangdong, the most prevalent viruses belong to potyviruses, orthotospoviruses, and tobamoviruses groups.  The findings will facilitate agricultural researchers and farmers to plan and implement effective disease control strategies aiming at timely detection and management of cucurbit-infecting viral pathogens.

    Resistance of barley varieties to Heterodera avenae in the Qinghai–Tibet Plateau, China
    Yan Jia-hui, Jia Jian-ping, JIANG Li-ling, Peng De-liang, Liu Shi-ming, Hou Sheng-ying, YU Jing-wen, Li Hui-xia, Huang Wen-kun
    2022, 21(5): 1401-1413.  DOI: 10.1016/S2095-3119(21)63769-3
    Abstract ( )   PDF in ScienceDirect  
    The cereal cyst nematode, Heterodera avenae, is one of the most economically important pathogens impacting the worldwide production of cereals and is widely distributed in more than 16 regions in China.  The present study used the numbers of nematodes inside the plant roots to evaluate the resistance/susceptibility of different subpopulations of barley Hordeum vulgare (QH2R, QH6R and TB2R) to H. avenae under field and pot conditions.  Nematode development in two highly resistant varieties was also evaluated by in vivo experiment and microscopic observation.  Analyses of 186 selected varieties showed the numbers of susceptible varieties identified with the number of females/cysts per plant (NFP) method were significantly higher than those identified with the Pf/Pi ratio (PPR) method, which indicated that the NFP method rather than the PPR method is more reliable to evaluate the resistance of barley.  The field and pot experiment results indicated that the QH2R subpopulation had lower females/cysts numbers than QH6R and TB2R subpopulations, and eight HR varieties (Sunong 7617, Sunong 7635, Dongyuan 87-14, Rudong 14-46, Rudong 87-57, Rudong 87-8-45, Rudong 88-14-2, and Rudong 88-67-1) were identified in QH2R, with the NFP numbers below 4.2.  Further microscopic observation of nematode development suggested that H. avenae often penetrated less into highly resistant varieties (Sunong 7635 and Dongyuan 87-14) and more frequently failed to develop into females than the susceptible barleys.  The promising resistant varieties identified in the present research might be helpful for breeders to develop CCN-resistant cultivars and control H. avenae populations effectively at low costs.
    Identification and functional characterization of ApisOr23 in pea aphid Acyrthosiphon pisum
    HUANG Tian-yu, ZHANG Rui-bin, YANG Lu-lu, CAO Song, Frederic FRANCIS, WANG Bing, WANG Gui-rong
    2022, 21(5): 1414-1423.  DOI: 10.1016/S2095-3119(20)63577-8
    Abstract ( )   PDF in ScienceDirect  
    Pea aphid, Acyrthosiphon pisum, is a serious pest of many different leguminous plants, and it mainly relies on its odorant receptors (Ors) to discriminate among host species.  However, less is known about the role that Ors play in the host plant location.  In this study, we identified a novel conserved odorant receptor clade by phylogenetic analysis, and conducted the functional analysis of ApisOr23 in A. pisum.  The results showed that the homologous Ors from A. pisum, Aphis glycines and Aphis gossypii share 94.28% identity in amino acid sequences.  Moreover, conserved motifs were analyzed using the annotated homologous Or23 from eight aphid species, providing further proof of the high conservation level of the Or23 clade.  According to the tissue expression pattern analysis, ApisOr23 was mainly expressed in the antennae.  Further functional study using a heterologous Xenopus expression system revealed that ApisOr23 was tuned to five plant volatiles, namely trans-2-hexen-1-al, cis-2-hexen-1-ol, 1-heptanol, 4´-ethylacetophenone, and hexyl acetate.  Among them, trans-2-hexen-1-al, which is one of the main volatile organic compounds released from legume plants, activated the highest response of ApisOr23.  Our findings suggest that the conserved Or23 clade in most aphid species might play an important role in host plant detection.

    Assessment of the potential toxicity of insecticidal compounds to Peristenus spretus, a parasitoid of mirid bugs
    ZHAO Man, LI Yun-he, NIU Lin-lin, CHEN Lin, LIANG Ge-mei
    2022, 21(5): 1424-1435.  DOI: 10.1016/S2095-3119(20)63597-3
    Abstract ( )   PDF in ScienceDirect  
    With the increased cultivation of Bt crops in China, Apolygus lucorum and other mirid bugs have emerged as important agricultural pests because they are insensitive to the Bt proteins.  In addition, the reduction of pesticide applications after planting Bt crops also increases the severity of mirid bug outbreaks.  Peristenus spretus is a parasitoid of mirid nymphs, but its sensitivity to Bt proteins is not known.  In the current study, we developed a dietary exposure assay to assess the effects of Bt proteins (Cry1Ab, Cry1Ac, Cry1F, Cry2Aa, and Cry2Ab) on P. spretus adults using a diet consisting of a 10% honey solution with or without Bt proteins at 400 µg g–1 diet.  The results showed that the survival and reproduction of P. spretus adults were reduced by the cysteine protease inhibitor E-64 (a positive control) but were not affected by any of the five Bt proteins.  The activities of digestive, detoxifying, and antioxidant enzymes in P. spretus were also unaffected by diets containing the Cry proteins, but they were significantly affected by the diet containing E-64.  We then developed a tri-trophic bioassay to determine the effects of the five Bt proteins on P. spretus larvae and pupae.  In this assay, A. lucorum nymphs fed an artificial diet containing Cry proteins were used as the hosts for P. spretus.  The results of the tri-trophic assay indicated that neither the pupation rate nor the eclosion rate of the P. spretus parasitoids were significantly affected by the presence of high concentrations of Bt proteins in the parasitized A. lucorum nymphs.  The overall results indicate that these two assays can be used to evaluate the toxicity of insecticidal compounds to P. spretus and that the tested Cry proteins are not toxic to P. spretus.  
    Genetics and fitness costs of resistance to flupyradifurone in Bemisia tabaci from China
    WANG Ran, ZHANG Jia-song, CHE Wu-nan, WANG Jin-da, LUO Chen
    2022, 21(5): 1436-1443.  DOI: 10.1016/S2095-3119(20)63500-6
    Abstract ( )   PDF in ScienceDirect  
    Flupyradifurone is a promising new insecticide used for controlling Bemisia tabaci during vegetable production.  In this study, we assessed the fitness costs and mode of inheritance associated with resistance to flupyradifurone in B. tabaci by comparing the susceptible strain (MED-S) to one field-evolved flupyradifurone-resistant strain (WH-R, with 199-fold resistance) and one laboratory-selected flupyradifurone-resistant strain (FLU-SEL, with 124-fold resistance).  Progenies of reciprocal crosses between WH-R and MED-S (F1A, F1B, and pooled F1), and between FLU-SEL and MED-S (F1C, F1D, and pooled F1’), showed varying degrees of dominance, indicating that resistance to flupyradifurone in WH-R was autosomal and incompletely dominant, yet in FLU-SEL it was autosomal and incompletely recessive.  Furthermore, the development of resistance to flupyradifurone occurred at the expense of fitness costs for the resistant populations.  Compared to the MED-S strain, WH-R showed a relative fitness of 0.50 with significantly prolonged developmental durations and reduced survival rates of the nymphal and pseudopupal stages, as well as decreased fecundity and hatchability.  Similarly, FLU-SEL showed a relative fitness of 0.65 and also demonstrated prolonged developmental durations and reduced survival rates of nymphs and pseudopupae, as well as decreased hatchability in comparison with the MED-S strain.  However, no significant differences in fecundity were observed between MED-S and FLU-SEL.  The present study provides useful knowledge for formulating pest management strategies in the field, which will allow growers to slow the development of resistance to flupyradifurone and to sustainably control B. tabaci.

    Animal Science · Veterinary Medicine
    The expression, function, and coding potential of circular RNA circEDC3 in chicken skeletal muscle development
    WEI Yuan-hang, ZHAO Xi-yu, SHEN Xiao-xu, YE Lin, ZHANG Yao, WANG Yan, LI Di-yan, ZHU Qing, YIN Hua-dong
    2022, 21(5): 1444-1456.  DOI: 10.1016/S2095-3119(21)63826-1
    Abstract ( )   PDF in ScienceDirect  
    As an emerging class of non-coding transcripts, circular RNAs (circRNAs) are proved to participate in the complex process of myogenesis in diverse species.  A previous study has identified circular RNA EDC3 (circEDC3) as a typical covalently closed circular RNA abundant in chicken skeletal muscle.  This study found that circEDC3 is a conservative circular RNA and performed functional analysis to investigate the role of circEDC3 in chicken muscle growth.  The results indicated that circEDC3 could inhibit (P<0.05) chicken skeletal muscle satellite cells (SMSCs) proliferation and differentiation but had no significant influence on SMSCs apoptosis.  Additionally, bioinformatics analysis showed that circEDC3 had promising coding potential.  The open reading frames (ORF) were found in circEDC3 in this study.  Furthermore, this study predicted that circEDC3 had internal ribosome entry sites (IRES) and N6-methyladenosine (m6A) motifs in different species, implying that circEDC3 might be translatable.  This study revealed that circEDC3 might be a negative regulator in chicken muscle development and suggested it has protein-coding potential in different species.
    Integrative analysis of hypothalamic transcriptome and genetic association study reveals key genes involved in the regulation of egg production in indigenous chickens
    WANG Dan-dan, ZHANG Yan-yan, TENG Meng-lin, WANG Zhang, XU Chun-lin, JIANG Ke-ren, MA Zheng, LI Zhuan-jian, TIAN Ya-dong, Kang Xiang-tao, LI Hong, LIU Xiao-jun
    2022, 21(5): 1457-1474.  DOI: 10.1016/S2095-3119(21)63842-X
    Abstract ( )   PDF in ScienceDirect  
    Indigenous chicken products are increasingly favored by consumers due to their unique meat and egg quality.  However, the relatively poor egg-laying performance largely impacts the economic benefits and hinders sustainable development of the local chicken industry.  Thus, excavating key genes and effective molecular markers associated with egg-laying performance is necessary to improve egg production via genetic selection in indigenous breeds.  In the present study, comparative hypothalamic transcriptome between pre-laying (15 weeks old) and peak-laying (30 weeks old) Lushi blue-shelled-egg (LBS) chicken was performed.  A total of 518 differentially expressed genes (DEGs) were identified.  Among the DEGs, 64 genes were enriched in 10 Gene Ontology (GO) terms associated with reproductive regulation via GO analysis and considered as potential candidate genes regulating egg-laying performance.  Of the 64 genes, 16 showed high connectivity (degree≥12) by protein–protein interaction (PPI) network analysis and were considered as potential core candidate genes (PCCGs).  To further look for key candidate genes from the PCCGs, firstly, the expression patterns of the 16 genes were examined in the hypothalamus of two indigenous breeds (LBS and Gushi (GS) chickens) between the pre-laying and peak-laying stages using quantitative real-time PCR (qRT-PCR).  Eleven out of the 16 genes showed significantly differential expression (P<0.05) with the same changing trends in the two breeds.  Then, correlations between the expression levels of the above 11 genes and egg numbers and reproductive hormone concentrations in serum were investigated in high-yielding and low-yielding GS chickens.  Of the 11 genes, eight showed significant correlations (P<0.05) between their expression levels and egg numbers, and between expression levels and reproductive hormone concentration in serum.  Furthermore, an association study on single nucleotide polymorphisms (SNPs) identified in these eight genes and egg production traits was carried out in 640 GS hens, and a significant association (P<0.05) between the SNPs and egg numbers was confirmed.  In conclusion, the eight genes, including CNR1, AP2M1, NRXN1, ANXA5, PENK, SLC1A2, SNAP25 and TRH, were demonstrated as key genes regulating egg production in indigenous chickens, and the SNPs sites within the genes might be served as markers to provide a guide for indigenous chicken breeding.  These findings provide a novel insight for further understanding the regulatory mechanisms of egg-laying performance and developing molecular markers to improve egg production of indigenous breeds.
    Agro-ecosystem & Environment
    Estimation of soil organic carbon stock and its controlling factors in cropland of Yunnan Province, China
    SUN Tao, TONG Wen-jie, CHANG Nai-jie, DENG Ai-xing, LIN Zhong-long, FENG Xing-bing, LI Jun-ying, SONG Zhen-wei
    2022, 21(5): 1475-1487.  DOI: 10.1016/S2095-3119(21)63620-1
    Abstract ( )   PDF in ScienceDirect  
    Soil organic carbon (SOC) is the most important indicators of soil quality and health.  Identifying the spatial distribution of SOC and its influencing factors in cropland is crucial to understand the terrestrial carbon cycle and optimize agronomic management.  Yunnan Province, characterized by mountainous topography and varied elevation, is one of the highest SOC regions in China.  Yet its SOC stock of cropland and influencing factors has not been fully studied due to the lack of adequate soil investigation.  In this study, the digital mapping of SOC at 1 km resolution and the estimation of total SOC stock in cropland of Yunnan Province was undertaken using 8 637 topsoil (0–20 cm) samples and a series of spatial data through Random Forest (RF) model.  It was showed that across the cropland of Yunnan Province, the mean SOC density and total stock were 4.84 kg m–2 and 337.5 Mt, respectively.  The spatial distribution indicated that relatively high SOC density regions resided in the northwest and northeast parts of Yunnan Province.  Elevation (19.5%), temperature (17.3%), rainfall (14.5%), and Topographic wetness index (9.9%) were the most important factors which controlled spatial variability of SOC density.  Agronomic practices (e.g., crop straw treatments, fertilizer management) should be optimized for the sustainable development of crop production with high SOC sequestration capacity in Yunnan Province.
    Increasing soil microbial biomass nitrogen in crop rotation systems by improving nitrogen resources under nitrogen application
    XING Ting-ting, CAI An-dong, LU Chang-ai, YE Hong-ling, WU Hong-liang, HUAI Sheng-chang, WANG Jin-yu, XU Ming-gang, LIN Qi-mei
    2022, 21(5): 1488-1500.  DOI: 10.1016/S2095-3119(21)63673-0
    Abstract ( )   PDF in ScienceDirect  
    Soil microbial biomass nitrogen (MBN) contains the largest proportion of biologically active nitrogen (N) in soil, and is considered as a crucial participant in soil N cycling.  Agronomic management practices such as crop rotation and mono-cropping systems, dramatically affect MBN in agroecosystems.  However, the influence of crop rotation and mono-cropping in agroecosystems on MBN remains unclear.  A meta-analysis based on 203 published studies was conducted to quantify the effect of crop rotation and mono-cropping systems on MBN under synthetic N fertilizer application.  The analysis showed that crop rotation significantly stimulated the response ratio (RR) of MBN to N fertilization and this parameter reached the highest levels in upland-fallow rotations.  Upland mono-cropping did not change the RR of MBN to N application, however, the RR of MBN to N application in paddy mono-cropping increased.  The difference between crop rotation and mono-cropping systems appeared to be due to the various cropping management scenarios, and the pattern, rate and duration of N addition.  Crop rotation systems led to a more positive effect on soil total N (TN) and a smaller reduction in soil pH than mono-cropping systems.  The RR of MBN to N application was positively correlated with the RR of mineral N only in crop rotation systems and with the RR of soil pH only in mono-cropping systems.  Combining the results of Random Forest (RF) model and structural equation model showed that the predominant driving factors of MBN changes in crop rotation systems were soil mineral N and TN, while in mono-cropping systems the main driving factor was soil pH.  Overall, our study indicates that crop rotation can be an effective way to enhance MBN by improving soil N resources, which promote the resistance of MBN to low pH induced by intensive synthetic N fertilizer application.

    The Nutrient Expert decision support system improves nutrient use efficiency and environmental performance of radish in North China
    ZHANG Jia-jia, DING Wen-cheng, CUI Rong-zong, LI Ming-yue, Sami ULLAH, HE Ping
    2022, 21(5): 1501-1512.  DOI: 10.1016/S2095-3119(21)63660-2
    Abstract ( )   PDF in ScienceDirect  
    Excessive fertilization has led to nutrient use inefficiency and serious environmental consequences for radish cultivation in North China.  The Nutrient Expert (NE) system is a science-based, site-specific fertilization decision support system, but the updated NE system for radish has rarely been evaluated.  This study aims to validate the feasibility of NE for radish fertilization management from agronomic, economic, and environmental perspectives.  A total of 46 field experiments were conducted over four seasons from April 2018 to November 2019 across the major radish growing regions in North China.  The results indicated that NE significantly reduced N, P2O5, and K2O application rates by 98, 110, and 47 kg ha−1 relative to those in the farmers’ practice (FP), respectively, and reduced N and P2O5 inputs by 48 and 44 kg ha−1, respectively, while maintaining the same K2O rate as soil testing (ST).  Relative to FP and ST, NE significantly increased radish yield by 2.7 and 2.6 t ha−1 (4.2 and 4.0%) and net returns by 837 and 432 USD ha−1, respectively.  On average, NE significantly improved the agronomic efficiency (AE) of N, P, and K (relative to FP and ST) by 42.4 and 31.0, 67.4 kg kg−1 and 50.9, and 20.3 and 12.3 kg kg−1; enhanced the recovery efficiency (RE) of N, P, and K by 11.4 and 7.0, 14.1 and 7.5, and 11.3 and 6.3 percentage points; and increased the partial factor productivity (PFP) of N, P, and K by 162.9 and 96.8, 488.0 and 327.3, and 86.9 and 22.4 kg kg−1, respectively.  Furthermore, NE substantially reduced N and P2O5 surpluses by 105.1 and 115.1 kg ha−1, respectively, and decreased apparent N loss by 110.8 kg ha−1 compared to FP.  These results indicated that the NE system is an effective and feasible approach for improving NUE and promoting cleaner radish production in North China.

    Food Science
    Comparison of structural and physicochemical properties of potato protein and potato flour modified with tyrosinase
    ZHU Yu, YUAN Yu-han, MEI Li-ping, DING Shuang-kun, GAO Yu-chen, DU Xian-feng, GUO Li
    2022, 21(5): 1513-1524.  DOI: 10.1016/S2095-3119(21)63852-2
    Abstract ( )   PDF in ScienceDirect  
    The present study modified potato protein and flour with tyrosinase to promote the diversification of potato staple foods.  The results indicated that tyrosinase treatment markedly altered the secondary structure of proteins.  After tyrosinase treatment, the maximum decomposition temperature of potato protein and flour increased from 322.32 to 332.40°C and from 294.24 to 299.61°C, respectively.  Tyrosinase treatment remarkably reduced the pasting viscosity of potato flour, that is, the peak viscosity, through reducing viscosity, breakdown, final viscosity, and setback by 32.50, 60.98, 13.04, 68.24, and 74.31%, respectively.  In contrast, tyrosinase treatment increased the shear resistance and hardness of the protein and flour gels; the maximum stress values of the protein and flour gels increased from 1.48 to 10.1% and from 6.87 to 14.8%, respectively.  Furthermore, tyrosinase treatment promoted viscoelastic properties and structural stability of potato protein and flour.  These results may provide an important foundation for the development of novel potato staple foods.

    Sodium dehydroacetate treatment prolongs the shelf-life of ‘Kyoho’ grape by regulating oxidative stress and DNA methylation
    GUO Da-long, LIU Hai-nan, WANG Zhen-guang, GUO Li-li, ZHANG Guo-hai
    2022, 21(5): 1525-1533.  DOI: 10.1016/S2095-3119(21)63765-6
    Abstract ( )   PDF in ScienceDirect  
    In this study, we tested the ability of sodium dehydroacetate (SD) to extend the shelf-life of ‘Kyoho’ grape.  Among the different concentrations of SD tested (0, 0.01, 0.1 and 1.0 mmol L–1), 0.01 mmol L–1 SD was the most effective in prolonging the shelf-life of ‘Kyoho’ grape.  Compared with the control, the weight loss rate, browning index and hydrogen peroxide (H2O2) and malonaldehyde contents were significantly lower in the 0.01 mmol L–1 SD treatment, whereas the healthy berry rate, berry firmness, total soluble solids (TSS) content, ascorbic acid content and superoxide dismutase (SOD) activity were significantly higher.  In addition, an analysis of ‘Kyoho’ grape DNA using methylation sensitive amplification polymorphism (MSAP) markers showed that the average DNA methylation level was significantly higher in the 0.01 mmol L–1 SD treatment than in the control.  Together, these results indicate that 0.01 mmol L–1 SD could be used to extend the shelf-life of ‘Kyoho’ grape.  Moreover, a strong connection between reactive oxygen species (ROS) metabolism and DNA methylation change during storage was revealed.
    Short Communication
    Emergence of H5N1 highly pathogenic avian influenza in Democratic People’s Republic of Korea
    LIU Li-ling, YANG Huan-liang, GUO Fu-sheng, WANG Xiu-rong, DENG Guo-hua, SHI Jian-zhong, TIAN Guo-bin, ZENG Xian-ying
    2022, 21(5): 1534-1538.  DOI: 10.1016/S2095-3119(21)63829-7
    Abstract ( )   PDF in ScienceDirect  
    In the past decade, there has been extensive global surveillance for highly pathogenic avian influenza (HPAI) infection in both animals and humans, however, few studies on epidemiology of avian influenza in Democratic People’s Republic of Korea (DPRK) were published.  During the period 2013–2014, HPAI H5N1 viruses were detected with outbreaks in domestic poultry in DPRK.  Phylogenetic analysis revealed that the hemagglutinin gene of all samples belonged to clade with high homology.  The HPAI H5N1 virus found in ducks at the Tudan Duck Farm in 2013 was might introduced by migratory birds and then led to the outbreaks on neighboring chicken farms in 2014.  These data provide direct evidence for the transmission of avian influenza viruses from wild birds to waterfowl to terrestrial birds.  Therefore, the monitoring and control of influenza virus in ducks must be given top priority, which are essential components to prevent and control HPAI.