2023 Vol. 22 No. 9 Previous Issue   
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Crop Science
Dissecting the key genomic regions underlying high yield potential in common wheat variety ‘Kenong 9204’
ZHAO Chun-hua, ZHANG Na, FAN Xiao-li, JI Jun, SHI Xiao-li, CUI Fa, LING Hong-qing, LI Jun-ming
2023, 22(9): 2603-2616.  DOI: 10.1016/j.jia.2023.02.013
Abstract ( )   PDF in ScienceDirect  
The foundation parents play key roles in the genetic improvement of both yield potential and end-use quality in wheat.  Characterizing the genetic basis that underlies certain beneficial traits in the foundation parents will provide theoretical reference for molecular breeding by a design approach.  ‘Kenong 9204’ (KN9204) is a candidate foundation parent characterized by ideotype, high yield potential, and particularly high nitrogen fertilizer utilization.  To better understand the genetic basis of its high yield potential, high throughput whole-genome re-sequencing (10×) was performed on KN9204, its parental lines and its derivatives.  A high-resolution genetic composition map of KN9204 was constructed, which showed the parental origin of the favorable genomic segments based on the identification of excellent yield-related quantitative trait loci (QTL) from a bi-parental mapping population.  Xiaoyan 693 (XY693), a wheat–Thinopyrum ponticum partial amphidiploid, contributed a great deal to the high yield potential of KN9204, and three major stable QTLs from XY693 were fine mapped.  The transmissibility of key genomic segments from KN9204 to its derivatives were delineated, indicating that haplotype blocks containing beneficial gene combinations were conserved along with directional selection by breeders.  Evidence for selection sweeps in the breeding programs was identified.  This study provides a theoretical reference for the breeding of high-yield wheat varieties by a molecular design approach.
Dissecting the genetic basis of grain color and pre-harvest sprouting resistance in common wheat by association analysis
YAN Sheng-nan, YU Zhao-yu, GAO Wei, WANG Xu-yang, CAO Jia-jia, LU Jie, MA Chuan-xi, CHANG Cheng, ZHANG Hai-ping
2023, 22(9): 2617-2631.  DOI: 10.1016/j.jia.2023.04.017
Abstract ( )   PDF in ScienceDirect  
Pre-harvest sprouting (PHS) adversely affects wheat quality and yield, and grain color (GC) is associated with PHS resistance.  However, the genetic relationship between GC and PHS resistance remains unclear.  In this study, 168 wheat varieties (lines) with significant differences in GC and PHS resistance were genotyped using an Illumina 90K iSelect SNP array.  Genome-wide association study (GWAS) based on a mixed linear model showed that 67 marker-trait associations (MTAs) assigned to 29 loci, including 17 potentially novel loci, were significantly associated with GC, which explained 1.1–17.0% of the phenotypic variation.  In addition, 100 MTAs belonging to 54 loci, including 31 novel loci, were significantly associated with PHS resistance, which accounted for 1.1–14.7% of the phenotypic variation.  Subsequently, two cleaved amplified polymorphic sequences (CAPS) markers, 2B-448 on chromosome 2B and 5B-301 on chromosome 5B, were developed from the representative SNPs of the major common loci Qgc.ahau-2B.3/Qphs.ahau-2B.4 controlling GC/PHS resistance and PHS resistance locus Qphs.ahau-5B.4, respectively.  Further validation in 171 Chinese mini-core collections confirmed significant correlations of the two CAPS markers with GC and PHS resistance phenotypes under different environments (P<0.05).  Furthermore, the wheat public expression database, transcriptomic sequencing, and gene allelic variation analysis identified TraesCS5B02G545100, which encodes glutaredoxin, as a potential candidate gene linked to Qphs.ahau-5B.4.  The new CAPS marker CAPS-356 was then developed based on the SNP (T/C) in the coding sequences (CDS) region of TraesCS5B02G545100.  The high-density linkage map of the Jing 411/Hongmangchun 21 recombinant inbred lines (RILs) constructed based on specific locus amplified fragment sequencing markers showed that CAPS-356 collocated with a novel QTL for PHS resistance, supporting the role of TraesCS5B02G545100 as the potential candidate gene linked to Qphs.ahau-5B.4.  These results provide valuable information for the map-based cloning of Qphs.ahau-5B.4 and breeding of PHS resistant white-grained varieties.
Natural variations and geographical distributions of seed carotenoids and chlorophylls in 1 167 Chinese soybean accessions
Berhane S. GEBREGZIABHER, ZHANG Sheng-rui, Muhammad AZAM, QI Jie, Kwadwo G. AGYENIM-BOATENG, FENG Yue, LIU Yi-tian, LI Jing, LI Bin, SUN Jun-ming
2023, 22(9): 2632-2647.  DOI: 10.1016/j.jia.2022.10.011
Abstract ( )   PDF in ScienceDirect  
Understanding the composition and contents of carotenoids in various soybean seed accessions is important for their nutritional assessment.  This study investigated the variability in the concentrations of carotenoids and chlorophylls and revealed their associations with other nutritional quality traits in a genetically diverse set of Chinese soybean accessions comprised of cultivars and landraces.  Genotype, planting year, accession type, seed cotyledon color, and ecoregion of origin significantly influenced the accumulation of carotenoids and chlorophylls.  The mean total carotenoid content was in the range of 8.15–14.72 µg g–1 across the ecoregions.  The total carotenoid content was 1.2-fold higher in the landraces than in the cultivars.  Soybeans with green cotyledons had higher contents of carotenoids and chlorophylls than those with yellow cotyledons.  Remarkably, lutein was the most abundant carotenoid in all the germplasms, ranging from 1.35–37.44 µg g–1.  Carotenoids and chlorophylls showed significant correlations with other quality traits, which will help to set breeding strategies for enhancing soybean carotenoids without affecting the other components.  Collectively, our results demonstrate that carotenoids are adequately accumulated in soybean seeds, however, they are strongly influenced by genetic factors, accession type, and germplasm origin.  We identified novel germplasms with the highest total carotenoid contents across the various ecoregions of China that could serve as the genetic materials for soybean carotenoid breeding programs, and thereby as the raw materials for food sectors, pharmaceuticals, and the cosmetic industry.
Construction of SNP genetic maps based on targeted next-generation sequencing and QTL mapping of vital agronomic traits in faba bean (Vicia faba L.)
LI Meng-wei, HE Yu-hua, LIU Rong, LI Guan, WANG Dong, JI Yi-shan, YAN Xin, HUANG Shu-xian, WANG Chen-yu, MA Yu, LIU Bei, YANG Tao, ZONG Xu-xiao
2023, 22(9): 2648-2659.  DOI: 10.1016/j.jia.2023.01.003
Abstract ( )   PDF in ScienceDirect  
Owing to the limitation of a large genome size (~13 Gb), the genetic and gene mapping studies on faba bean (Vicia faba L.) are lagging far behind those for other legumes.  In this study, we selected three purified faba bean lines (Yundou 8137, H0003712, and H000572) as parents and constructed two F2 populations.  These two F2 populations, namely 167 F2 plants in Pop1 (Yundou 8137×H0003712) and 204 F2 plants in Pop2 (H000572×Yundou 8137), were genotyped using a targeted next-generation sequencing (TNGS) genotyping platform, and two high-density single nucleotide polymorphisms (SNP) genetic linkage maps of faba bean were constructed.  The map constructed from Pop1 contained 5 103 SNPs with a length of 1 333.31 cM and an average marker density of 0.26 cM.  The map constructed from Pop2 contained 1 904 SNPs with a greater length of 1 610.61 cM.  In these two F2 populations, QTL mapping identified 98 QTLs for 14 agronomic traits related to the flowers, pods, plant types and grains.  The two maps were then merged into an integrated genetic linkage map containing 6 895 SNPs, with a length of 3 324.48 cM.  These results not only lay the foundation for fine mapping and map-based cloning of related genes, but can also accelerate the molecular marker-assisted breeding of faba bean.
Combining nitrogen effects and metabolomics to reveal the response mechanisms to nitrogen stress and the potential for nitrogen reduction in maize
LU Yan-li, SONG Gui-pei, WANG Yu-hong, WANG Luo-bin, XU Meng-ze, ZHOU Li-ping, WANG Lei
2023, 22(9): 2660-2672.  DOI: 10.1016/j.jia.2023.03.002
Abstract ( )   PDF in ScienceDirect  

The physiological and metabolic differences in maize under different nitrogen (N) levels are the basis of reasonable N management, which is vital in improving fertilizer utilization and reducing environmental pollution.  In this paper, on the premise of defining the N fertilizer efficiency and yield under different long-term N fertilization treatments, the corresponding differential metabolites and their metabolic pathways were analyzed by untargeted metabolomics in maize.  N stress, including deficiency and excess, affects the balance of carbon (C) metabolism and N metabolism by regulating C metabolites (sugar alcohols and tricarboxylic acid (TCA) cycle intermediates) and N metabolites (various amino acids and their derivatives).  L-alanine, L-phenylalanine, L-histidine, and L-glutamine decreased under N deficiency, and L-valine, proline, and L-histidine increased under N excess.  In addition to sugar alcohols and the above amino acids in C and N metabolism, differential secondary metabolites, flavonoids (e.g., kaempferol, luteolin, rutin, and diosmetin), and hormones (e.g., indoleacetic acid, trans-zeatin, and jasmonic acid) were initially considered as indicators for N stress diagnosis under this experimental conditions.  This study also indicated that the leaf metabolic levels of N2 (120 kg ha–1 N) and N3 (180 kg ha–1 N) were similar, consistent with the differences in their physiological indexes and yields over 12 years.  This study verified the feasibility of reducing N fertilization from 180 kg ha–1 (locally recommended) to 120 kg ha–1 at the metabolic level, which provided a mechanistic basis for reducing N fertilization without reducing yield, further improving the N utilization rate and protecting the ecological environment.

Integrating microRNAs and mRNAs reveals the hormones synthesis and signal transduction of maize under different N rates
YUE Kai, LI Ling-ling, XIE Jun-hong, Zechariah EFFAH, Sumera ANWAR, WANG Lin-lin, MENG Hao-feng, LI Lin-zhi
2023, 22(9): 2673-2686.  DOI: 10.1016/j.jia.2023.02.016
Abstract ( )   PDF in ScienceDirect  
The effect of nitrogen (N) fertilizer on the development of maize kernels has yet to be fully explored.  MicroRNA-mRNA analyses could help advance our understanding of how kernels respond to N.  This study analyzed the morphological, physiological, and transcriptomic changes in maize kernels under different N rates (0, 100, 200, and 300 kg ha–1).  The result showed that increasing N application significantly increased maize grains’ fresh and dry weight until N reached 200 kg ha–1.  Higher levels of indole-3-acetic acid, cytokinin, gibberellin, and a lower level of ethylene were associated with increased N applications.  We obtained 31 differentially expressed genes (DEGs) in hormone synthesis and transduction, and 9 DEGs were regulated by 14 differentially expressed microRNAs (DEMIs) in 26 pairs.  The candidate DEGs and DEMIs provide valuable insight for manipulating grain filling under different N rates.
The PcERF5 promotes anthocyanin biosynthesis in red-fleshed pear (Pyrus communis) through both activating and interacting with PcMYB transcription factors
CHANG Yao-jun, CHEN Guo-song, YANG Guang-yan, SUN Cong-rui, WEI Wei-lin, Schuyler S. KORBAN, WU Jun
2023, 22(9): 2687-2704.  DOI: 10.1016/j.jia.2023.07.007
Abstract ( )   PDF in ScienceDirect  

As there is a strong interest in red-skinned pears, the molecular mechanism of anthocyanin regulation in red-skinned pears has been widely investigated; however, little is known about the molecular mechanism of anthocyanin regulation in red-fleshed pears due to limited availability of such germplasm, primarily found in European pears (Pyrus communis).  In this study, based on transcriptomic analysis in red-fleshed and white-fleshed pears, we identified an ethylene response factor (ERF) from Pcommunis, PcERF5, of which expression level in fruit flesh was significantly correlated with anthocyanin content.  We then verified the function of PcERF5 in regulating anthocyanin accumulation by genetic transformation in both pear skin and apple calli.  PcERF5 regulated anthocyanin biosynthesis by different regulatory pathways.  On the one hand, PcERF5 can activate the transcription of flavonoid biosynthetic genes (PcDFR, PcANS and PcUFGT) and two key transcription factors encoding genes PcMYB10 and PcMYB114.  On the other hand, PcERF5 interacted with PcMYB10 to form the ERF5-MYB10 protein complex that enhanced the transcriptional activation of PcERF5 on its target genes.  Our results suggested that PcERF5 functioned as a transcriptional activator in regulating anthocyanin biosynthesis, which provides new insights into the regulatory mechanism of anthocyanin biosynthesis.  This new knowledge will provide guidance for molecular breeding of red-fleshed pear.

Comparison of cell wall changes of two different types of apple cultivars during fruit development and ripening
LI Xiang-lu, SU Qiu-fang, JIA Rong-jian, WANG Zi-dun, FU Jiang-hong, GUO Jian-hua, YANG Hui-juan, ZHAO Zheng-yang
2023, 22(9): 2705-2718.  DOI: 10.1016/j.jia.2023.07.019
Abstract ( )   PDF in ScienceDirect  

Fruit development and ripening is a complex procedure (Malus×domestica Borkh.) and can be caused by various factors such as cell structure, cell wall components, and cell wall hydrolytic enzymes.  In our study, we focused on the variations in fruit firmness, cell wall morphology and components, the activity of cell wall hydrolytic enzymes and the expression patterns of associated genes during fruit development in two different types of apple cultivars, the hard-crisp cultivar and the loose-crisp cultivar.  In this paper, the aim was to find out the causes of the texture variations between the different type cultivars.  Cell wall materials (CWMs), hemicellulose and cellulose content were strongly associated with variations in fruit firmness during the fruit development.  The content of water soluble pectin (WSP) and chelator soluble pectin (CSP) gradually increased, while the content of ionic soluble pectin (ISP) showed inconsistent trends in the four cultivars.  The activities of polygalacturonase (PG), β-galactosidase (β-gal), cellulase (CEL), and pectate lyase (PL) gradually increased in four cultivars.  And the activities of PG, β-gal, and CEL were higher in ‘Fuji’ and ‘Honeycrisp’ fruit with the fruit development, while the activity of PL of ‘Fuji’ and ‘Honeycrisp’ was lower than that of ‘ENVY’ and ‘Modi’.  Both four cultivars of fruit cells progressively became bigger as the fruit expanded, with looser cell arrangements and larger cell gaps.  According to the qRT-PCR, the relative expression levels of MdACO and Mdβ-gal were notably enhanced.  Our study showed that there were large differences in the content of ISP and hemicellulose, the activity of PL and the relative expression of Mdβ-gal between two different types of apple cultivars, and these differences might be responsible for the variations in the texture of the four cultivars.

Core collection construction of tea plant germplasm in Anhui Province based on genetic diversity analysis using simple sequence repeat markers
TAO Ling-ling, TING Yu-jie, CHEN Hong-rong, WEN Hui-lin, XIE Hui, LUO Ling-yao, HUANG Ke-lin, ZHU Jun-yan, LIU Sheng-rui, WEI Chao-ling
2023, 22(9): 2719-2728.  DOI: 10.1016/j.jia.2023.07.020
Abstract ( )   PDF in ScienceDirect  

The tea plant [Camellia sinensis (L.) O. Kuntze] is an industrial crop in China.  The Anhui Province has a long history of tea cultivation and has a large resource of tea germplasm with abundant genetic diversity.  To reduce the cost of conservation and utilization of germplasm resources, a core collection needs to be constructed.  To this end, 573 representative tea accessions were collected from six major tea-producing areas in Anhui Province.  Based on 60 pairs of simple sequence repeat (SSR) markers, phylogenetic relationships, population structure and principal coordinate analysis (PCoA) were conducted.  Phylogenetic analysis indicated that the 573 tea individuals clustered into five groups were related to geographical location and were consistent with the results of the PCoA.  Finally, we constructed a core collection consisting of 115 tea individuals, accounting for 20% of the whole collection.  The 115 core collections were considered to have a 90.9% retention rate for the observed number of alleles (Na), and Shannon’s information index (I) of the core and whole collections were highly consistent.  Of these, 39 individuals were preserved in the Huangshan area, accounting for 33.9% of the core collection, while only 10 individuals were reserved in the Jinzhai County, accounting for 8.9% of the core set.  PCoA of the accessions in the tea plant core collection exhibited a pattern nearly identical to that of the accessions in the entire collection, further supporting the broad representation of the core germplasm in Anhui Province.  The results demonstrated that the core collection could represent the genetic diversity of the original collection.  Our present work is valuable for the high-efficiency conservation and utilization of tea plant germplasms in Anhui Province

Plant Protection
Colonization by Klebsiella variicola FH-1 stimulates soybean growth and alleviates the stress of Sclerotinia sclerotiorum
ZHAI Qian-hang, PAN Ze-qun, ZHANG Cheng, YU Hui-lin, ZHANG Meng, GU Xue-hu, ZHANG Xiang-hui, PAN Hong-yu, ZHANG Hao
2023, 22(9): 2729-2745.  DOI: 10.1016/j.jia.2023.01.007
Abstract ( )   PDF in ScienceDirect  

Sclerotinia stem rot, caused by Sclerotinia sclerotiorum, is a destructive soil-borne disease leading to huge yield loss.  We previously reported that Klebsiella variicola FH-1 could degrade atrazine herbicides, and the vegetative growth of atrazine-sensitive crops (i.e., soybean) was significantly increased in the FH-1-treated soil.  Interestingly, we found that FH-1 could promote soybean growth and induce resistance to Ssclerotiorum.  In our study, strain FH-1 could grow in a nitrogen-free environment, dissolve inorganic phosphorus and potassium, and produce indoleacetic acid and a siderophore.  The results of pot experiments showed that Kvariicola FH-1 promoted soybean plant development, substantially improving plant height, fresh weight, and root length, and induced resistance against Ssclerotiorum infection in soybean leaves.  The area under the disease progression curve (AUDPC) for treatment with strain FH-1 was significantly lower than the control and was reduced by up to 42.2% within 48 h (P<0.001).  Moreover, strain FH-1 rcovered the activities of catalase, superoxide dismutase, peroxidase, phenylalanine ammonia lyase, and polyphenol oxidase, which are involved in plant protection, and reduced malondialdehyde accumulation in the leaves.  The mechanism of induction of resistance appeared to be primarily resulted from the enhancement of transcript levels of PR10, PR12, AOS, CHS, and PDF1.2 genes.  The colonization of FH-1 on soybean root, determined using CLSM and SEM, revealed that FH-1 colonized soybean root surfaces, root hairs, and exodermis to form biofilms.  In summary, Kvariicola FH-1 exhibited the biological control potential by inducing resistance in soybean against Ssclerotiorum infection, providing new suggestions for green prevention and control.

Degradation effects on dichlorvos by a biocontrol strain, Trichoderma atroviride T23
SUN Jia-nan, SI Gao-yue, LIU Hong-yi, LI Ya-qian, WANG Xin-hua, CHEN Jie
2023, 22(9): 2746-2758.  DOI: 10.1016/j.jia.2023.01.009
Abstract ( )   PDF in ScienceDirect  

Excessive use of organophosphate pesticides (OP), such as dichlorvos, in farming system poses a threat to human health through potential contamination of environment.  To date, biodegradation has been prospected most promising approach to eliminate environmental OP residues.  Trichoderma species as a biological control microorganism is often exposed to the chemical pesticides applied in environments, so it is necessary to understand the mechanism of degradation of dichlorvos by Trichoderma.  In this study, dichlorvos significantly inhibited the growth, sporulation and pigmentation of Tatroviride T23, and the dichlorvos degradation activity of T23 required the initial induction effect of dichlorvos and the culture conditions, including the nutrient and pH values of the medium.  Various changed primary and secondary metabolites released from T23 in the presence of dichlorvos were speculated as the energy and antioxidants for the strain itself to tolerate dichlorvos stress.  The results showed that T23 could produce a series of enzymes, especially the intracellular enzymes, to degrade dichlorvos.  The activities of the intracellular enzyme generated by T23 were differentially changed along time course and especially relied on initial dichlorvos concentration, ammonium sulfate and phosphate added in the medium.  In conclusion, some dichlorvos-induced chemical degradation related enzymes of T23 were proved to be involved in the degradation of dichlorvos.

Novel 18β-glycyrrhetinic acid amide derivatives show dual-acting capabilities for controlling plant bacterial diseases through ROS-mediated antibacterial efficiency and activating plant defense responses
SONG Ying-lian, LIU Hong-wu, YANG Yi-hong, HE Jing-jing, YANG Bin-xin, YANG Lin-li, ZHOU Xiang, LIU Li-wei, WANG Pei-yi, YANG Song
2023, 22(9): 2759-2771.  DOI: 10.1016/j.jia.2022.10.009
Abstract ( )   PDF in ScienceDirect  

Natural products have long been a crucial source of, or provided inspiration for new agrochemical discovery.  Naturally occurring 18β-glycyrrhetinic acid shows broad-spectrum bioactivities and is a potential skeleton for novel drug discovery.  To extend the utility of 18β-glycyrrhetinic acid for agricultural uses, a series of novel 18β-glycyrrhetinic acid amide derivatives were prepared and evaluated for their antibacterial potency.  Notably, compound 5k showed good antibacterial activity in vitro against Xanthomonas oryzae pv. oryzae (Xoo, EC50=3.64 mg L–1), and excellent protective activity (54.68%) against Xoo in vivo.  Compound 5k induced excessive production and accumulation of reactive oxygen species in the tested pathogens, resulting in damaging the bacterial cell envelope.  More interestingly, compound 5k could increase the activities of plant defense enzymes including catalase, superoxide dismutase, peroxidase, and phenylalanine ammonia lyase.  Taken together, these enjoyable results suggested that designed compounds derived from 18β-glycyrrhetinic acid showed potential for controlling intractable plant bacterial diseases by disturbing the balance of the phytopathogen’s redox system and activating the plant defense system

Light intensity regulates the sexual behaviors of oriental fruit fly Bactrocera dorsalis under laboratory conditions
REN Cong, ZHANG Jie, YUAN Jin-xi, WU Yun-qi-qi-ge, YAN Shan-chun, LIU Wei, WANG Gui-rong
2023, 22(9): 2772-2782.  DOI: 10.1016/j.jia.2023.04.025
Abstract ( )   PDF in ScienceDirect  

The oriental fruit fly, Bactrocera dorsalis (Hendel), is a devastating pest of citrus fruits.  After successful mating, adult females insert their eggs into the ripened fruit, resulting in moldy and rotten fruit and causing great economic losses for the citrus industry.  In the field, flies initiate copulatory behaviors as twilight approaches, and decreasing light intensity in this period is the normal stimulus for copulation.  In this study, ten light intensities ranging from 0–30 000 lux were set to identify the typical intensity that strongly regulates the copulation behavior of Bdorsalis.  Three light intensities found to regulate the copulation behavior were then selected to verify their effects on adult male wing fanning and female chemotaxis towards 2,3,5-trimethylpyrazine (TMP).  At last, strong light and complete darkness were artificially combined in the lab to verify whether they could prevent copulation to inform behavioral manipulation of oriental flies in the future.  The results indicated that adult flies generally initiated copulatory behaviors at low light intensity (<1 000 lux).  
Stronger light significantly prevented copulation in proportion to intensity, with nearly no copulation events initiated when light intensity was above 20 000 lux.  Both male wing fanning and female chemotaxis towards TMP were attenuated as light intensity became stronger.  However, at 10 000 lux, males still fanned their wings to a certain extent while TMP completely lost its attractiveness to females.  In the darkness, adults did not initiate any sexual behaviors, e.g., copulation, wing fanning, or chemotaxis to TMP.  One hour of strong light (10 000 lux) combined with continuous darkness completely prevented mating.  These results show that light condition is an essential factor for copulatory behaviors in the oriental fruit fly.  Researchers could thus manipulate light conditions artificially or disrupt the molecular target in flies’ light transduction pathway to develop environmentally-friendly techniques to control this pest.

Monitoring the little fire ant, Wasmannia auropunctata (Roger 1863), in the early stage of its invasion in China: Predicting its geographical distribution pattern under climate change 
ZHAO Hao-xiang, XIAN Xiao-qing, GUO Jian-yang, YANG Nian-wan, ZHANG Yan-ping, CHEN Bao-xiong, HUANG Hong-kun, LIU Wan-xue
2023, 22(9): 2783-2795.  DOI: 10.1016/j.jia.2022.12.004
Abstract ( )   PDF in ScienceDirect  

Invasive alien ants (IAAs) are among the most aggressive, competitive, and widespread invasive alien species (IAS) worldwide.  Wasmannia auropunctata, the greatest IAAs threat in the Pacific region and listed in “100 of the world’s worst IAS”, has established itself in many countries and on islands worldwide.  Wild populations of Wauropunctata were recently reported in southeastern China, representing a tremendous potential threat to China’s agricultural, economic, environmental, public health, and social well-being.  Estimating the potential geographical distribution (PGD) of Wauropunctata in China can illustrate areas that may potentially face invasion risk.  Therefore, based on the global distribution records of Wauropunctata and bioclimatic variables, we predicted the geographical distribution pattern of Wauropunctata in China under the effects of climate change using an ensemble model (EM).  Our findings showed that artificial neural network (ANN), flexible discriminant analysis (FDA), gradient boosting model (GBM), Random Forest (RF) were more accurate than categorical regression tree analysis (CTA), generalized linear model (GLM), maximum entropy model (MaxEnt) and surface distance envelope (SRE).  The mean TSS values of ANN, FDA, GBM, and RF were 0.820, 0.810, 0.843, and 0.857, respectively, and the mean AUC values were 0.946, 0.954, 0.968, and 0.979, respectively.  The mean TSS and AUC values of EM were 0.882 and 0.972, respectively, indicating that the prediction results with EM were more reliable than those with the single model.  The PGD of Wauropunctata in China is mainly located in southern China under current and future climate change.  Under climate change, the PGD of Wauropunctata in China will expand to higher-latitude areas.  The annual temperature range (bio7) and mean temperature of the warmest quarter (bio10) were the most significant variables affecting the PGD of Wauropunctata in China.  The PGD of Wauropunctata in China was mainly attributed to temperature variables, such as the annual temperature range (bio7) and the mean temperature of the warmest quarter (bio10).  The populations of Wauropunctata in southern China have broad potential invasion areas.  Developing strategies for the early warning, monitoring, prevention, and control of Wauropunctata in southern China requires more attention.

A binary gridding path-planning method for plant-protecting UAVs on irregular fields
XU Wang-ying, YU Xiao-bing, XUE Xin-yu
2023, 22(9): 2796-2809.  DOI: 10.1016/j.jia.2023.02.029
Abstract ( )   PDF in ScienceDirect  
The use of plant-protecting unmanned aerial vehicles (UAVs) for pesticide spraying is an essential operation in modern agriculture.  The balance between reducing pesticide consumption and energy consumption is a significant focus of current research in the path-planning of plant-protecting UAVs.  In this study, we proposed a binarization multi-objective model for the irregular field area, specifically an improved non-dominated sorting genetic algorithm–II based on the knee point and plane measurement (KPPM-NSGA-ii).  The binarization multi-objective model is applied to convex polygons, concave polygons and fields with complex terrain.  The experiments demonstrated that the proposed KPPM-NSGA-ii can obtain better results than the unplanned path method whether the optimization of pesticide consumption or energy consumption is preferred.  Hence, the proposed algorithm can save energy and pesticide usage and improve the efficiency in practical applications.
Animal Science · Veterinary Medicine
Immunogenetic basis of chicken’s heterophil to lymphocyte ratio revealed by genome-wide indel variants analysis
ZHANG Jin, WANG Jie, WANG Qiao, CUI Huan-xian, DING Ji-qiang, WANG Zi-xuan, Mamadou Thiam, LI Qing-he, ZHAO Gui-ping
2023, 22(9): 2810-2823.  DOI: 10.1016/j.jia.2022.12.012
Abstract ( )   PDF in ScienceDirect  

Enhancing host immunity is an effective way to reduce morbidity in chickens.  Heterophil to lymphocyte ratio (H/L) is associated with host disease resistance in birds.  Chickens with different H/L levels show different disease resistances.  However, the utility of the H/L as an indicator of immune function needs to be further analyzed.  In this study, a H/L directional breeding chicken line (Jingxing yellow chicken) was constructed, which has been bred for 12 generations.  We compared the function of heterophils, and combined statistical analysis to explore the candidate genes and pathways related to H/L.  The oxidative burst function of the heterophils isolated from the H/L selection line (G12) was increased (P=0.044) compared to the non-selection line (NS).  The 22.44 Mb genomic regions which annotated 300 protein-coding genes were selected in the genome of G9 (n=92) compared to NS (n=92) based on a genome-wide selective sweep.  Several selective regions were identified containing genes like interferon induced with helicase C domain 1 (IFIH1) and moesin (MSN) associated with the intracellular receptor signaling pathway, C–C motif chemokine receptor 6 (CCR6), dipeptidyl peptidase 4 (DPP4) and hemolytic complement (HC) associated with the negative regulation of leukocyte chemotaxis and tight junction protein 1 (TJP1) associated with actin cytoskeleton organization.  In addition, 45 genome-wide significant indels containing 29 protein-coding genes were also identified as associated with the H/L based on genome-wide association study (GWAS).  The expression of protein tyrosine phosphatase non-receptor type 5 (PTPN5) (r=0.75, P=0.033) and oxysterol binding protein like 5 (OSBPL5) (r=0.89, P=0.0027) were positively correlated with H/L.  Compared to the high H/L group, the expressions of PTPN5 and OSBPL5 were decreased (P<0.05) in the low H/L group of Beijing you chicken.  The A/A allelic frequency of indel 5_13108985 (P=3.85E–06) within OSBPL5 gradually increased from the NS to G5 and G9, and the individuals with A/A exhibited lower H/L than individuals with heterozygote A/ATCT (P=4.28E–04) and homozygous ATCT/ATCT (P=3.40E–05).  Above results indicated oxidative burst function of heterophils were enhanced, and 22.44 Mb genomic regions were selected with the directional selection of H/L.  In addition, PTPN5 and OSBPL5 genes were identified as H/L-related candidate genes.  These findings revealed the complex genetic mechanism of H/L related to immunity and will allow selection for improving chicken immunity based on the H/L

Preparation and application of a novel monoclonal antibody specific for the heat shock protein 60 of Lawsonia intracellularis
XIAO Ning, LÜ Yun-yun, LI Jian-nan, CHEN Chang-feng, LIN Hui-xing, FAN Hong-jie
2023, 22(9): 2824-2833.  DOI: 10.1016/j.jia.2023.04.006
Abstract ( )   PDF in ScienceDirect  

Porcine proliferative enteropathy (PPE), an important infectious disease in pig production caused by an obligate intracellular bacterium Lawsonia intracellularis, is commonly associated with diarrhea and reduced weight gain in growing pigs widespread.  An accurate method for detecting Lintracellularis is particularly important for preventing and controlling PPE.  Heat shock protein 60 (Hsp60) is an immunodominant bacterial antigen found in all eukaryotic and prokaryotic organisms.  Thus, the purpose of the current investigation was to produce a novel Lintracellularis Hsp60 monoclonal antibody (mAb) useful for immunodiagnostics.  Three hybridomas secreted anti-Hsp60 termed 3E5, 4E2, and 9G6 were generated, and the titers of ascitic fluids of 3E5, 4E2, 9G6 were 1:1 024 000, 1:2 048 000 and 1:2 048 000, respectively.  The Western blotting analysis demonstrated that recombinant Hsp60 (rHsp60) was recognized by mAbs 3E5, 4E2 and 9G6.  Subsequently, analyses of specificity showed all the mAbs were highly specific to Lintracellularis while could not significantly react with other enteric bacteria commonly found in the ileum of pigs, such as Escherichia coli, Salmonella Choleraesuis, Salmonella Typhimurium, and Brachyspira hyodysenteriae.  Furthermore, the mAbs were useful for detecting Lintracellularis in the infected monolayer cells and histological sections of the ileum from PPE-affected pigs.  Our research will provide a foundation for the development of immunological diagnostic tests

Identification and epitope mapping of anti-p72 single-chain antibody against African swine fever virus based on phage display antibody library
SONG Jin-xing, WANG Meng-xiang, ZHANG Yi-xuan, WAN Bo, DU Yong-kun, ZHUANG Guo-qing, LI Zi-bin, QIAO Song-lin, GENG Rui, WU Ya-nan, ZHANG Gai-ping
2023, 22(9): 2834-2847.  DOI: 10.1016/j.jia.2023.07.039
Abstract ( )   PDF in ScienceDirect  

African swine fever virus (ASFV) is a lethal pathogen that causes severe threats to the global swine industry and it has already had catastrophic socio-economic effects.  To date, no licensed prophylactic vaccine exists.  Limited knowledge exists about the major immunogens of ASFV and the epitope mapping of the key antigens.  As such, there is a considerable requirement to understand the functional monoclonal antibodies (mAbs) and the epitope mapping may be of utmost importance in our understanding of immune responses and designing improved vaccines, therapeutics, and diagnostics.  In this study, we generated an ASFV antibody phage-display library from ASFV convalescent swine PBMCs, further screened a specific ASFV major capsid protein (p72) single-chain antibody and fused with an IgG Fc fragment (scFv-83-Fc), which is a specific recognition antibody against ASFV Pig/HLJ/2018 strain.  Using the scFv-83-Fc mAb, we selected a conserved epitope peptide (221MTGYKH226) of p72 retrieved from a phage-displayed random peptide library.  Moreover, flow cytometry and cell uptake experiments demonstrated that the epitope peptide can significantly promote BMDCs maturation in vitro and could be effectively uptaken by DCs, which indicated its potential application in vaccine and diagnostic reagent development.  Overall, this study provided a valuable platform for identifying targets for ASFV vaccine development, as well as to facilitate the optimization design of subunit vaccine and diagnostic reagents

Agro-ecosystem & Environment
Carbon sequestration rate, nitrogen use efficiency and rice yield responses to long-term substitution of chemical fertilizer by organic manure in a rice–rice cropping system
Nafiu Garba HAYATU, LIU Yi-ren, HAN Tian-fu, Nano Alemu DABA, ZHANG Lu, SHEN Zhe, LI Ji-wen, Haliru MUAZU, Sobhi Faid LAMLOM, ZHANG Hui-min
2023, 22(9): 2848-2864.  DOI: 10.1016/j.jia.2022.12.006
Abstract ( )   PDF in ScienceDirect  

Combined application of chemical fertilizers with organic amendments was recommended as a strategy for improving yield, soil carbon storage, and nutrient use efficiency.  However, how the long-term substitution of chemical fertilizer with organic manure affects rice yield, carbon sequestration rate (CSR), and nitrogen use efficiency (NUE) while ensuring environmental safety remains unclear.  This study assessed the long-term effect of substituting chemical fertilizer with organic manure on rice yield, CSR, and NUE.  It also determined the optimum substitution ratio in the acidic soil of southern China.  The treatments were: (i) NPK0, unfertilized control; (ii) NPK1, 100% chemical nitrogen, phosphorus, and potassium fertilizer; (iii) NPKM1, 70% chemical NPK fertilizer and 30% organic manure; (iv) NPKM2, 50% chemical NPK fertilizer and 50% organic manure; and (v) NPKM3, 30% chemical NPK fertilizer and 70% organic manure.  Milk vetch and pig manure were sources of manure for early and late rice seasons, respectively.  The result showed that SOC content was higher in NPKM1, NPKM2, and NPKM3 treatments than in NPK0 and NPK1 treatments.  The carbon sequestration rate increased by 140, 160, and 280% under NPKM1, NPKM2, and NPKM3 treatments, respectively, compared to NPK1 treatment.  Grain yield was 86.1, 93.1, 93.6, and 96.5% higher under NPK1, NPKM1, NPKM2, and NPKM3 treatments, respectively, compared to NPK0 treatment.  The NUE in NPKM1, NPKM2, and NPKM3 treatments was higher as compared to NPK1 treatment for both rice seasons.  Redundancy analysis revealed close positive relationships of CSR with C input, total N, soil C:N ratio, catalase, and humic acids, whereas NUE was closely related to grain yield, grain N content, and phenol oxidase.  Furthermore, CSR and NUE negatively correlated with humin acid and soil C:P and N:P ratios.  The technique for order of preference by similarity to ideal solution (TOPSIS) showed that NPKM3 treatment was the optimum strategy for improving CSR and NUE.  Therefore, substituting 70% of chemical fertilizer with organic manure could be the best management option for increasing CSR and NUE in the paddy fields of southern China

Integrating a novel irrigation approximation method with a process-based remote sensing model to estimate multi-years' winter wheat yield over the North China Plain
ZHANG Sha, YANG Shan-shan, WANG Jing-wen, WU Xi-fang, Malak HENCHIRI, Tehseen JAVED, ZHANG Jia-hua, BAI Yun
2023, 22(9): 2865-2881.  DOI: 10.1016/j.jia.2023.02.036
Abstract ( )   PDF in ScienceDirect  

Accurate estimation of regional winter wheat yields is essential for understanding the food production status and ensuring national food security.  However, using the existing remote sensing-based crop yield models to accurately reproduce the inter-annual and spatial variations in winter wheat yields remains challenging due to the limited ability to acquire irrigation information in water-limited regions.  Thus, we proposed a new approach to approximating irrigations of winter wheat over the North China Plain (NCP), where irrigation occurs extensively during the winter wheat growing season.  This approach used irrigation pattern parameters (IPPs) to define the irrigation frequency and timing.  Then, they were incorporated into a newly-developed process-based and remote sensing-driven crop yield model for winter wheat (PRYM–Wheat), to improve the regional estimates of winter wheat over the NCP.  The IPPs were determined using statistical yield data of reference years (2010–2015) over the NCP.  Our findings showed that PRYM–Wheat with the optimal IPPs could improve the regional estimate of winter wheat yield, with an increase and decrease in the correlation coefficient (R) and root mean square error (RMSE) of 0.15 (about 37%) and 0.90 t ha–1 (about 41%), respectively.  The data in validation years (2001–2009 and 2016–2019) were used to validate PRYM–Wheat.  In addition, our findings also showed R (RMSE) of 0.80 (0.62 t ha–1) on a site level, 0.61 (0.91 t ha–1) for Hebei Province on a county level, 0.73 (0.97 t ha–1) for Henan Province on a county level, and 0.55 (0.75 t ha–1) for Shandong Province on a city level.  Overall, PRYM–Wheat can offer a stable and robust approach to estimating regional winter wheat yield across multiple years, providing a scientific basis for ensuring regional food security.

Predicting and delineating soil temperature regimes of China using pedotransfer function
BAO Wan-kui, LEI Qiu-liang, JIANG Zhuo-dong, SUN Fu-jun, ZHANG Tian-peng, HU Ning, WANG Qiu-bing
2023, 22(9): 2882-2892.  DOI: 10.1016/j.jia.2023.02.038
Abstract ( )   PDF in ScienceDirect  
Soil temperature regime (STR) is important for soil classification and land use.  Generally, STR is delineated by estimating the mean annual soil temperature at a depth of 50 cm (MAST50) according to the Chinese Soil Taxonomy (CST).  However, delineating the STR of China remains a challenge due to the difficulties in accurately estimating MAST50.  The objectives of this study were to explore environmental factors that influence the spatial variation of MAST50 and generate an STR map for China.  Soil temperature measurements at 40 and 80 cm depth were collected from 386 National Meteorological Stations in China during 1971–2000.  The MAST50 was calculated as the average mean annual soil temperature (MAST) from 1971–2000 between 40 and 80 cm depths.  In addition, 2 048 mean annual air temperature (MAAT) measurements from 1971 to 2000 were collected from the National Meteorological Stations across China.  A zonal pedotransfer function (PTF) was developed based on the ensemble linear regression kriging model to predict the MAST50 in three topographic steps of China.  The results showed that MAAT was the most important variable related to the variation of MAST50.  The zonal PTF was evaluated with a 10% validation dataset with a mean absolute error (MAE) of 0.66°C and root mean square error (RMSE) of 0.78°C, which were smaller than the unified model with MAE of 0.83°C and RMSE of 0.96°C, respectively.  This study demonstrated that the zonal PTF helped improve the accuracy of the predicted MAST50 map.  Based on the prediction results, an STR map across China was generated to provide a consistent scientific base for the improvement and application of CST and land use support.
Food Science
Effects of methionine treatment on storage quality and antioxidant activity of postharvest jujube fruit
LIU Yao, LEI Xing-meng, GUO Yu-xiao, YAO Shi-xiang, ZENG Kai-fang
2023, 22(9): 2893-2904.  DOI: 10.1016/j.jia.2023.06.004
Abstract ( )   PDF in ScienceDirect  
Jujube fruits usually suffer from physiological disorders or infectious diseases during storage, leading to quality deterioration, softening, or rotting.  Therefore, this study aims to investigate the effect of methionine soaking treatment on the postharvest jujube fruit decay rate and storage quality.  Methionine treatment significantly reduced the decay rate of postharvest jujube fruit and effectively maintained fruit color and titratable acid.  Methionine treatment effectively delayed the decrease of firmness, soluble solids, ascorbic acid, and lignin contents in jujube fruit.  Methionine treatment reduced the content of alanine and phenylalanine, and increased the content of glycine in jujube fruit, but displayed no significant effect on total amino acid content.  In addition, jujube fruits in the methionine treatment group had a higher total phenolic and flavonoid content and antioxidant capacity, both in free and bound forms.  Compared with the control, methionine treatment also significantly increased the content of individual phenolic acid fractions (gallic acid, vanillic acid, and syringic acid) and flavonoid fractions (catechin, epicatechin, rutin) in free form as well as individual phenolic acid fractions in bound form (gallic acid and ferulic acid) in jujube fruits.  Overall, this study suggested that the methionine treatment could be used as a prospective preservative to reduce the postharvest decay of jujube fruit and alleviate its nutritional quality deterioration during cold storage at 4°C.
Physicochemical properties and antibacterial mechanism of theabrownins prepared from different catechins catalyzed by polyphenol oxidase and peroxidase
CHEN Xiao-qiang, LIU Jia-yan, HUANG Xue-jun, WEI Yan-an, SHAO Rui-xiang, CHEN Ting-ting, XIE Jian-chun
2023, 22(9): 2905-2916.  DOI: 10.1016/j.jia.2023.07.004
Abstract ( )   PDF in ScienceDirect  

Theabrownins (TBs) are the characteristic functional and quality components of dark teas such as Pu’er tea and Chin-brick tea.  TBs are a class of water-soluble brown polymers with multi-molecular weight distribution produced by the oxidative polymerisation of tea polyphenols during the fermentation process of dark tea, both enzymatically and non-enzymatically.  TBs have been extracted and purified from dark tea all the time, but the obtained TBs contain heterogeneous components such as polysaccharides and caffeine in the bound state, which are difficult to remove.  The isolation and purification process was tedious and required the use of organic solvents, which made it difficult to industrialise TBs.  In this study, epigallocatechin (EGC), epigallocatechin gallate (EGCG), epigallocatechin gallate (ECG), EGC/EGCG (mass ratio 1:1), EGCG/ECG (mass ratio 1:1), EGC/ECG (mass ratio 1:1) and EGC/EGCG/ECG (mass ratio 1:1:1) as substrates and catalyzed by polyphenol oxidase (PPO) and peroxidase (POD) in turn to produce TBs, named TBs-dE-1, TBs-dE-2, TBs-dE-3, TBs-dE-4, TBs-dE-5, TBs-dE-6 and TBs-dE-7.  The physicochemical properties and the antibacterial activity and mechanism of TBs-dE-1–7 were investigated.  Sensory and colour difference measurements showed that all seven tea browning samples showed varying degrees of brownish hue.  Zeta potential in aqueous solutions at pH 3.0–9.0 indicated that TBs-dE-1–7 was negatively charged and the potential increased with increasing pH.  The characteristic absorption peaks of TBs-dE-1–7 were observed at 208 and 274 nm by UV-visible (UV-vis) scanning spectroscopy.  Fourier transform infrared (FT-IR) spectra indicated that they were phenolic compounds.  TBs-dE-1–7 showed significant inhibition of Escherichia coli DH5α (Ecoli DH5α).  TBs-dE-3 showed the strongest inhibitory effect with minimum inhibitory concentration (MIC) of 1.25 mg mL–1 and MBC of 10 mg mL–1, followed by TBs-dE-5 and TBs-dE-6.  These three TBs-dEs were selected to further investigate their inhibition mechanism.  The TBs-dE was found to damage the extracellular membrane of Ecoli DH5α, causing leakage of contents, and increase intracellular reactive oxygen content, resulting in abnormal cell metabolism due to oxidative stress.  The results of the study provide a theoretical basis for the industrial preparation and product development of TBs.

A allele makes alkaline tolerance real
ZHANG Wan-ke, CHEN Shou-yi, ZHANG Jin-song
2023, 22(9): 2917-2919.  DOI: 10.1016/j.jia.2023.08.012
Abstract ( )   PDF in ScienceDirect