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2023 Vol. 22 No. 4 Previous Issue   

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Review
Crop Science
Horticulture
Plant Protection
Animal Science · Veterinary Medicine
Agro-ecosystem & Environment
Agricultural Economics and Management
Short Communication


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Online automated identification of farmland pests is an important auxiliary means of pest control. In practical applications, the online insect identification system is often unable to locate and identify the target pest accurately due to factors such as small target size, high similarity between species and complex backgrounds. To facilitate the identification of insect larvae, a two-stage segmentation method, MRUNet, was proposed in this study. We conducted model training and comparative testing of MRUNet and previous methods on a semantic segmentation dataset of nine common farmland pest larvae. The experimental results show that the proposed two-stage image segmentation strategy is effective in dealing with small targets in complex backgrounds. This study provides a reliable reference for the automated identification of insect larvae. The cover photo shows the workflow of the proposed two-stage segmentation strategy and the structure of MRUNet, which is provided by Dr. Qiao Xi and Dr. Wang Fukuan from Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, China. See pages 1117–1130 for more details.


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Review

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Multi-omics-driven development of alternative crops for natural rubber production YANG Ning, YANG Dan-dan, YU Xu-chen, XU Cao 2023, 22(4): 959-971.  DOI: 10.1016/j.jia.2023.03.007 Abstract ( )   PDF in ScienceDirect   Natural rubber (NR) is an irreplaceable biopolymer of economic and strategic importance owing to its unique physical and chemical properties.  The Pará rubber tree (Hevea brasiliensis (Willd. ex A. Juss.) Müll. Arg.) is currently the exclusive commercial source of NR, and it is primarily grown in plantations restricted to the tropical and subtropical areas of Southeast Asia.  However, current Pará rubber production barely meets the sharply increasing global industrial demand for rubber.  Petroleum-based synthetic rubber (SR) has been used to supplement the shortage of NR but its industrial performance is not comparable to that of NR.  Thus, there is an urgent need to develop new productive rubber crops with broader environmental adaptability.  This review summarizes the current research progress on alternative rubber-producing plants, including horticultural plants (Taraxacum kok-saghyz Rodin and Lactuca L. species), woody plants (Parthenium argentatum A. Gray and Eucommia ulmoides Oliv.), and other plant species with potential for NR production.  With an emphasis on the molecular basis of NR biosynthesis revealed by a multi-omics approach, we highlight new integrative strategies and biotechnologies for exploring the mechanism of NR biosynthesis with a broader scope, which may accelerate the breeding and improvement of new rubber crops.

Crop Science

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OsPPR9 encodes a DYW-type PPR protein that affects editing efficiency of multiple RNA editing sites and is essential for chloroplast development CHEN Chang-zhao, WANG Ya-Liang, HE Meng-xing, LI Zhi-wen, SHEN Lan, LI Qing, RE De-yong, HU Jiang, ZHU Li, ZHANG Guang-heng, GAO Zhen-yu, ZENG Da-li, GUO Long-biao, QIAN Qian, ZHANG Qiang 2023, 22(4): 972-980.  DOI: 10.1016/j.jia.2022.08.026 Abstract ( )   PDF in ScienceDirect   Photosynthesis occurs mainly in chloroplasts, whose development is regulated by proteins encoded by nuclear genes.  Among them, pentapeptide repeat (PPR) proteins participate in organelle RNA editing.  Although there are more than 450 members of the PPR protein family in rice, only a few affect RNA editing in rice chloroplasts.  Gene editing technology has created new rice germplasm and mutants, which could be used for rice breeding and gene function study.  This study evaluated the functions of OsPPR9 in chloroplast RNA editing in rice.  The osppr9 mutants were obtained by CRISPR/Cas9, which showed yellowing leaves and a lethal phenotype, with suppressed expression of genes associated with chloroplast development and accumulation of photosynthetic-related proteins.  In addition, loss of OsPPR9 protein function reduces the editing efficiency of rps8-C182, rpoC2-C4106, rps14-C80, and ndhB-C611 RNA editing sites, which affects chloroplast growth and development in rice.  Our data showed that OsPPR9 is highly expressed in rice leaves and encodes a DYW-PPR protein localized in chloroplasts.  Besides, the OsPPR9 protein was shown to interact with OsMORF2 and OsMORF9.  Together, our findings provide insights into the role of the PPR protein in regulating chloroplast development in rice.

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The miR164-TaNAC14 module regulates root development and abiotic-stress tolerance in wheat seedlings CHI Qing, DU Lin-ying, MA Wen, NIU Ruo-yu, WU Bao-wei, GUO Li-jian, MA Meng, LIU Xiang-li, ZHAO Hui-xian 2023, 22(4): 981-998.  DOI: 10.1016/j.jia.2022.08.016 Abstract ( )   PDF in ScienceDirect   Previous studies have revealed the miR164 family and the miR164-targeted NAC transcription factor genes in rice (Oryza sativa) and Arabidopsis that play versatile roles in developmental processes and stress responses.  In wheat (Triticum aestivum L.), we found nine genetic loci of tae-miR164 (tae-MIR164 a to i) producing two mature sequences that down-regulate the expression of three newly identified target genes of TaNACs (TaNAC1, TaNAC11, and TaNAC14) by the cleavage of the respective mRNAs.  Overexpression of tae-miR164 or one of its target genes (TaNAC14) demonstrated that the miR164-TaNAC14 module greatly affects root growth and development and stress (drought and salinity) tolerance in wheat seedlings, and TaNAC14 promotes root growth and development in wheat seedlings and enhances drought tolerance, while tae-miR164 inhibits root development and reduces drought and salinity tolerance by down-regulating the expression of TaNAC14.  These findings identify the miR164-TaNAC14 module as well as other tae-miR164-regulated genes which can serve as new genetic resources for stress-resistance wheat breeding.

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Development and characterization of wheat–Aegilops kotschyi 1Uk(1A) substitution line with positive dough quality parameters JIANG Yun, WANG De-li, HAO Ming, ZHANG Jie, LIU Deng-cai 2023, 22(4): 999-1008.  DOI: 10.1016/j.jia.2022.08.020 Abstract ( )   PDF in ScienceDirect   Exploring novel high molecular weight glutenin subunits (HMW-GSs) from wild related species is a strategy to improve wheat processing quality.  The objective of the present investigation was to identify the chromosomes of the wheat-alien introgression line N124, derived from the hybridization between Triticum aestivum with Aegilops kotschyi, and characterize the effects on quality-related traits.  Fluorescence in situ hybridization karyotypes showed that N124 is a disomic 1Uk(1A) substitution line.  Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and reversed-phase high-performance liquid chromatography verified N124 expressed two HMW-GSs of the Ae. kotschyi parent.  PacBio RNA sequencing and phylogenetic analysis confirmed that the two HMW-GSs were Ukx and Uky.  Compared to the wheat parent, the substitution line had no obvious agronomic defects except fewer grains per spike but improved several major quality parameters.  It can be served as a donor or bridge material for wheat quality improvement.

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Grain yield and nitrogen use efficiency of an ultrashort-duration variety grown under different nitrogen and seeding rates in direct-seeded and double-season rice in Central China WANG Xin-yu, YANG Guo-dong, XU Le, XIANG Hong-shun, YANG Chen, WANG Fei, PENG Shao-bing 2023, 22(4): 1009-1020.  DOI: 10.1016/j.jia.2022.08.019 Abstract ( )   PDF in ScienceDirect   Nitrogen (N) and seeding rates are important factors affecting grain yield and N use efficiency (NUE) in direct-seeded rice.  However, these factors have not been adequately investigated on direct-seeded and double-season rice (DDR) in Central China.  The objective of this study was to evaluate the effects of various N and seeding rates on the grain yield and NUE of an ultrashort-duration variety grown under DDR.  Field experiments were conducted in 2018 in Wuxue County and 2019 in Qichun County, Hubei Province, China with four N rates and three seeding rates.  The results showed that the grain yield of the ultrashort-duration variety ranged from 6.32 to 8.23 t ha–1 with a total growth duration of 85 to 97 days across all treatments with N application.  Grain yield was increased significantly by N application in most cases, but seeding rate had an inconsistent effect on grain yield.  Furthermore, the response of grain yield to the N rates was much higher than the response to seeding rates.  The moderate N rates of 100–150 and 70–120 kg N ha–1 in the early and late seasons, respectively, could fully express the yield potential of the ultrashort-duration variety grown under DDR.  Remarkably higher N responses and agronomic NUE levels were achieved in the early-season rice compared with the late-season rice due to the difference in indigenous soil N supply capacity (INS) between the two seasons.  Seasonal differences in INS and N response should be considered when crop management practices are optimized for achieving high grain yield and NUE in ultrashort-duration variety grown under DDR.

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Plastic-film-side seeding, as an alternative to traditional film mulching, improves yield stability and income in maize production in semi-arid regions ZHANG Bing-chao, HU Han, GUO Zheng-yu, GONG Shuai, SHEN Si, LIAO Shu-hua, WANG Xin, ZHOU Shun-li, ZHANG Zhong-dong 2023, 22(4): 1021-1034.  DOI: 10.1016/j.jia.2022.08.017 Abstract ( )   PDF in ScienceDirect   Planting under plastic-film mulches is widely used in spring maize production in arid-cold regions for water conservation and warming the soil.  To ameliorate the associated issues such as plastic-film residues and additional labor during the “seedling release” in spring maize production, we have developed a plastic-film-side seeding (PSS) technology with the supporting machinery.  In the semi-arid regions of Northwest China, a 7-year trial demonstrated that PSS increased plant number per hectare by 6 547 and maize yield by 1 686 kg ha–1 compared with the traditional method of seeding under plastic-film mulch (PM).  Two-year experiments were conducted in two semi-arid regions to further understand the effects of PSS on three important aspects of production: (i) the moisture and temperature of soil, (ii) maize development, yield output, and water use efficiency (WUE), and (iii) the revenue and plastic-film residuals in comparison with that of flat planting (CK) and PM.  Continuous monitoring of the soil status demonstrated that, compared with CK, the PSS treatment significantly increased the temperature and moisture of the 0–20 cm soil in the seeding row at the early stage of maize development, and it also promoted grain yield (at 884–1 089 kg ha–1) and WUE, achieving a similar effect as the PM treatment.  Economically, the labor inputs of PSS were equal to CK, whereas the PM cost an additional 960 CNY ha–1 in labor for releasing the seedlings from below the film.  Overall, the PSS system increased profits by 5.83% (547 CNY ha–1 yr–1) and 8.16% (748 CNY ha–1 yr–1) compared with CK and PM, respectively.  Environmentally, PSS achieved a residual film recovery rate of nearly 100% and eliminated 96 to 130 kg ha–1 of residual plastic-film in PM in 3–5 years of maize production.  Collectively, these results show that PSS is an eco-friendly technique for improving yield stability and incomes for the sustainable production of maize in semi-arid regions.

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Root pruning is effective in alleviating the inhibition of soybean growth caused by anaerobic stress for a short period Koji YAMANE, Miki MARIYAMA, Yoshihiro HIROOKA, Morio IIJIMA 2023, 22(4): 1035-1044.  DOI: 10.1016/j.jia.2022.08.028 Abstract ( )   PDF in ScienceDirect   Soybean is an important upland crop, but its productivity is often limited by anaerobic stress caused by waterlogging.  The ability to adjust root growth under environmental constraints is an important physiological trait for adapting to an ever-changing environment, and root pruning is an artificial technique for regenerating the root system.  In the present study, we investigated whether root pruning in soybean can effectively alleviate the inhibitory effects of anaerobic stress.  Soybean plants were affected by anaerobic stress at the germination, vegetative stage 1 (V1), and reproductive stage 1 (R1) stages, and then the plants were treated with root pruning just after the stress treatment.  Soybean plants at the germination stage were treated with root cap and tip removals after hypoxia (N2 treatment).  Root cap removal was more effective in suppressing the inhibitory effects of hypoxia than root tip removal (5 mm from the tip).  The shoot dry weights of the soybean plants with and without root cap removal after hypoxia were 51.2 and 73.8% of the control, respectively, while the root dry weights of plants with and without root cap removal after hypoxia were 43.2 and 62.8% of the control, respectively.  As root cap removal effectively enhanced soybean growth after anaerobic stress, the root cap may be the candidate tissue for the stress memory mechanism.  When soybean plants at the V1 stage of growth were affected by anaerobic stress, the branch number, pod weight in the main stem, root length, and root surface area of the soybean plants treated with anaerobic stress at the R1 stage significantly decreased compared with those of the control.  In contrast, root pruning (2 mm from the tip) immediately after the stress treatment enhanced root growth, branch number, and pod weight.  The branch number, pod weight, root length, and root surface area of the plants treated with root pruning were 1.13, 1.14, 1.12, and 1.13 times higher than those of plants treated with anaerobic stress.  Plasmolysis was observed in the root meristem, columella, and cortical cells in soybean roots subjected to anaerobic conditions.  However, damage was not observed in the newly emerged roots after root pruning in plants treated with anaerobic stress.  These results suggested that root pruning is effective in enhancing soybean growth after anaerobic stress.  This effectiveness may be due to the regeneration and elongation of healthy lateral roots during the recovery period.  When soybean plants were affected by anaerobic stress at the R1 stage, root pruning just after the stress treatment was ineffective.  Thus, suppressing the growth reduction due to anaerobic stress at reproductive stages using only root pruning may be difficult.

Horticulture

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Optimization of slow-release fertilizer application improves lotus rhizome quality by affecting the physicochemical properties of starch ZHAO Shu-ping, DENG Kang-ming, ZHU Ya-mei, JIANG Tao, WU Peng, FENG Kai, LI Liang-jun 2023, 22(4): 1045-1057.  DOI: 10.1016/j.jia.2023.01.005 Abstract ( )   PDF in ScienceDirect   To achieve the dual goals of high yield and good quality with low environmental costs, slow-release fertilizer (SRF) has been widely used in lotus cultivation as new type of fertilizer instead of traditional nitrogen fertilizer.  However, the optimal amount of SRF and how it would promote lotus rhizome quality remain unclear.  This study was designed to investigate the photosynthetic characteristics and the synthesis, accumulation, and physicochemical properties of lotus rhizome starches under six SRF levels (CK, S1, S2, S3, S4, and S5).  Compared with CK (0 kg ha–1), the net photosynthetic rate (Pn) and SPAD values of leaves remained at higher levels under SRF treatment.  Further research showed that SRF increased the lotus rhizome yield, the contents of amylose, amylopectin, and total starch, and the number of starch granules.  Among the six SRF levels, S3 (1 035 kg ha–1) showed the greatest difference from CK and produced the highest levels.  With the increasing SRF levels, the peak, hot and final viscosities decreased at first and then increased, but the setback viscosity and pasting temperature increased.  In order to interpret these changes at the molecular level, the activities of key enzymes and relative expression levels of starch accumulation related genes were analyzed.  Each of these parameters also increased under SRF treatment, especially under the S3 treatment.  The results of this study show that SRF, especially S3 (1 035 kg ha–1), is a suitable fertilizer option for lotus planting which can improve lotus rhizome quality by affecting starch accumulations related enzymes and genes.  These results will be useful for SRF application to high-quality lotus rhizome production with low environmental costs.

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Isolation and functional analysis of SrMYB1, a direct transcriptional repressor of SrUGT76G1 in Stevia rebaudiana ZHANG Ting, ZHANG Yong-xia, SUN Yu-ming, XU Xiao-yang, WANG Yin-jie, CHONG Xin-ran, YANG Yong-heng and YUAN Hai-yan 2023, 22(4): 1058-1067.  DOI: 10.1016/j.jia.2023.03.001 Abstract ( )   PDF in ScienceDirect   SrUGT76G1, the most well-studied diterpene glycosyltransferase in Stevia rebaudiana, is key to the biosynthesis of economically important steviol glycosides (SGs).  However, the molecular regulatory mechanism of SrUGT76G1 has rarely been explored.  In this study, we identified a MYB transcription factor, SrMYB1, using a yeast one-hybrid screening assay.  SrMYB1 belongs to the typical R2R3-type MYB protein and is specifically localized in the nucleus with strong transactivation activity.  The transcript of SrMYB1 is predominantly accumulated in flowers, but is also present at a lower level in leaves.  Yeast one-hybrid and electrophoretic mobility shift assays verified that SrMYB1 binds directly to the MYB binding sites in the F4-3 fragment (+50–(–141)) of the SrUGT76G1 promoter.  Furthermore, we found that SrMYB1 could significantly repress the expression of SrUGT76G1 in both epidermal cells of tobacco leaves and stevia callus.  Taken together, our results demonstrate that SrMYB1 is an essential upstream regulator of SrUGT76G1 and provide novel insight into the regulatory network for the SGs metabolic pathway in S. rebaudiana.

Plant Protection

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Transcriptional regulation of secondary metabolism and autophagy genes in response to DNA replication stress in Setosphaeria turcica MENG Ya-nan, ZHANG Xin-jie, ZENG Fan-li, ZHAI Wei-bo, LI Pan, HU Jing-jing, XIAO Sheng-lin, HAO Zhi-min, CAO Zhi-yan, CHEN Chuan, DONG Jin-gao 2023, 22(4): 1068-1081.  DOI: 10.1016/j.jia.2022.07.002 Abstract ( )   PDF in ScienceDirect   The fungal pathogen Setosphaeria turcica causes northern corn leaf blight (NCLB), which leads to considerable crop losses.  Setosphaeria turcica elaborates a specialized infection structures called appressorium for maize infection.  Previously, we demonstrated that the S. turcica triggers an S-phase checkpoint and ATR (Ataxia Telangiectasia and Rad3 related)-dependent self-protective response to DNA genotoxic insults during maize infection.  However, how the regulatory mechanism works was still largely unknown.  Here, we report a genome wide transcriptional profile analysis during appressorium formation in the present of DNA replication stress.  We performed RNA-Seq analysis to identify S. tuicica genes responsive to DNA replication stress.  In the current work, we found that appressorium-mediated maize infection by S. turcica is significantly blocked by S-phase checkpoint.  A large serial of secondary metabolite and melanin biosynthesis genes were blocked in appressorium formation of S. turcica during the replication stress.  The secondary metabolite biosynthesis genes including alcohol dehydrogenase GroES-like domain, multicopper oxidase, ABC-transporter families, cytochrome P450 and FAD-containing monooxygenase were related to plant pathogen infection.  In addition, we demonstrated that autophagy in S. turcica is up-regulated by ATR as a defense response to stress.  We identified StATG3, StATG4, StATG5, StATG7 and StATG16 genes for autophagy were induced by ATR-mediated S-phase checkpoint.  We therefore propose that in response to genotoxic stress, S. turcica utilizes ATR-dependent pathway to turn off transcription of genes governing appressorium-mediated infection, and meanwhile inducing transcription of autophagy genes likely as a mechanism of self-protection, aside from the more conservative responses in eukaryotes.

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Characterization of the microbial community response to replant diseases in peach orchards LI Wei-hua, CHEN Peng, WANG Yu-zhu, LIU Qi-zhi 2023, 22(4): 1082-1092.  DOI: 10.1016/j.jia.2022.08.121 Abstract ( )   PDF in ScienceDirect   This study attempted to monitor the development of microbial communities and reveal the correlation between the soil microbial community and soil nutrient factors over different years following the replanting of peach trees.  The replanted soil (RS) and nonreplanted soil (NRS) were collected from peach orchards with different growth years (1, 3, 5, 7, 9, 11, and 13 years) in the same region.  The soil bacterial and fungal community diversities were analyzed by high-throughput sequencing technology.  Redundancy analysis (RDA) was used to show the correlation between the soil microbial community and environmental variables.  The alpha diversities of the bacterial and fungal communities indicated that RS contained a higher abundance of bacterial and fungal operational taxonomic units (OTUs) than NRS.  NMDS and ANOSIM analyses showed that the soil bacterial and fungal communities were significantly (P<0.01) affected by planting years, and that the main changes occurred in the first and ninth planting years.  The presence of the bacterial orders Sphingobacteriales, Burkholderiales and Actinomycetales changed significantly after replanting.  Some bacteria associated with bioremediation, such as Burkholderiales and Intrasporangiaceae, and some harmful pathogens, such as Penicillium and Ophiostomatales, significantly increased after replanting (LDA score>3.0).  In addition, the soil nutrient contents were lower in RS than in NRS in the early stage (1–5 years), and the RDA showed that bacterial and fungal phyla are closely associated with environmental variables, including the potential of hydrogen (pH), ammonium nitrogen (AN), available phosphorus (AP) and available potassium (AK).  These results lead to a deeper understanding of the microbial responses to replanting in peach orchards.

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Analysis of sex pheromone production and field trapping of the Asian corn borer (Ostrinia furnacalis Guenée) in Xinjiang, China DENG Jian-yu, LAN Chen-yi-hang, ZHOU Jun-xiang, YAO Yu-bo, YIN Xiao-hui, FU Kai-yun, DING Xin-hua, GUO Wen-chao, LIU Wen, WANG Na, Fumin WANG 2023, 22(4): 1093-1103.  DOI: 10.1016/j.jia.2022.08.042 Abstract ( )   PDF in ScienceDirect   Identifying the sex pheromone systems of local pest populations facilitates their management, especially for moth species that show significant geographic variation in sex pheromone communication.  We investigated the pheromone production and behavioral responses of the Asian corn borer (Ostrinia furnacalis Guenée; ACB) in Xinjiang, China.  The ACB produces three compounds: (Z)-12-tetradecenyl acetate (Z12-14:Ac) and (E)-12-tetradecenyl acetate (E12-14:Ac) which are two sex pheromone compounds, and n-tetradecyl acetate (14:Ac) which has variable roles in mediating behavioral responses.  The ratios of these three compounds produced in female gland are geographically distinct among different populations.  Quantitative analysis of pheromone production showed that the proportions of Z12-14:Ac in the E/Z isomers (i.e., Z and E12-14:Ac) and the proportions of 14:Ac in the ternary blend respectively averaged 60.46% (SD=5.26) and 25.00% (SD=7.37), with their probabilities normally or near-normally distributed.  Trapping experiments in a cornfield indicated that deploying the E/Z isomers and the three compounds in rubber septa close to their gland ratios yielded the most captured males, while other ratios that deviated from the gland ratios showed reduced field captures.  The ternary blend was significantly more attractive to males than the E/Z isomers in the field, indicating a functional role of 14:Ac as the third pheromone component used by the local population.  Additionally, the dose-response test demonstrated that the application of the three compounds at dosages between 200 and 350 μg attracted significantly more males compared to other dosages.  Therefore, the characterization of this local ACB pheromone system provides additional information about its geographic variation and serves as a basis for optimizing the pheromone-mediated control of this pest in Xinjiang.

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Azole selenourea disrupted the midgut and caused malformed development of Plutella xylostella  GUO Xue-ying, HUANG Zi-hao, XIONG Lan-tu, DONG Li, HUANG Yue-kun, WEI Lin-hao, TANG Ri-yuan, WANG Zhi-lin, XU Han-hong 2023, 22(4): 1104-1116.  DOI: 10.1016/j.jia.2022.09.001 Abstract ( )   PDF in ScienceDirect   Chemical insecticides targeting the digestive system of diamondback moth (DBM), Plutella xylostella, have not been developed.  The discovery of an insecticide with novel mode of action is a challenge for the control of DBM.  In this study, a class of selenium- and difluoromethyl-modified azoles (fluoroazole selenoureas, FASU) were designed and synthesized for the control of DBM.  Of these azoles, compound B4 showed the highest insecticidal activity against DBM.  The LC50 of third- and second-instar larvae reached 32.3 and 4.6 μg mL–1, respectively.  The midgut tissue of larvae was severely disrupted, and the larval intestinal tissue was dotted with unique red spots after treatment with compound B4.  Compound B4 led to disintegration of the peritrophic matrix, swelling of the midgut epithelium, fracture of the microvilli, and extensive leakage of cellular debris in the midgut lumen.  Surviving larvae grew very slowly, and the larval duration was significantly prolonged after exposure to compound B4 at sublethal doses (LC10, LC25 and LC50).  Furthermore, the pupation rate, emergence rate and pupae weight were significantly decreased.  Compound B4 also induced abnormal pupae, causing adults to be trapped in the cocoon or failure to fly due to twisted wings.  These results demonstrated that FASU could reduce the population of DBM in sublethal doses.  FASU is the first synthetic insecticidal lead compound that has been shown to disrupt the midgut tissue of the larvae of DBM, and its mode of action totally differs from that of commercial chemical insecticides.

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MRUNet: A two-stage segmentation model for small insect targets in complex environments  WANG Fu-kuan, HUANG Yi-qi, HUANG Zhao-cheng, SHEN Hao, HUANG Cong, QIAO Xi, QIAN Wan-qiang 2023, 22(4): 1117-1130.  DOI: 10.1016/j.jia.2022.09.004 Abstract ( )   PDF in ScienceDirect   Online automated identification of farmland pests is an important auxiliary means of pest control.  In practical applications, the online insect identification system is often unable to locate and identify the target pest accurately due to factors such as small target size, high similarity between species and complex backgrounds.  To facilitate the identification of insect larvae, a two-stage segmentation method, MRUNet was proposed in this study.  Structurally, MRUNet borrows  the practice of object detection before semantic segmentation from Mask R-CNN and then uses an improved lightweight UNet to perform the semantic segmentation.  To reliably evaluate the segmentation results of the models, statistical methods were introduced to measure the stability of the performance of the models among samples in addition to the evaluation indicators commonly used for semantic segmentation.  The experimental results showed that this two-stage image segmentation strategy is effective in dealing with small targets in complex backgrounds.  Compared with existing state-of-the-art semantic segmentation methods, MRUNet shows better stability and detail processing ability under the same conditions.  This study provides a reliable reference for the automated identification of insect larvae.

Animal Science · Veterinary Medicine

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MicroRNA-370-5p inhibits pigmentation and cell proliferation by downregulating mitogen-activated protein kinase kinase kinase 8 expression in sheep melanocytes JI Kai-yuan, WEN Ru-jun, WANG Zheng-zhou, TIAN Qian-qian, ZHANG Wei, ZHANG Yun-hai 2023, 22(4): 1131-1141.  DOI: 10.1016/j.jia.2023.02.018 Abstract ( )   PDF in ScienceDirect   In mammals, microRNAs (miRNAs) play key roles in multiple biological processes by regulating the expression of target genes.  Studies have found that the levels of miR-370-5p expression differ significantly in the skins of sheep with different hair colors; however, its function remains unclear.  In this study, we investigated the roles of miR-370-5p in sheep melanocytes and found that the overexpression of miR-370-5p significantly inhibited cell proliferation (P<0.01), tyrosinase activity (P=0.001) and significantly reduced (P<0.001) melanin production.  Functional prediction revealed that the 3´-untranslated region (UTR) of MAP3K8 has a putative miR-370-5p binding site, and the interaction between these two molecules was confirmed using luciferase reporter assays.  In situ hybridization assays revealed that MAP3K8 is expressed in the cytoplasm of melanocytes.  The results of quantitative RT-PCR and Western blotting analyses revealed that overexpression of miR-370-5p in melanocytes significantly inhibits (P<0.01) MAP3K8 expression via direct targeting of its 3´ UTR.  Inhibition of MAP3K8 expression by siRNA-MAP3K8 transfection induced a significant inhibition (P<0.01) of melanocyte proliferation and significant reduction (P<0.001) in melanin production, which is consistent with our observations for miR-370-5p.  Target gene rescue experiments indicated that the expression of MAP3K8 in melanocytes co-transfected with miR-370-5p and MAP3K8-cDNA (containing sites for the targeted binding to miR-370-5p) was significantly rescued (P≤0.001), which subsequently promoted significant increases in cell proliferation (P<0.001) and melanin production (P<0.01).  Collectively, these findings indicate that miR-370-5p plays a functional role in inhibiting sheep melanocyte proliferation and melanogenesis by downregulating the expression of MAP3K8.

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Effects of LPA on the development of sheep in vitro fertilized embryos and attempt to establish sheep embryonic stem cells ZHANG Xue-min, HUANG Xiang-hua, WANG Jing, XING Ying, LIU Fang, XIANG Jin-zhu, WANG Han-ning, YUE Yong-li, LI Xue-ling 2023, 22(4): 1142-1158.  DOI: 10.1016/j.jia.2022.08.111 Abstract ( )   PDF in ScienceDirect   Lysophosphatidic acid (LPA) is a small molecule glycerophospholipid, which regulates multiple downstream signalling pathways through G-protein-coupled receptors to achieve numerous functions on oocyte maturation and embryo development.  In this study, sheep in vitro fertilized embryos were applied to investigate the effects of LPA on early embryos development and embryonic stem cell establishment.  At first, the maturation medium containing estrus female sheep serum and synthetic oviduct fluid (SOF) were optimized for sheep IVF, and then the effects of LPA were investigated.  From 0.1 to 10 μmol L–1, LPA had no significant effect on the cleavage rate (P>0.05), but the maturation rate and blastocyst rate increased dependently with LPA concentration (P<0.05), and the blastocyst morphology was normal.  When the LPA concentration was 15 μmol L–1, the maturation rate, cleavage rate and blastocyst rate decreased significantly (P<0.05), and the blastocyst exhibited abnormal morphology and could not develop into high-quality blastocyst.  Besides, the exogenous LPA increases the expression of LPAR2, LPAR4, TE-related gene CDX-2 and pluripotency-related gene OCT-4 in sheep early IVF embryos with the raise of LPA concentration from 0.1 to 10 μmol L–1.  The expression of LPAR2, LPAR4, CDX-2 and OCT-4 from the LPA-0.1 μmol L–1 to LPA-10 μmol L–1 groups in early embryos were extremely significant (P<0.05), while the expression of these genes significantly decreased in 15 μmol L–1 LPA-treated embryos compared with LPA-10 μmol L–1 group (P<0.05).  The inner cell mass in 15 μmol L–1 LPA-treated embryos was also disturbed, and the blastocysts formation was abnormal.  Secondly, the sheep IVF blastocysts were applied to establish embryonic stem cells.  The results showed that LPA made the blastocyst inoculated cells grow towards TSC-like cells.  They enhanced the fluorescence intensity and mRNA abundance of OCT-4 and CDX-2 as the concentration increased from 0 to 10 μmol L–1, while 15 μmol L–1 LPA decreased OCT-4 and CDX-2 expression in the derived cells.  The expression of CDX-2 and OCT-4 in the blastocyst inoculated cells of LPA-1 μmol L–1 group and LPA-10 μmol L–1 group extremely significantly increased (P<0.05), but there was significant decrease in LPA-15 μmol L–1 group compared with LPA-10 μmol L–1 group (P<0.05).  Meanwhile, the protein expression of LPAR2 and LPAR4 remarkably increased after treatment of LPA at 10 μmol L–1 concentration.  This study references the IVF embryo production and embryonic stem cell research of domestic animals.

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Use of transcriptome sequencing to explore the effect of CSRP3 on chicken myoblasts SHAN Yan-ju, JI Gai-ge, ZHANG Ming, LIU Yi-fan, TU Yun-jie, JU Xiao-jun, SHU Jing-ting, ZOU Jian-min 2023, 22(4): 1159-1171.  DOI: 10.1016/j.jia.2022.08.067 Abstract ( )   PDF in ScienceDirect   The mechanisms that regulate the specificity and maintenance of chicken muscle fiber types remain largely unknown.  In mammals, CSRP3 has been shown to play a vital role in the maintenance of typical muscle structure and function.  This study investigated the role that CSRP3 plays in chicken skeletal muscle.  First, the antibody against chicken CSRP3 protein was prepared, and the expression levels of the mRNA and protein of the CSRP3 gene in four chicken skeletal muscles with different myofiber compositions were compared.  Then the effects of CSRP3 silencing on the expression profile of chicken myoblast transcriptomes were analyzed.  The results showed that the expression levels of the mRNA and protein of the CSRP3 gene were both associated with the composition of fiber types in chicken skeletal muscles.  A total of 650 genes with at least 1.5-fold differences (Q<0.05) were identified, of which 255 genes were upregulated and 395 genes were downregulated by CSRP3 silencing.  Functional enrichment showed that several pathways, including adrenergic signaling in cardiomyocytes, adipocytokine signaling pathway and apelin signaling pathway, were significantly (P<0.05) enriched both in differentially expressed genes and all expressed genes.  The co-expressed gene network suggested that CSRP3 silencing caused a compensatory upregulation (Q<0.05) of genes related to the assembly of myofibrils, muscle differentiation, and contraction.  Meanwhile, two fast myosin heavy chain genes (MyH1B and MyH1E) were upregulated (Q<0.05) upon CSRP3 silencing.  These results suggested that CSRP3 plays a crucial role in chicken myofiber composition, and affects the distribution of chicken myofiber types, probably by regulating the expression of MyH1B and MyH1E.

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Ensiling vine tea (Ampelopsis grossedentata) residue with Lactobacillus plantarum inoculant as an animal unconventional fodder WANG Yuan, ZHOU Hong-zhang, GAO Yu, WANG Ning-wei, LIU Han, YANG Fu-yu, NI Kui-kui 2023, 22(4): 1172-1183.  DOI: 10.1016/j.jia.2022.10.001 Abstract ( )   PDF in ScienceDirect   The study aimed to evaluate the application of silage fermentation in storing vine tea residue.  Dynamic of fermentation-related product, chemical component and bacterial community of silage with or without Lactobacillus plantarum F1 inoculant were analyzed.  The results showed that F1 treatment had a significant (P<0.05) impact on the lactic acid and ammoniacal nitrogen concentrations and pH value.  Total phenols were well preserved in both treatments.  After 30 days of ensiling, L. plantarum occupied the majority of Lactobacillus genus (more than 95%) in all silage samples.  Spearman revealed a positive (P<0.01) correlation between lactic acid content and Lactobacillus.  Overall, ensiling vine tea residue with L. plantarum can effectively preserve the nutritional attributes and total phenols, which offers a new insight into utilizing vine tea residue.

Agro-ecosystem & Environment

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Hole fertilization in the root zone facilitates maize yield and nitrogen utilization by mitigating potential N loss and improving mineral N accumulation SHI Wen-xuan, ZHANG Qian, LI Lan-tao, TAN Jin-fang, XIE Ruo-han, WANG Yi-lun 2023, 22(4): 1184-1198.  DOI: 10.1016/j.jia.2022.09.018 Abstract ( )   PDF in ScienceDirect   Reducing environmental impacts and improving N utilization are critical to ensuring food security in China.  Although root-zone fertilization has been considered an effective strategy to improve nitrogen use efficiency (NUE), the effect of controlled-release urea (CRU) applied in conjunction with normal urea in this mode is unclear.  Therefore, a 3-year field experiment was conducted using a no-N-added as a control and two fertilization modes (FF, furrow fertilization by manual trenching, i.e., farmer fertilizer practice; HF: root-zone hole fertilization by point broadcast manually) at 210 kg N ha–1 (controlled-release:normal fertilizer=5:5), along with a 1-year in-situ microplot experiment.  Maize yield, NUE and N loss were investigated under different fertilization modes.  The results showed that compared with FF, HF improved the average yield and N recovery efficiency by 8.5 and 22.3% over three years, respectively.  HF had a greater potential for application than FF treatment, which led to increases in dry matter accumulation, total N uptake, SPAD value and LAI.  In addition, HF remarkably enhanced the accumulation of 15N derived from fertilizer by 17.2% compared with FF, which in turn reduced the potential loss of 15N by 43.8%.  HF increased the accumulation of N in the tillage layer of soils at harvest for potential use in the subsequent season relative to FF.  Hence, HF could match the N requirement of summer maize, sustain yield, improve NUE and reduce environmental N loss simultaneously.  Overall, root-zone hole fertilization with blended CRU and normal urea can represent an effective and promising practice to achieve environmental integrity and food security on the North China Plain, which deserves further application and investigation.

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Green manuring facilitates bacterial community dispersal across different compartments of subsequent tobacco LIANG Hai, FU Li-bo, CHEN Hua, ZHOU Guo-peng, GAO Song-juan, CAO Wei-dong 2023, 22(4): 1199-1215.  DOI: 10.1016/j.jia.2022.08.043 Abstract ( )   PDF in ScienceDirect   Green manure–crop rotation is a sustainable approach to protect crops against diseases and improve yield.  However, the mechanism by which green manuring manipulates the crop-associated microbial community remains to be elucidated.  In this study, we explored the horizontal processes of bacterial communities in different compartments of the soil–root interface (bulk soil, rhizosphere soil, rhizoplane and endosphere) of tobacco by performing a field experiment including four rotation practices, namely, tobacco rotated with smooth vetch, ryegrass, radish, and winter fallow (without green manure).  Results showed that the co-occurrence networks constructed by adjacent compartments of the soil–root interface with green manuring had more edges than without green manuring, indicating  dramatic microbial interactions.  Green manuring increased the dispersal-niche continuum index between bulk soil and other compartments, indicating that it facilitated the horizontal dispersal of microbes.  For the different green manuring practices, the neutral community model explained 24.6–27.6% of detection frequency for bacteria, and at least one compartment under each practice had a normalized stochasticity ratio higher than the 50% boundary point, suggesting that the deterministic and stochastic processes jointly shaped the tobacco microbiome.  In conclusion, green manuring generally facilitates bacterial community dispersal across different compartments and enhances potential interactions among adjacent compartments.  This study provides empirical evidence for understanding the microbiome assembly under green manure–crop rotation.

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Combining the critical nitrogen concentration and machine learning algorithms to estimate nitrogen deficiency in rice from UAV hyperspectral data YU Feng-hua, BAI Ju-chi, JIN Zhong-yu, GUO Zhong-hui, YANG Jia-xin, CHEN Chun-ling 2023, 22(4): 1216-1229.  DOI: 10.1016/j.jia.2022.12.007 Abstract ( )   PDF in ScienceDirect   Rapid and large area acquisition of nitrogen (N) deficiency status is important for achieving the optimal fertilization of rice.  Most existing studies, however, focus on the use of unmanned aerial vehicle (UAV) remote sensing to diagnose N nutrition in rice, while there are fewer studies on the quantitative description of the degree of N deficiency in rice, and the effects of the critical N concentration on the spectral changes in rice have rarely been explored.  Therefore, based on the canopy spectral data obtained by remotely-sensed UAV hyperspectral images, the N content in rice was obtained through field sampling.  The construction method of the rice curve for the northeastern critical N concentration was studied, and on this basis, N deficiency was determined.  Taking the spectrum of the critical N concentration state as the standard spectrum, the spectral reflectivity data were transformed by the ratios and differences, and the feature extraction of the spectral data was carried out by the successive projections algorithm (SPA).  Finally, by taking the characteristic band as the input variable and N deficiency as the output variable, a set of multivariate linear regression (MLR), long short-term memory (LSTM) inversion models based on extreme learning machine (ELM), and the non-dominated sorting genetic algorithm III extreme learning machine (NSGA-III-ELM) were constructed.  The results showed two key aspects of this system: 1) The correlation between the N deficiency data and original spectrum was poor, but the correlation between the N deficiency data and N deficiency could be improved by a difference change and ratio transformation; 2) The inversion results based on the ratio spectrum and NSGA-III-ELM algorithm were the best, as the R2 values of the training set and validation set were 0.852 and 0.810, and the root mean square error (RMSE) values were 0.291 and 0.308, respectively.  From the perspective of the spectral data, the inversion accuracy of the ratio spectrum was better than the accuracy of the original spectrum or difference spectrum.  At the algorithm level, the model inversion results based on LSTM algorithms showed a serious overfitting phenomenon and poor inversion effect.  The inversion accuracy based on the NSGA-III-ELM algorithm was better than the accuracy of the MLR algorithm or the ELM algorithm.  Therefore, the inversion model based on the ratio spectrum and NSGA-III-ELM algorithm could effectively invert the N deficiency in rice and provide critical technical support for accurate topdressing based on the N status in the rice.

Agricultural Economics and Management

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Can food security and low carbon be achieved simultaneously? —An empirical analysis of the mechanisms influencing the carbon footprint of potato and corn cultivation in irrigation areas NIU Kunyu, GUO Hui, LIU Jing 2023, 22(4): 1230-1243.  DOI: 10.1016/j.jia.2023.02.010 Abstract ( )   PDF in ScienceDirect   Irrigated agriculture has tripled since 1950, accounting for 20% of the global arable land and 40% of food production.  Irrigated agriculture increases food security yet has controversial implications for global climate change.  Most previous studies have calculated carbon emissions and their composition in irrigated areas using the engineering approach to life-cycle assessment.  By combining life cycle assessment (LCA)-based carbon emissions accounting with econometric models such as multiple linear regression and structural equation modeling (SEM), we conducted an interdisciplinary study to identify the influencing factors and internal mechanisms of the carbon footprint (CFP) of smallholder crop cultivation on irrigation reform pilot areas.  To this end, we investigated corn and potato production data in the 2019–2020 crop years for 852 plots of 345 rural households in six villages (two irrigation agriculture pilot villages and four surrounding villages as controls) in Southwest China.  The crop CFP in the irrigation agriculture pilot areas was significantly lower than in non-reform areas.  Irrigation reforms mainly impacted the crop CFP through four intermediary effects: the project (implementation of field irrigation channels), technology (improving adoption of new irrigation technologies), management (proper irrigation operation and maintenance), and yield effects.  All effects inhibited the CFP, except for the project effect that promotes carbon emissions.  Among them, yield increase has the greatest impact on reducing CFP, followed by management and technology effects.  Furthermore, planting practices, individual characteristics, and plot quality significantly impacted the crop CFP.  This study has policy implications for understanding the food security–climate nexus in the food production industry.

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Water diversion and agricultural production: Evidence from China YANG Rui, XU Hang 2023, 22(4): 1244-1257.  DOI: 10.1016/j.jia.2023.03.006 Abstract ( )   PDF in ScienceDirect   Water diversion can alleviate water shortages caused by the uneven distribution of water resources.  China’s South-to-North Water Diversion Project (SNWD) is the largest water diversion project worldwide.  Based on the prefecture-level data of China’s Huang-Huai-Hai Plain from 2000 to 2020, this study employs an empirical strategy of Differences-in-Differences (DID) to analyze the impact of SNWD on agricultural production.  The results show that SNWD has significantly increased agricultural production, measured by the agricultural value added.  The estimated results of the benchmark model remain robust when the contemporaneous policy is addressed, an alternative outcome is used, subsamples are estimated, and alternative estimation techniques are employed.  This study argues that the potential impact mechanism may be that SNWD significantly increases the acreage for cash crops but reduces that for grain crops.  Heterogeneity analysis shows that in prefectures with high temperature or land potential, SNWD’s impact on agricultural value added is relatively low.  In contrast, in areas with prolonged sunshine or high slopes, SNWD’s impact on agricultural value added is relatively large.  Given the low added value of grain crops, the government should consider strengthening food security by subsidizing water supply to sustain grain production.

Short Communication

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Investigation of Aegilops umbellulata for stripe rust resistance, heading date, and the contents of iron, zinc, and gluten protein SONG Zhong-ping, ZUO Yuan-yuan, XIANG Qin, LI Wen-jia, LI Jian, LIU Gang, DAI Shou-fen, YAN Ze-hong 2023, 22(4): 1258-1265.  DOI: 10.1016/j.jia.2022.08.014 Abstract ( )   PDF in ScienceDirect   Aegilops umbellulata (UU) is a wheat wild relative that has potential use in the genetic improvement of wheat.  In this study, 46 Ae. umbellulata accessions were investigated for stripe rust resistance, heading date (HD), and the contents of iron (Fe), zinc (Zn), and seed gluten proteins.  Forty-two of the accessions were classified as resistant to stripe rust, while the other four accessions were classified as susceptible to stripe rust in four environments.  The average HD of Ae. umbellulata was significantly longer than that of three common wheat cultivars (180.9 d vs. 137.0 d), with the exception of PI226500 (138.9 d).  The Ae. umbellulata accessions also showed high variability in Fe (69.74–348.09 mg kg–1) and Zn (49.83–101.65 mg kg–1) contents. Three accessions (viz., PI542362, PI542363, and PI554399) showed relatively higher Fe (230.96–348.09 mg kg–1) and Zn (92.46–101.65 mg kg–1) contents than the others.  The Fe content of Ae. umbellulata was similar to those of Ae. comosa and Ae. markgrafii but higher than those of Ae. tauschii and common wheat.  Aegilops umbellulata showed a higher Zn content than Ae. tauschii, Ae. comosa, and common wheat, but a lower content than Ae. markgrafii.  Furthermore, Ae. umbellulata had the highest proportion of γ-gliadin among all the species investigated (Ae. umbellulata vs. other species=mean 72.11% vs. 49.37%; range: 55.33–86.99% vs. 29.60–67.91%).  These results demonstrated that Ae. umbellulata exhibits great diversity in the investigated traits, so it can provide a potential gene pool for the genetic improvement of these traits in wheat.

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Molecular epidemiological study of animal rabies in Kazakhstan Gulzhan N. YESSEMBEKOVA, XIAO Shuang, Assem ABENOV, Talgat KARIBAEV, Alexandr SHEVTSOV, Amirgazin ASYLULAN, Yersyn Y. MUKHANBETKALIYEV, SHUAI Lei, BU Zhi-gao, Sarsenbay K. ABDRAKHMANOV 2023, 22(4): 1266-1275.  DOI: 10.1016/j.jia.2022.11.011 Abstract ( )   PDF in ScienceDirect   Rabies is a serious public health issue in Kazakhstan, with high economic impact and social burden.  As part of a routine surveillance, 31 rabies-positive brain specimens taken from livestock (cattle) and carnivores (dogs, foxes, and cats) during 2013–2021 were subject to viral sequencing.  Phylogenetic and Bayesian analysis were performed using obtained rabies virus (RABV) sequences.  All 31 strains of RABV candidate belonged to the Cosmopolitan clade, of which 30 strains belonged to steppe-type subclade, and 1 dog strain belonged to Other subclade.  The 31 strains did not diverge from RABV strains in Kazakhstan and neighboring countries, including Russia, Mongolia, and China, suggesting that animal rabies has close relationship and transmission between borders.  Fox-originated strains and cattle strains shared similar sequence signature, and some animal rabies cases had space–time intersection, showing that infected foxes were a major transmission source of cattle rabies in different Kazakhstan regions.  Besides, free-roaming dogs played a pivotal role in rabies epizootics of cattle in Kazakhstan.  The recent spread of animal rabies presents an increasing threat to public health, and provides updated information for improving current control and prevention strategies at the source for Kazakhstan and neighboring countries.