All Cover Illustrations

    Volume 21, Issue 8, Aug. 2022

    Conservation agriculture (CA) practice systems have been promoted as an effective approach to achieve sustainable agricultural. The present two-year study demonstrated that major rice pests and paddy weeds were effectively controlled by reduced tillage (RT) practice compared to the conventional tillage (CT) treatment, while no tillage (NT) treatment could aggravate the incidence of some weed species. In addition, the diversity of beneficial organisms, such as the pest predators Trichogramma japonicun Ashmead, increased remarkably where either RT or NT was applied, which highlighted the significance of a CA strategy for the promotion of biodiversity in the agroecosystem. More importantly, the rice yield gradually increased after the two-year RT practice, while there was no significant difference in NT. Taken together, this study indicates that the implementation of RT practices could benefit crop protection by enhancing paddy biodiversity and improving crop yield in southern China, which provides a solid basis and novel insights for the establishment of sustainable agro-ecosystems. The cover photo shows the biodiversity of organisms and crop yield differs under three tillage management practices (CT, RT and NT) applied in the present study, which was provided by Prof. Zhong Guohua and Dr. Liu Jie from College of Plant Protection, South China Agricultural University, China. See pages 2345–2356 for more details.

    Volume 21, Issue 7, Jul. 2022

    H5N1 and H5N8 viruses bearing the clade 2.3.4.4b HA gene have been widely circulating in wild birds and are responsible for the loss of over 100 million domestic poultry in Europe, Asia, and North America since January 2020. To prevent domestic poultry from being infected with these exotic viruses, a novel trivalent vaccine with the seed viruses H5-Re13, H5-Re14, and H7-Re4 that carry the HA and NA genes of the newly detected H5N6 virus, H5N8 virus, and H7N9 virus, respectively, was developed in China. Animal studies proved that this novel H5/H7 trivalent vaccine is immunogenic and could provide solid protection against the H5N1, H5N6, H5N8, and H7N9 viruses that are currently circulating in nature. Given the sound protective efficacy of this vaccine and the wide circulation of different H5 and H7 viruses, it’s recommended that this new H5/H7 trivalent inactivated vaccine be used not only in China, but also in other countries where poultry are threatened by H5 and H7 viruses. The cover photo shows the solid protection of the vaccine against different viruses, which was provided by Prof. Chen Hualan from Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, China. See pages 2086–2094 for more details.

    Volume 21, Issue 6, Jun. 2022

    Strawberry (Fragaria×ananassa), known as ‘the queen of fruits’, is very popular with consumers due to its flavor and nutritional value.  WRKY transcription factors play a critical role in biotic and abiotic stress responses in plants.  Based on the cultivated strawberry ‘Camarosa’ genome, 222 FaWRKY genes were identified and analyzed.  Meanwhile, FaWRKY genes participate in regulating the growth and development of different tissues and fruit ripening stages.  In addition, FaWRKY expression profiles were also studied in the strawberry seedlings inoculated with Colletotrichum fructicola, a major pathogen of strawberry.  The photo shows the fruits of the new strawberry cultivar ‘Shenxin’, which was provided by Dr. Zou Xiaohua from Shanghai Academy of Agricultural Sciences, China. See pages 1658–1672 for more details. 

    Volume 21, Issue 5, May 2022

    Pea aphid (Acyrthosiphon pisum) is a destructive insect pest of multiple leguminous plants, it is widely used as a research model for investigating interactions between insects and their host plants. A highly conserved odorant receptor clade among different aphid species was identified by phylogenetic analysis. One of this clade member ApisOr23 in A. pisum had the highest expression level in the antennae compared to other tissues. Functional characterization of ApisOr23 using a heterologous Xenopus expression system revealed that ApisOr23 was broadly tuned to plant volatiles, in which trans-2-hexen-1-al, one of the main volatile organic compounds released from legume plants, activated the highest response of ApisOr23. The results suggest that the conserved Or23 clade in most aphid species might play an important role in host plant detection. The cover photo shows two pea aphids (A. pisum) colonize on the broad bean (Vicia faba) through detecting plant volatiles by antennae, which was provided by Dr. LIU Lei from Institute of Plant Protection, Chinese Academy of Agricultural Sciences. See pages 1414–1423 for details.

    Volume 21, Issue 4, Apr. 2022

    Rice (Oryza sativa L.) is one of the most important food crops in the world, providing nearly 60% of the dietary calories for more than 3 billion people. A major challenge in rice production is to achieve the dual goal of increasing grain yield and nitrogen (N) use efficiency (NUE). The adoption of N-efficient rice varieties (NEVs) is an important approach to achieve the dual goal. It is observed that, in comparison with N-inefficient rice varieties, NEVs produce both higher grain yield and higher NUE, due mainly to a larger sink size resulted from a larger panicle (more spikelets per panicle), higher N dry matter production efficiency (dry matter weight/N uptake) and higher harvest index. The NEVs also exhibit better leaf photosynthetic performance including higher specific leaf weight, greater leaf photosynthetic rate, and higher contents of ribulose-1,5-bisphosphate carboxylase/ oxygenase and chlorophyll in leaves. Furthermore, NEVs show a better canopy structure, which is reflected by a higher ratio of the extinction coefficient for effective leaf N to the light extinction coefficient. All these observations indicate that improved source and sink traits and coordinated source–sink relationship contribute to higher grain yield and higher NUE of NEVs. The cover photo shows the NEV with larger sink size and better leaf photosynthetic performance, which was provided by the Rice Cultivation and Physiology Innovation Team, College of Agriculture, Yangzhou University, China. See pages 947–963 for details

    Volume 21, Issue 3, Mar. 2022

    Ponkan (Citrus reticulata Blanco) is one of the most widely grown citrus species in China due to its elite palatability, strong flavor and good storability. The size and quality of Ponkan fresh fruit are two crucial factors determining its marketing and consumer preference. Various approaches have been employed to improve the fruit size and quality, including manual fruit thinning. Manual fruit thinning was found to increase the proportion of fruit with larger size and elevate the total soluble solids, leading to substantially improved fruit quality. Meanwhile, the fruits from the thinned trees exhibited higher mRNA abundance of sugar transporters, auxin and gibberellin biosynthesis or signaling genes. Therefore, manual fruit thinning could greatly improve fruit quality by promoting fruit expansion due to the increased auxin levels and expediting sugar accumulation through the up-regulation of sugar transporter genes. The cover photo shows the Ponkan fruits with favorable external appearance and internal fruit quality, which was provided by Prof. Liu Jihong from Huazhong Agricultural University, China. See pages 725–735 for more details.

    Volume 21, Issue 2, Jan. 2022

    China is currently undergoing a critical transformation from traditional to modern agriculture. The development of the corn industry urgently requires vital technologies such as mechanical grain harvesting, which can save labor and cost, reduce losses, and raise quality, thus known as the “last mile” of the whole mechanization process of corn production. However, foreign technology was difficult to apply directly in China’s main corn-producing areas, characterized by intricate climatic conditions, diverse planting patterns, and small-scale households. In recent years, corn cultivars suitable for mechanical grain harvesting have been developed, promoted, and gradually reached full-adoption. This has led to harvesting machinery improvements and other technological advances such as the creation of cultivar characteristics catered to regional climatic resources, innovation in cultivation management, and storage and drying facility upgrades. In different regions of China, the adoption of mechanical grain harvesting technology has significantly improved grain quality, and a series of local standards for this technology have been formulated and publicized. For example, “high-efficiency production technology for mechanical grain harvesting of corn” was listed by the Ministry of Agriculture and Rural Affairs as one of the “New Rural Technologies of Chinese Agriculture” in 2020. For the time being, the preliminary development of mechanical corn harvesting technology has been completed, and it is expected to enter a stage of rapid growth. In the coming time, mechanical harvesting, as presently done for wheat and rice, will become a standard practice for corn in China. The photo was provided by the Crop Cultivation and Physiology Innovation Team of the Chinese Academy of Agricultural Sciences.

    Volume 21, Issue 1, Jan. 2022

    The most recent breakthrough in agricultural biotechnology is the introduction of RNAi-mediated strategy to control insect pests, either by transgenic crops expressing insecticidal dsRNAs/siRNAs or RNA pesticides. There is a highly demand to develop a reliable risk evaluation method on the potential off-targets effect of this novel technique. The cover photos showed the larvae of the beet armyworm (Spodoptera exigua) (left), a widely distributed polyphagous pest of both food and economic crops worldwide and the management of this pest insect continues to rely on synthetic chemical insecticides nowadays. The non-target organism, the silkworm (Bombyx mori) (right), is a widely used species in the safety evaluation of agricultural techniques against insect pest. These pictures were provided by Mr. Xiong Kaifan from Huazhong Agricultural University, China and Dr. Li Muwang from Jiangsu University of Science and Technology, China. See pages 170–177 for details.

    Volume 20, Issue 12, Dec. 2021

    Bacterial panicle blight of rice (BPBR), also known as bacterial grain rot of rice, is a serious seed borne disease of rice caused by Burkholderia glumae. Because the optimal temperature range for the growth of B. glumae is relatively high (30–35°C), it is considered that this disease may occur more frequently with current global climate change. Horizontal gene transfer (HGT), also known as lateral gene, has been proved a major driving force in prokaryotic evolution. However, the molecular functions of these transferred genes in pathogenic bacteria especially plant pathogenic bacteria are still not fully investigated. In this study, the whole-genome in silico analysis was performed and found a syringopeptin synthetase (syp) homolog in B. glumae, which can cause bacterial panicle blight in rice, was predicted to be horizontally transferred from Pseudomonas ancestor with solid confidence by phylogenetic analysis. Inoculation of rice panicles with the syp mutant resulted in 60% lower disease index compared with the wild type (WT) parent strain, suggesting the requirement of syp for the full virulence of B. glumae. Chromatography analysis of exudates from B. glumae showed suppression of synthesis of metabolites analogous to syringopeptin in the mutants. All these data raise the possibility of HGT phenomenon in shaping the virulence and adaptation of B. glumae over evolutionary time. The photos are provided by the research team of Prof. Zhu Bo from Shanghai Jiao Tong University, China. See pages 3222–3229 for details.

    Volume 20, Issue 11, Nov. 2021

    Cotton is an important economic crop in China and plays a vital role in improving farmers’ income. In recent years, cotton planting areas have dropped rapidly in China because of high labor cost and low profit. Defoliation is an indispensable step in cotton production with mechanical harvesting, especially in the North China Plain (NCP) where mechanical harvesting is limited by a large proportion of green leaves and unopened bolls at harvest time due to insufficient thermal resources. The goal of this study was to quantify the optimal use of defoliation products while minimizing yield and quality loss in China. The findings would offer valuable guidance for the management of cotton production, promote cotton mechanical harvesting and reduce the labor cost of cotton production in China. The pictures were provided by Engineering Research Center of Plant Growth Regulator, Ministry of Education/College of Agronomy and Biotechnology, China Agricultural University, China. See pages 2892–2899 for details.

    Volume 20, Issue 10, Oct. 2021

    The cultivated strawberry (Fragaria×ananassa) is the most economically important soft fruit species globally and always ranks first in cultivation area and yield harvest among small berries. The quality of strawberry is mainly determined by the content and variety of soluble sugars, and their accumulation during the maturation process largely determines flavor and sweetness at harvest. High sugar levels accumulate in the fruit depending on the expression of various genes associated with sugar biosynthesis, metabolism, and transportation. Invertases (INVs) play an important role in the regulation of sugar accumulation because they irreversibly catalyse the hydrolysis of sucrose into the corresponding nucleoside diphosphate-glucose, glucose or fructose in fruit. Due to the heterozygosity and complexity of the polyploid genome, research on the function of invertase genes has been especially limited in octoploid strawberry (Fananassa). In this work, we provided a comprehensive analysis of the INV gene family in octoploid strawberry (Fananassa), including the gene structure, chromosomal locations, conserved domains, and gene evolution and expression profiles during strawberry fruit development. Our study revealed that polyploid events resulted in the abundant amplification (almost three- or four-fold) of the INV gene in the F.×ananassa genome, these amplified INV genes showed dominant expression in strawberry fruit and FaCWINV1 may be involved in sugar accumulation in strawberry fruit. The photos are provided by the research team of Prof. Zhao Mizhen from Jiangsu Academy of Agricultural Sciences, China. See pages 2652–2665 for details.

    Volume 20, Issue 9, Sept. 2021

    Birth weight (BW) and days to 100 kg (D100) are important economic traits that are both affected by polygenes. The genetic architecture of these quantitative traits is still poorly understood. The BW and D100 are highly correlated and may be controlled by common genes. However, no study investigates the common loci and genes shared by BW and D100. Comparing to the low chip data, genotyping-by-sequencing (GBS) data containing a large number of single nucleotide polymorphisms (SNPs) have become a powerful tool for exploring the genetic mechanisms of quantitative traits. To identify the common genetic variants and candidate genes that contribute to the phenotypic variability of BW and D100, this study conducted a GWAS for BW and D100 using GBS data of 600 purebred Yorkshire pigs. Particularly, one locus located on SSC12 (position: 46 226 512 bp) was evaluated to affect both BW and D100 in Yorkshire pigs, indicating the pleiotropism in different traits. The NSRP1 and DOCK7 genes were identified as the most promising candidate genes involved in growth traits. Use of GBS is able to identify novel variants for BW and D100, and provide an opportunity for improving pig growth traits using genomic selection in pigs. The photo, provided by Prof. Tang Guoqing from the Sichuan Agricultural University, China, shows the significant loci and characteristics of Yorkshire pigs. See pages 2483–2490 for details.

    Volume 20, Issue 8, Aug. 2021

    Fusarium graminearum is a predominant causal agent of Fusarium head blight (FHB) or scab on staple food crops including wheat, barley and maize in most growing areas. In addition to severe yield and economic losses, F. graminearum produces mycotoxins such as deoxynivalenol (DON) and zearalenone (ZEA) in the infected grains, which pose serious threats to human and animal health. Due to the lack of highly efficient disease-resistant cultivars, fungicides play a prominent role of reliable FHB management. However, with the development of resistance against fungicides, the efficiency of chemical control has been adversely affected. In order to establish efficient management strategies, a clear understanding of the pathogenesis of this devastating fungus seems particularly important. Nutrient and stress factor 1 (Nsf1), a transcription factor containing the classical Cys2-His2 (C2H2) zinc finger motif, is expressed under non-fermentable carbon conditions and in response to salt stress in Saccharomyces cerevisiae. However, the role of Nsf1 in filamentous fungi is not well understood. In this study, the orthologue of Nsf1 was investigated in F. graminearum (named FgNsf1), and the roles of FgNsf1 were elucidated by constructing a deletion mutant and its functional complementation mutant. The photo, provided by Prof. Chen Changjun from the Nanjing Agricultural University, China, shows the symptoms of FHB in the field induced by F. graminearum. See pages 2156–2169 in details.

    Volume 20, Issue 7, Jul. 2021

    Tomato brown rugose fruit virus (ToBRFV) is a new emerging tobamovirus and causes serious threat to the tomato industry. Since it was firstly reported by Jordan in 2015, ToBRFV has spread to America, Asia, and Europe. The photo, provided by Prof. Li Xiangdong from the Shandong Agricultural University, China, shows the brown rugose necrotic lesion symptoms induced by ToBRFV on tomato fruits. See pages 1871–1879 in details.

    Volume 20, Issue 6, Jun. 2021

    The goal of this special focus is to shed light on a new research topic on high quality, efficient and precise fertilization of rice. The findings offer valuable guidance and reference for the management of high quality and high efficiency nitrogen fertilizers for rice. The cover image is a combination of the single fertilization technology of controlled release blended fertilizer for machine-transplanted rice. The pictures were provided by the Rice Cultivation Team of Nanjing Agricultural University, China.

    Volume 20, Issue 5, May 2021

    Livestock and poultry manure, crop straw and agricultural products processing waste are the main agricultural solid wastes. The resource usage of these wastes through transformation of microorganisms and some insects will be very important to sustainable development of agriculture. However, the factors influencing insect or microorganism conversion processes are still lacking. Therefore, this special focus addresses the dynamics of microbial diversity and changes in bioavailability of heavy metals during the conversion of wastes by microorganisms or insects. Cover photos were provided by Prof. Li Zhaojun (Chinese Academy of Agricultural Sciences) and Prof. Li Rong (Nanjing Agricultural University, China).