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Effect of high-molecular-weight glutenin subunit Dy10 on wheat dough properties and end-use quality

WANG Yan, GUO Zhen-ru, CHEN Qing, LI Yang, ZHAO Kan, WAN Yong-fang, Malcolm J. HAWKESFORD, JIANG Yun-feng, KONG Li, PU Zhi-en, DENG Mei, JIANG Qian-tao, LAN Xiu-jin, WANG Ji-rui, CHEN Guo-yue, MA Jian, ZHENG You-liang, WEI Yu-ming, QI Peng-fei

2023, 22 (6): 1609-1617. DOI: 10.1016/j.jia.2022.08.041

Abstract （423） PDF in ScienceDirect

High-molecular-weight glutenin subunits (HMW-GSs) are the most critical grain storage proteins that determine the unique processing qualities of wheat. Although it is a part of the superior HMW-GS pair (Dx5+Dy10), the contribution of the Dy10 subunit to wheat processing quality remains unclear. In this study, we elucidated the effect of Dy10 on wheat processing quality by generating and analyzing a deletion mutant (with the Dy10-null allele), and by elucidating the changes to wheat flour following the incorporation of purified Dy10. The Dy10-null allele was transcribed normally, but the Dy10 subunit was lacking. These findings implied that the Dy10-null allele reduced the glutenin:gliadin ratio and negatively affected dough strength (i.e., Zeleny sedimentation value, gluten index, and dough development and stability times) and the bread-making quality; however, it positively affected the biscuit-making quality. The incorporation of various amounts of purified Dy10 into wheat flour had a detrimental effect on biscuit-making quality. The results of this study demonstrate that the Dy10 subunit is essential for maintaining wheat dough strength. Furthermore, the Dy10-null allele may be exploited by soft wheat breeding programs.

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Identification of soft rot resistance loci in Brassica rapa with SNP markers

LIU Meng-yang, WU Fang, GE Yun-jia, LU Yin, ZHANG Xiao-meng, WANG Yan-hua, WANG Yang, YAN Jing-hui, SHEN Shu-xing, ZHAO Jian-jun, MA Wei

2022, 21 (8): 2253-2263. DOI: 10.1016/S2095-3119(21)63874-1

Abstract （221） PDF in ScienceDirect

Soft rot caused by Pectobacterium carotovorum (Pc) is a devastating disease of Brassica rapa, causing substantial reductions in crop yield and quality. Identifying genes related to soft rot resistance is the key to solving this problem. To characterize soft rot resistance, we screened a soft rot-susceptible Chinese cabbage (A03), a resistant pakchoi (‘Huaguan’), and a resistant mutant (sr). An F₂ population was generated by crossing susceptible Chinese cabbage A03 and resistant pakchoi ‘Huaguan’ to identify quantitative trait loci (QTLs) that confer soft rot resistance. A high-density genetic map was constructed and the three QTLs identified contain 166 genes. Based on available transcriptome data, we analyzed the expression of the 166 genes during an important defense regulatory period in Pc infection in both A03 and the resistant mutant sr. Among the 166 genes, six candidate genes were related to the soft rot defense response in B. rapa. TIFY10B (JAZ2, BraA07g038660.3C) was located in the major soft rot resistance QTL, DRQTL-3 on A07, and we speculate that this gene may play an important role in the defense mechanism against soft rot in B. rapa. This study lays the foundation for further investigations on the mechanism of soft rot resistance in B. rapa crops.

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An economic and viable approach to improve wheat quality in Qinghai–Tibetan Plateau, China

WANG Yu-jiao, TAO Zhi-qiang, WANG De-mei, WANG Yan-jie, YANG Yu-shuang, ZHAO Guang-cai, SHI Shu-bing, CHANG Xu-hong

2022, 21 (8): 2227-2240. DOI: 10.1016/S2095-3119(21)63677-8

Abstract （156） PDF in ScienceDirect

Wheat flour products are the main dietary component of the Qinghai–Tibetan Plateau (QTP) population in China. However, the high altitude restricts the local wheat quality and quantity, and the applied nitrogen rate is higher than the optimal rate for wheat planting. In this study, we considered whether reducing the amount of nitrogen fertilizer and introducing the superior varieties from the North China Plain (NCP) are viable ways to increase the wheat quality and quantity in the QTP. Three and four winter wheat cultivars from QTP and NCP, respectively, were planted in Lhasa at an altitude of 3 647 m with reduced topdressing nitrogen application at the jointing stage. The wheat from NCP exhibited higher grain hardness index and test weight, and better flour and dough quality. Reducing the topdressing nitrogen fertilizer from 135 to 75 kg N ha⁻¹ at the jointing stage (with the same basal fertilization of 105 kg N ha⁻¹) did not significantly (P<0.05) affect the grain yield, grain quality, flour quality or dough quality in any of the cultivars. In summary, introducing high-quality winter wheat varieties from the NCP to the Lhasa plateau is a viable way to enhance the wheat supply and quality in the QTP. Reducing a certain amount of the nitrogen fertilizer is an economic and feasible approach for the QTP region.

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Protective efficacy of an H5/H7 trivalent inactivated vaccine (H5-Re13, H5-Re14, and H7-Re4 strains) in chickens, ducks, and geese against newly detected H5N1, H5N6, H5N8, and H7N9 viruses

ZENG Xian-ying, HE Xin-wen, MENG Fei, MA Qi, WANG Yan, BAO Hong-mei, LIU Yan-jing, DENG Guo-hua, SHI Jian-zhong, LI Yan-bing, TIAN Guo-bin, CHEN Hua-lan

2022, 21 (7): 2086-2094. DOI: 10.1016/S2095-3119(22)63904-2

Abstract （761） PDF in ScienceDirect

Some H5 viruses isolated in poultry or wild birds between 2020 and 2021 were found to be antigenically different from the vaccine strains (H5-Re11 and H5-Re12) used in China. In this study, we generated three new recombinant vaccine seed viruses by using reverse genetics and used them for vaccine production. The vaccine strain H5-Re13 contains the hemagglutinin (HA) and neuraminidase (NA) genes of an H5N6 virus that bears the clade 2.3.4.4h HA gene, H5-Re14 contains the HA and NA genes of an H5N8 virus that bears the clade 2.3.4.4b HA gene, and H7-Re4 contains the HA and NA genes of H7N9 virus detected in 2021. We evaluated the protective efficacy of the novel H5/H7 trivalent inactivated vaccine in chickens, ducks, and geese. The inactivated vaccine was immunogenic and induced substantial antibody responses in the birds tested. Three weeks after vaccination, chickens were challenged with five different viruses detected in 2020 and 2021: three viruses (an H5N1 virus, an H5N6 virus, and an H5N8 virus) bearing the clade 2.3.4.4b HA gene, an H5N6 virus bearing the clade 2.3.4.4h HA gene, and an H7N9 virus. All of the control birds shed high titers of virus and died within 4 days post-challenge, whereas the vaccinated chickens were completely protected from these viruses. Similar protective efficacy against H5 viruses bearing the clade 2.3.4.4h or 2.3.4.4b HA gene was observed in ducks and geese. Our study indicates that the newly updated H5/H7 vaccine can provide solid protection against the H5 and H7N9 viruses that are currently circulating in nature.

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The expression, function, and coding potential of circular RNA circEDC3 in chicken skeletal muscle development

WEI Yuan-hang, ZHAO Xi-yu, SHEN Xiao-xu, YE Lin, ZHANG Yao, WANG Yan, LI Di-yan, ZHU Qing, YIN Hua-dong

2022, 21 (5): 1444-1456. DOI: 10.1016/S2095-3119(21)63826-1

Abstract （189） PDF in ScienceDirect

As an emerging class of non-coding transcripts, circular RNAs (circRNAs) are proved to participate in the complex process of myogenesis in diverse species. A previous study has identified circular RNA EDC3 (circEDC3) as a typical covalently closed circular RNA abundant in chicken skeletal muscle. This study found that circEDC3 is a conservative circular RNA and performed functional analysis to investigate the role of circEDC3 in chicken muscle growth. The results indicated that circEDC3 could inhibit (P<0.05) chicken skeletal muscle satellite cells (SMSCs) proliferation and differentiation but had no significant influence on SMSCs apoptosis. Additionally, bioinformatics analysis showed that circEDC3 had promising coding potential. The open reading frames (ORF) were found in circEDC3 in this study. Furthermore, this study predicted that circEDC3 had internal ribosome entry sites (IRES) and N6-methyladenosine (m6A) motifs in different species, implying that circEDC3 might be translatable. This study revealed that circEDC3 might be a negative regulator in chicken muscle development and suggested it has protein-coding potential in different species.

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Tissue distribution and changes in dopamine during development and stress responses in Malus germplasm

ZHANG Zhi-jun, ZHANG Jing, TANG Zhong-wen, WANG Yan-peng, GAO Teng-teng, LIU Xiao-min, MA Feng-wang, LI Chao

2022, 21 (3): 710-724. DOI: 10.1016/S2095-3119(20)63590-0

Abstract （193） PDF in ScienceDirect

Dopamine is a catecholamine and an anti-oxidant which functions in responses to stress and it interacts with plant hormones to mediate plant development. At present, there are few studies on the functions of dopamine in apple. This study developed a method for dopamine determination which was used to analyze dopamine in Malus germplasm, in order to clarify the tissue distribution, developmental changes, diurnal variations, and stress responses in apple trees. First, the proposed method was verified. The linear range of quantification was robust from 0.1 to 20 ng mL^–1. The instrumental, inter-day precision, and sample repeatability relative standard deviations were 1.024, 5.607, and 7.237%, respectively. The spiked recovery was greater than 100%, indicating the feasibility of the method and its suitability for the rapid analysis of dopamine in Malus. Next, the dopamine content was measured in 322 Malus tissues. The results showed that the dopamine level in Malus was low and the average dopamine content in leaf was higher than in peel and flesh. The dopamine had a skewed distribution that deviated to the right in cultivars and wild accessions. Finally, the tissue specificity, developmental changes, diurnal changes, and responses to stress were analyzed. In cultivar ‘Pinova’ (Malus domestica), the dopamine concentration was the highest in leaf buds and lowest in flesh. The dopamine contents in leaf and flesh decreased with the growth and development of cultivar ‘Liangxiang’ (Malus domestica). The dopamine content of apple leaves was higher after either drought or salinity stress as compared to the control. In this study, a dopamine detection method for apple was established based on HPLC-MS and shown to be a robust approach. This study provides a framework for future research on elucidating the tissue distribution, developmental changes, diurnal variation, and stress responses of dopamine in apple trees.

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Diamide derivatives containing a trifluoromethylpyridine skeleton: Design, synthesis, and insecticidal activity

XU Fang-zhou, WANG Yan-yan, GUO Sheng-xin, DAI A-li, WU Jian

2022, 21 (10): 2995-3003. DOI: 10.1016/j.jia.2022.07.046

Abstract （191） PDF in ScienceDirect

Diamide derivatives are biologically active molecules that have been widely applied in recent years in research on pesticides, especially insecticides. Using a simple and environmentally friendly scheme, a series of new diamide derivatives containing a trifluoromethylpyridine skeleton was designed, synthesized, and confirmed by ¹H,¹⁹F and ¹³C NMR, and HR-MS. Their insecticidal activities against Plutella xylostella and Helicoverpa armigera were measured and the relationship between structure and activity was investigated. Eight of the title compounds (D2, D5, D10, D21, D28, D29, D30 and D33) showed 100% activity against P. xylostella at 500 mg L^–1. One compound, D33, still showed 100% activity against P. xylostella at 100 mg L^–1 and had the lowest LC₅₀ (lethal concentration 50%, 3.7 mg L^–1) among the synthesized compounds. Molecular docking analysis revealed that D33 could be thoroughly embedded in the active pocket of the ryanodine receptor via hydrogen bonding in a manner similar to the commercial insecticide chlorantraniliprole.

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Physiological response of flag leaf and yield formation of winter wheat under different spring restrictive irrigation regimes in the Haihe Plain, China

LIU Xue-jing, YIN Bao-zhong, HU Zhao-hui, BAO Xiao-yuan, WANG Yan-dong, ZHEN Wen-chao

2021, 20 (9): 2343-2359. DOI: 10.1016/S2095-3119(20)63352-4

Abstract （158） PDF in ScienceDirect

In order to identify the optimum period of spring water-restrictive irrigation for winter wheat (Triticum aestivum L.) in the Haihe Plain, China and elucidate its effects on flag leaf senescence and yield formation, field experiments were conducted at the Xinji Experimental Station of Hebei Agricultural University from 2016 to 2019 by using different irrigation regimes in spring, including the conventional regime involving two irrigation periods (control (CK), the 3-leaf unfolding stage and the anthesis stage) and a series of single, restrictive irrigation regimes (SRI) comprising irrigation at the 3-leaf unfolding stage (3LI), 4LI, 5LI, and 6LI. There are five major findings: (1) The senescence (determined by the green leaf area, GLA) in the 4LI treatment occurred moderately earlier than that in CK, showed no significant difference with that in 5LI and 6LI, and occurred significantly later than that in 3LI. (2) Compared with other SRI treatments, the GLA value and photosynthetic rate in 4LI were 14.82 and 20.1% higher, respectively. Microstructural analysis of flag leaf also revealed that the mesophyll cells and chloroplasts were irregularly arranged under drought stress in 3LI and 6LI; however, drought stress had minimal negative effects on the microstructure in 4LI and 5LI. (3) Postponed irrigation in spring could significantly increase superoxide dismutase (SOD) and catalase (CAT) activities in the early stage of grain filling; however, these activities would subsequently decrease. Among the four SRI treatments, the overall enzyme activities were the highest in 4LI, and the combined malondialdehyde (MDA) content in flag leaves in 4LI and 5LI was 14.5% lower on average than that in 3LI and 6LI. (4) The soluble sugar (SS) and proline (Pro) contents in 4LI were the highest among the four SRI treatments; however, they were lower than those in CK. The abscisic acid (ABA) hormone content in 4LI and 5LI was lower than that in 3LI and 6LI, respectively, suggesting a smaller drought stress effect in 4LI and 5LI. (5) In two growing seasons, there was a larger number of spikes per unit area in 4LI (i.e., 13.4% higher than that in 5LI and 6LI) and the 1 000-grain weight in 4LI was the highest among the four SRI treatments (i.e., 6.0% higher than that in the other three SRI treatments). Therefore, a single restrictive irrigation regime at the 4-leaf unfolding stage is recommended to be effective in slowing down the senescence process of flag leaves and achieving high yield.

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The TaFIM1 gene mediates wheat resistance against Puccinia striiformis f. sp. tritici and responds to abiotic stress

SHI Bei-bei, WANG Juan, GAO Hai-feng, ZHANG Xiao-juan, WANG Yang, MA Qing

2021, 20 (7): 1849-1857. DOI: 10.1016/S2095-3119(20)63276-2

Abstract （144） PDF in ScienceDirect

Fimbrin, a regulator of actin cytoskeletal dynamics that participates in numerous physiological and biochemical processes, controls multiple developmental processes in a variety of tissues and cell types. However, the role of fimbrin in pathogen defense of wheat and the mechanisms have not been well studied. Here, we investigated that the expression of TaFIM1 gene of wheat was significantly induced in response to avirulent race of Puccinia striiformis f. sp. tritici (Pst) and silencing of TaFIM1 by virus-induced gene silencing method. The results show that silencing of TaFIM1 resulted in a reduction of resistance against the stripe rust indicated by both phenotypes and a histological examination of Pst growth. Additionally, the expression level of TaFIM1 gene was up-regulated under abiotic stresses. These findings suggest that TaFIM1 functions as a positive regulator of pathogen resistance of wheat plants and response to abiotic stress. Our work may show new light on understanding the roles of fimbrin in wheat.

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Genome-wide identification and expression profiling of MYB transcription factor genes in radish (Raphanus sativus L.)

Everlyne M’mbone MULEKE, WANG Yan, ZHANG Wan-ting, XU Liang, YING Jia-li, Bernard K. KARANJA, ZHU Xian-wen, FAN Lian-xue, Zarwali AHMADZAI, LIU Li-wang

2021, 20 (1): 120-131. DOI: 10.1016/S2095-3119(20)63308-1

Abstract （200） PDF in ScienceDirect

Radish (Raphanus sativus L.), an important root vegetable crop of the Brassicaceae family, has a high level of anthocyanin accumulation in its pigment root tissues. It was reported that MYB transcription factors (TFs) play vital roles in plant development and anthocyanin metabolism, and the PAP1/2 could promote expression of anthocyanin biosynthesis genes. In this study, a total of 187 radish MYB genes (RsMYBs) were identified in the radish genome and clustered into 32 subfamilies. Among them, 159 RsMYBs were localized on nine radish chromosomes. Interestingly, 14 RsMYBs exhibited differential expression profiles in different taproot developmental stages among four differently colored radish lines. A number of RsMYBs were highly expressed in the pigmented root tissues at the maturity stage, several genes including RsMYB41, RsMYB117, and RsMYB132 being homologous to PAP1/2, showed high expression levels in the red skin of NAU-YH (red skin-white flesh) taproot, while RsMYB65 and RsMYB159 were highly expressed in the purple root skin of NAU-YZH (purple skin-red flesh), indicating that these RsMYBs might positively regulate the process of anthocyanin accumulation in radish taproot. These results would provide valuable information for further functional characterization of RsMYBs, and facilitate clarifying the molecular mechanism underlying anthocyanin biosynthesis in radish.

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Regulation of the phytotoxic response of Arabidopsis thaliana to the Fusarium mycotoxin deoxynivalenol

WANG Yan, YAN Hao, WANG Qi, ZHENG Ran, XIA Kai, LIU Yang

2020, 19 (3): 759-767. DOI: 10.1016/S2095-3119(19)62741-3

Abstract （132） PDF in ScienceDirect

Phytopathogenic fungi, such as Fusarium spp., synthesize trichothecene family phytotoxins. The type B trichothecene, namely deoxynivalenol (DON), is highly prevalent in small-grain cereals, such as wheat, corn and barley. DON is thought to be a virulence factor allowing plant infections and has an elicitor activity. We used the model plant Arabidopsis thaliana to evaluate the phytotoxic effects of DON in host plants. The growth of A. thaliana on media was significantly inhibited by DON. Moreover, DON induced cell death in detached leaves was observed by trypan blue staining. This is consistent with the phenomenon of organelle changes observed at the ultrastructural level. In our study, DON exposure stimulated oxidative bursts in the leaves, resulting in the concomitant down-regulation of antioxidant enzyme defense responses and up-regulation of lipid peroxidation. In addition, a real-time PCR analysis revealed that the DON treatment rapidly induced the transcription of defense genes, like AtrbohC and AtrbohD, and up-regulated the transcriptional level of the ascorbic acid peroxidase gene. These results suggested that DON phytotoxicity might result from reactive oxygen species pathways, and that DON production by the plant pathogen Fusarium graminearum can act as an elicitor influencing plant cell fate.

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Influence of surface ozone on crop yield of maize in China

YI Fu-jin, FENG Jia-ao, WANG Yan-jun, JIANG Fei

2020, 19 (2): 578-589. DOI: 10.1016/S2095-3119(19)62822-4

Abstract （118） PDF in ScienceDirect

This study investigated the adverse effect of surface ozone on the maize yield using a unique panel from 880 counties in China. To identify the impact of elevated surface ozone concentrations, we constructed an econometric model by controlling the impact of climate variables and related economic variables. This study also considered the potential spatial correlation in the measurement of the impact of surface ozone on maize yield. Results confirmed that the increase of ozone concentration decreased the maize yield. Moreover, maize was found to be the most sensitive to ozone at the end of the second month of the growing season. The average annual loss of maize caused by ozone pollution is about 4.234 million tons in 2013–2015, accounting for 1.9% of the average output.

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Exploiting push-pull strategy to combat the tea green leafhopper based on volatiles of Lavandula angustifolia and Flemingia macrophylla

HAN Shan-jie, WANG Meng-xin, WANG Yan-su, WANG Yun-gang, CUI Lin, HAN Bao-yu

2020, 19 (1): 193-203. DOI: 10.1016/S2095-3119(19)62778-4

Abstract （181） PDF in ScienceDirect

Thirteen volatile compounds were identified from Flemingia macrophylla plants. Eight major components significantly attracted the tea green leafhoppers, Empoasca flavescens F. Based on their relative abundances, following synthetic blends were made for field experiments: 1) eight-component-attractant blend included Z-3-hexen-1-ol, Z-3-hexenyl acetate, Z-ocimene, MeSA, Z-3-hexenyl butyrate, dodecane, hexadecane and nonanal at 10, 10, 1, 11, 2, 6, 2 and 4 mg mL^–1 in n-hexane, respectively; 2) four-component-attractant blend #1 contained hexadecane, Z-3-hexenyl acetate, Z-3-hexen-1-ol and nonanal at 2, 10, 10 and 4 mg mL^–1 in n-hexane, respectively; 3) four-component-attractant blend #2 contained hexadecane, Z-3-hexenyl acetate, Z-3-hexen-1-ol and MeSA at 2, 10, 10 and 11 mg mL^–1 in n-hexane, respectively. Thymol and 1-methoxy-4-methyl-2-(1-methylethyl)-benzene, identified from Lavandula angustifolia aeration samples, significantly repelled the leafhopper as strong repellents when tested alone or in combination at 10 mg mL^–1. For field bioassays, each attractant lure was attached to a bud green sticky board hung from a bamboo stick at above tea plant level for catching the leafhoppers, whereas the repellent dispenser was tied to a tea branch inside tea clump for pushing the leafhoppers away from tea clumps. The results showed that the eight-component-attractant blend caught similar numbers of the leafhopper as did the four-component-attractant blend #1 at about 53–79 leafhoppers/trap/day, which were significantly higher than those on the hexane-control bud green sticky boards. Average leafhopper catches from un-baited sticky boards were about 51–73 leafhoppers/trap/day when pushed by the repellents placed inside tea plants, with the two-component-repellent blend being more effective than their single components. When the two-component-repellent blend was further tested with the three attractant blends in a push-pull fashion, average trap catches ranged from 62 to 92 leafhoppers/trap/day. Control efficacy on the leafhoppers within the push-pull zones increased progressively from day 1 (43%) to day 5 (73%). This push-pull approach might have a great potential as a green control strategy for combating the tea green leafhoppers.

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Domestication and breeding changed tomato fruit transcriptome

LIU Dan, YANG Liang, ZHANG Jin-zhe, ZHU Guang-tao, Lü Hong-jun, Lü Ya-qing, WANG Yan-ling, CAO Xue, SUN Tian-shu, HUANG San-wen, WU Yao-yao

2020, 19 (1): 120-132. DOI: 10.1016/S2095-3119(19)62824-8

Abstract （250） PDF in ScienceDirect

Tomato (Solanum lycopersicum) stress resistance and fruit total soluble solid (TSS) content have changed dramatically during selective breeding, and transcriptome variation has played a critical role in this rewiring. However, the single tomato reference genome impedes characterization of whole-transcriptome variation during domestication and breeding at the population level. Here, we constructed a pan-transcriptome of orange-stage tomato fruit, and investigated global expression presence/absence variation (ePAV) and differentially expressed genes (DEGs) based on RNA sequencing (RNA-seq) data from 399 tomato accessions. A total of 7 181 genes absent from the reference genome were identified, 6 122 of which were ePAV genes during tomato domestication and breeding including resistance genes such as late blight resistance gene PIM_DN29746_c0_g3_i1 and peroxidase P7-like gene PIM_DN30274_c0_g2_i1. In addition, 3 629 genes were significantly differentially expressed during tomato selection, among which 19 genes were associated with the reduced fruit TSS content of modern tomato cultivars, including LIN5, TIV1, and seven novel sugar transporter genes. Our results indicate that natural and artificial selection greatly shaped the tomato transcriptome, thereby altering the fruit TSS content and resistance to abiotic and biotic stresses.

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Evolution of varieties and development of production technology in Egypt wheat: A review

Kishk Abdelmageed, CHANG Xu-hong, WANG De-mei, WANG Yan-jie, YANG Yu-shuang, ZHAO Guang-cai, TAO Zhi-qiang

2019, 18 (3): 483-495. DOI: 10.1016/S2095-3119(18)62053-2

Abstract （411） PDF （1668KB）（747）

Wheat was the first crop grown in Egypt, and it remains highly important. Egypt is the largest wheat importer in the world and consumes an extensive amount of bread. It is imperative for wheat scientists to decrease the large gap between production and consumption. Wheat yields in Egypt increased 5.8-fold (6.7 billion kg) between 1961 and 2017 due to variety improvement and the use of better planting methods such as the raised bed method, ideal sowing date, surge flow irrigation and farm irrigation systems, laser levelling, fertilizers, and intercropping with raised beds. In this paper, the development of wheat production techniques and variety evolution over more than five decades in Egypt have been analyzed. In particular, we have focused on the technologies, cultural practices and causes for per unit area yield increase. The main purpose was to study the issues that have arisen during wheat production and to make recommendations for smart agricultural practices. In 1981, the yield was 3 300 kg ha^–1 and through the improvement of varieties, expansion of agricultural land and the adoption of modern agricultural techniques yield reached 6 500 kg ha^–1 by 2017. The production growth rate was 4.1% annually, and the total grain yield increased 4.3-fold, from 1.9 billion kg in 1981 to about 8.1 billion kg in 2017. The use of new improved varieties, new cultivation techniques, and modern irrigation techniques contributed to 97.0% of the increase in yield per unit area and 1.5% of the increase in yield was due to planting area expansion. Therefore, the increase in total yield mainly depended on the increase in yield per unit area. Wheat production in Egypt has been improved through the development of breeding and cultivation techniques. The use of these new techniques, the popularization of new high-quality seed varieties, and the use of the raised bed method instead of the old method of planting in basins have made the largest contributions to increased yield. In the future, wheat yield could be further increased by using the tridimensional uniform sowing mode and the development of wheat varieties that are resistant to rusts, deficit irrigation, and abiotic stress, that are highly adaptable to mechanized operation and have high yields. Based on our analysis, we propose the main technical requirements and measures to increase wheat yield in Egypt in the near future.

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Understanding the metabolism of Mycoplasma mycoides subsp. capri in vitro by a transcriptomic analysis

WANG Xiao-hui, WANG Yan-fang, HUANG Hai-bi, BAI Fan, SHI Xiao-na, MA Chang-jiao, GAO Yuan, ZHANG Jian-hua, ZHANG Wen-guang, HAO Yong-qing

2018, 17 (2): 428-435. DOI: 10.1016/S2095-3119(17)61747-7

Abstract （797） PDF in ScienceDirect

It is generally known that the culture for mycoplasma is time-consuming and a variety of nutrients are needed in the culture medium. This brings a lot of difficulties to mycoplasma research and application, including Mycoplasma mycoides subsp. capri (Mmc). Furthermore, little research on the characteristics of Mmc metabolism has been reported. In this study, Mmc PG3 strain cultures were investigated for dynamic gene expression. Culture samples were harvested during logarithmic phase (PG3-1), stationary phase (PG3-2), decline phase (PG3-3) and late decline phase (PG3-4). Twelve RNA samples (three replicates for each of the four growth stages considered) from these cultures were collected and sequenced. Paired comparison between consecutive growth phases in the four growth stages showed 45 significant differentially expressed genes (P<0.01) were linked to PG3 metabolism. The enzymes these genes coded were mainly involved in ATP synthase, pyrimidine metabolism, nicotinate and nicotinamide metabolism, arginine and proline metabolism. Among these, cytidylate kinase, fructose 1,6-bisphosphate aldolases Class II, nicotinate-nucleotide adenylyltransferase and dihydrolipoamide dehydrogenase play a key role in Mmc metabolism. These results provide a baseline to build our understanding of the metabolic pathway of Mmc.

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Effects of zinc fertilizer and short-term high temperature stress on wheat grain production and wheat flour proteins

TAO Zhi-qiang, WANG De-mei, CHANG Xu-hong, WANG Yan-jie, YANG Yu-shuang, ZHAO Guang-cai

2018, 17 (09): 1979-1990. DOI: 10.1016/S2095-3119(18)61911-2

Abstract （399） PDF in ScienceDirect

Content of wheat flour proteins affects the quality of wheat flour. Zinc nutrition in wheat can change the protein content of the flour. The inconsistency and instability of wheat grain quality during grain filling while under high temperature stress (HTS) are major problems in the production of high quality wheat. At present, there is a lack of studies on zinc fertilizer and HTS effects on wheat flour protein and the content of its components. For this study, treatment combinations of four levels of zinc fertilizers and exposure to a short-term HTS, at 20 d after flowering (D20), were tested on two wheat cultivars with different gluten levels. Individuals of a strong gluten wheat, Gaoyou 2018 (GY2018), and a medium gluten wheat, Zhongmai 8 (ZM8), were grown in pots at the Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing in 2015–2017. We measured grain yield and weight and the activities of two enzymes (nitrate reductase and glutamine synthetase) from the flag leaves, collected at D10 and D20. Total protein content, protein yield, and content of four protein components (albumin, gliadin, glutenin, and globulin) were measured from flour produced from the pot-grown plants. HTS significantly increased the contents of total protein, albumin, gliadin, and glutenin in wheat grains, and reduced the grain yield, grain weight, protein yield, globulin content, and flag leaf nitrate reductase (NR) and glutamine synthetase (GS) activities. The results showed that HTS and zinc fertilizer had greater impacts on the strong gluten cultivar compared to the medium gluten cultivar. Under HTS, grain yield decreased by 13 and 8% in GY2018 and ZM8, respectively; protein yield decreased by 7 and 8% in GY2018 and ZM8, respectively. Zinc fertilizer increased: grain and protein yields; grain weight; total protein, albumin, gliadin, and glutenin contents; protein yield; and NR and GS activities. In contrast, zinc fertilizer reduced the content of globulin. The addition of 15 mg Zn kg^–1 soil had the strongest effect on grain yield and quality as compared to the other three treatments (additions of 0, 30, and 45 mg Zn kg^–1 soil). Zinc fertilizer also reduced the negative effects of HTS on protein yield, content, and components’ content. Therefore, wheat grown with additional zinc in the soil can improve the quality of the flour.

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Physiological mechanisms of resistance to cold stress associated with 10 elite apple rootstocks

WANG Yan-xiu, HU Ya, CHEN Bai-hong, ZHU Yan-fang, Mohammed Mujitaba Dawuda, Sofkova Svetla

2018, 17 (04): 857-866. DOI: 10.1016/S2095-3119(17)61760-X

Abstract （588） PDF in ScienceDirect

A study was conducted in attempting to identify the cold-resistant apple rootstocks and to establish a comprehensive evaluation system. In this study, 10 elite apple dwarfing rootstocks (GM256, JM7, M26, M7, SC1, SH1, SH38, SH6, M9, and T337) were employed for the experiment and the following parameters were investigated under different low temperature stress conditions (0, –15, –20, –25, –30, and –35°C): the changes of the relative electrical conductivity (REC), anthocyanin content, protein content, soluble sugar content, soluble starch content, proline content, malondialdehyde (MDA) content, superoxide dismutase (SOD) activity, and peroxidase (POD) activity of the dormant branches. The inflection temperature that could represent the plant tissue semi-lethal temperature (LT₅₀) was obtained by the measurements of REC. The LT₅₀ was used to evaluate eight other indices. The results showed that there was no significant correlation between LT₅₀ and POD activity as well as between the soluble sugar, protein and proline contents at 0 and –15°C. Soluble starch content at 0 and –15°C and anthocyanin content at –15–(–30)°C were significantly but negatively correlated to the LT₅₀ and the MDA content at 0–(–20)°C was significantly positively correlated to the LT₅₀. Statistical analysis based on principal component analysis and LT₅₀ showed that cold resistant apple rootstocks in the decreasing order from high to low as GM256, SH6, SH38, SH1, SC1, M26, M7, JM7, T337, and M9.

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Gene engineering in swine for agriculture

WANG Yan-fang, HUANG Jiao-jiao, ZHAO Jian-guo

2017, 16 (12): 2792-2804. DOI: 10.1016/S2095-3119(17)61766-0

Abstract （822） PDF （451KB）（114）

Domestic pigs are the second most important source of meat world-wide, and the genetic improvement of economic traits, such as meat production, growth, and disease resistance, is a critical point for efficient production in pigs. Through conventional breeding and selection programs in pigs, which are painstakingly slow processes, some economic traits, such as growth and backfat, have been greatly improved over the past several decades. However, the improvement of many polygenetic traits is still very slow and challenging to be improved by conventional breeding strategies. The development of reproductive knowledge and a variety of techniques, including foreign gene transfer strategies, somatic cell nuclear transfer (SCNT) and particularly, recently developed nuclease-mediated genome editing tools, has provided efficient ways to produce genetically modified (GM) pigs for the dramatic improvement of economic traits. In this review, we briefly discuss the progress of genomic markers used in pig breeding program, trace the history of genetic engineering, mainly focusing on the progress of recently developed genome editing tools, and summarize the GM pigs which have been generated to aim at the agricultural purposes. We also discuss the specific challenges facing application of gene engineering in pig breeding, and future prospects.

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Characterization of salt tolerance and Fusarium wilt resistance of a sweetpotato mutant

ZHANG Huan, ZHANG Qian, WANG Yan-nan, LI Yan, ZHAI Hong, LIU Qing-chang, HE Shao-zhen

2017, 16 (09): 1946-1955. DOI: 10.1016/S2095-3119(16)61519-8

Abstract （720） PDF in ScienceDirect

The variant LM1 was previously obtained using embryogenic cell suspension cultures of sweetpotato variety Lizixiang by gamma-ray induced mutation, and then its characteristics were stably inherited through six clonal generations, thus this mutant was named LM1. In this study, systematic characterization of salt tolerance and Fusarium wilt resistance were performed between Lizixiang and mutant LM1. LM1 exhibited significantly higher salt tolerance compared to Lizixiang. The content of proline and activities of superoxide dismutase (SOD) and photosynthesis were significantly increased, while malonaldehyde (MDA) and H₂O₂contents were significantly decreased compared to that of Lizixiang under salt stress. The inoculation test with Fusarium wilt showed that its Fusarium wilt resistance was also improved. The lignin, total phenolic, jasmonic acid (JA) contents and SOD activity were significantly higher, while H₂O₂content was significantly lower in LM1 than that in Lizixiang. The expression level of salt stress-responsive and disease resistance-related genes was significantly higher in LM1 than that in Lizixiang under salt and Fusarium wilt stresses, respectively. This result provides a novel and valuable material for improving the salt tolerance and Fusarium wilt resistance of sweetpotato.

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Expression and functional analyses of the mitogen-activated protein kinase (MPK) cascade genes in response to phytohormones in wheat (Triticum aestivum L.)

YAO Su-fei, WANG Yan-xia, YANG Tong-ren, HAO Lin, LU Wen-jing, XIAO Kai

2017, 16 (01): 27-35. DOI: 10.1016/S2095-3119(16)61367-9

Abstract （1007） PDF in ScienceDirect

Mitogen-activated protein kinase (MPK) cascades consist of a set of kinase types (MPKKKs, MPKKs, MPKs) to establish
conserved signal-transducing modules mediating plant growth, development as well as responses to internal and external
cues. In this study, the expression patterns of six MPKKK, two MPKK, and 11 MPK genes in wheat in responses to external
treatments of phytohormones, including naphthylacetic acid (NAA), abscisic acid (ABA), 6-benzyladenine (6-BA), gibberellin
(GA^₃), salisylic acid (SA), jasmonic acid (JA), and ethylene (ETH), were investigated. Expression analysis revealed
that several of the MPK cascade genes are responses to the external phytohormone signaling. Of which, TaMPKKKA;3
is induced by 6-BA and NAA while TaMPK4 repressed by ETH, GA_3, SA, and JA; TaMPKKKA, TaMPKKKA;3 and TaMPK1
are down-regulated by ETH and GA^₃whereas TaMPK9 and TaMPK12 repressed by ETH and JA in addition that TaMPK12
also repressed by GA_3; TaMPK12;1 is down-regulated by ABA, GA₃ and SA while TaMPK17 repressed by all exogenous
phytonormones examined. TaMPK4, a MPK type gene previously characterized to mediate tolerance to phosphate (Pi)
deprivation, was functionally evaluated for its role in mediation of responses of plants to exogenous GA₃, ETH, SA, and JA.
Results indicated that overexpression and antisense expression of TaMPK4 in tobacco dramatically modify the growth of
seedlings upon treatments of GA₃, SA and JA, in which the overexpressors behaved deteriorated growth feature whereas
the seedlings with antisense expression of TaMPK4 exhibited improved seedling phenotype. The growth behaviors in
lines overexpressing or antisensely expressing TaMPK4 are closely associated with the biomass and the corresponding
hormone-associated parameters. These results demonstrated that TaMPK4 acts as a critical player in mediating the phytohormone
signaling. Our findings have identified the phytohormone-responsive MPK cascade genes in wheat and provided
a connection between the phytohormone-mediated responses and the MPK cascade pathways.

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A plastidic ATP/ADP transporter gene, IbAATP, increases starch and amylose contents and alters starch structure in transgenic sweetpotato

WANG Yan-nan, LI Yan, ZHANG Huan, ZHAI Hong, LIU Qing-chang, HE Shao-zhen

2016, 15 (9): 1968-1982. DOI: 10.1016/S2095-3119(15)61192-3

Abstract （1320） PDF in ScienceDirect

A plastidic adenosine triphosphate (ATP)/adenosine diphosphate (ADP) transporter (AATP) is responsible for importing ATP from the cytosol into plastids. In dicotyledonous plants, increasing ATP supply is a potential way to facilitate anabolic synthesis in heterotrophic plastids. In this study, a gene encoding the AATP protein, named IbAATP, was isolated from sweetpotato (Ipomoea batatas (L.) Lam.). Transcripts of IbAATP were predominantly detected in the storage roots and leaves and were induced by exogenous sucrose and subjected to circadian rhythm. Transient expression of IbAATP in tobacco and onion epidermal cells revealed the plastidic localization of IbAATP. The overexpression of IbAATP in sweetpotato significantly increased the starch and amylose contents and led to enlarged starch granules. The IbAATP-overexpressing plants showed altered fine structure of amylopectin, which contained an increased proportion of chains with a degree of polymerization (DP) of 10–23 and a reduced number of chains with a DP of 5–9 and 24–40. In addition, starch from the transgenic plants exhibited different pasting properties. The transcript levels of starch biosynthetic genes, including IbAGP, IbGBSSI, IbSSI-IV, and IbSBE, were differentially regulated in the transgenic plants. These results revealed the explicit role of IbAATP in the starch biosynthesis of sweetpotato and indicated that this gene has the potential to be used to improve starch content and quality in sweetpotato and other plants.

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Fast determination of multi-mycotoxins in corn by dispersive solid-phase extraction coupled with ultra-performance liquid chromatography with tandem quadrupole time-of-flight mass spectrometry

WANG Yan, DONG Yan-jie, LI Zeng-mei, DENG Li-gang, GUO Chang-ying, ZHANG Shu-qiu, LI Dapeng, ZHAO Shan-cang

2016, 15 (7): 1656-1666. DOI: 10.1016/S2095-3119(15)61287-4

Abstract （1836） PDF in ScienceDirect

A fast analytical method for the simultaneous determination of 9 mycotoxins, including aflatoxins (B₁, B₂, G₁, and G₂), fumonisins (B1, B2 and B3), zearalenone, and deoxynivalenol in corn using dispersive solid-phase extraction method and ultra-performance liquid chromatography coupled to tandem quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS) was developed and validated. Samples were extracted with acetonitrile-water (84:16, v:v, containing 1% acetic acid) using ultrasonic extraction. The extracts were purified with a dispersive SPE method using C18 as a cleaning agent. The final clear extracts were dried by nitrogen blowing and subsequently redissolved in methanol-water (5:5, v:v). The samples were then analyzed by UPLC-Q-TOF-MS with 0.1% formic acid in ammonium acetate-methanol as mobile phase. The mean recoveries were ranged from 68.0 to 120.0%, and the relative standard deviation (RSD) ranged from 0.18 to 6.29%. Limits of detections ranged from 0.05 to 50 μg kg⁻¹, and limits of quantification ranged from 0.1 to 200 μg kg⁻¹, which were below the legal limits set by the European Union for the legislated mycotoxins. The developed method was applied to 130 corn samples. Among the mycotoxins studied, aflatoxins B₁ and fumonisins B₁, B₂ and B₃ were the most predominant mycotoxins, and their concentrations were 0–593.12, 0–2.01×10⁴, 0–6.94×10³ and 0–3.05×10³ µg kg^–1, respectively.

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Analysis of the diversity and function of the alleles of the rice blast resistance genes Piz-t, Pita and Pik in 24 rice cultivars

WANG Yan, ZHAO Jia-ming, ZHANG Li-xia, WANG Ping, WANG Shi-wei, WANG Hui, WANG Xiao-xi, LIU Zhi-heng, ZHENG Wen-jing

2016, 15 (7): 1423-1431. DOI: 10.1016/S2095-3119(15)61207-2

Abstract （1271） PDF in ScienceDirect

Understanding the sequence diversity of rice blast resistance genes is important for breeding new resistant rice cultivars against the rice blast fungus Magnaporthe oryzae. In this study, we selected 24 rice cultivars with different genetic backgrounds to study the allelic diversity of rice blast resistance genes Piz-t, Pita and Pik. For Piz-t, a total of 17 allelic types were found within the 24 cultivars. Blast inoculations showed that most of the mutations can affect the function of the resistance gene. For Pita, except for the difference at the 918th amino acid, a majority of the 21 mutations were detected among the cultivars. Inoculations with blast isolates carrying Avr-Pita revealed that cultivars with mutations in other sites except for the 918th amino acid did not affect the function of the Pita gene. For Pik, a total of six allelic types were found within the 24 cultivars, but five of them lost the function of the resistance gene. In addition, we found that Piz-t, Pita and Pik were expressed constitutively in the 24 rice cultivars and the expression level was not related to resistance. Our results have provided the sequence diversity information of the resistance genes Piz-t, Pita and Pik among the popular rice cultivars grown in the northeast region of China.

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Isolation and molecular characterization of the FLOWERING LOCUS C gene promoter sequence in radish (Raphanus sativus L.)

XU Yuan-yuan, WANG Jing, NIE Shan-shan, HUANG Dan-qiong, WANG Yan, XU Liang, WANG Rong-hua, LUO Xiao-bo, LIU Li-wang

2016, 15 (4): 763-774. DOI: 10.1016/S2095-3119(15)61295-3

Abstract （1272） PDF in ScienceDirect

Both bolting and flowering times influence taproot and seed production in radish. FLOWERING LOCUS C (FLC) plays a key role in plant flowering by functioning as a repressor. Two genomic DNA sequences, a 3 046-bp from an early- and a 2 959-bp from a late-bolting radish line were isolated and named as RsFLC1 and RsFLC2, respectively, for they share approximately 87.03% sequence identity to the FLC cDNA sequences. The genomic DNA sequences, 1 466-bp and 1 744-bp, flanking the 5´-regions of RsFLC1 and RsFLC2, respectively, were characterized. Since both of them harbor the basic promoter elements, the TATA box and CAAT box, they were designated as PRsFLC1 and PRsFLC2. The transcription start site (TSS) was identified at 424 and 336 bp upstream of the start codon in PRsFLC1 and PRsFLC2, respectively. cis-regulatory elements including CGTCA (MeJA-responsive) and ABRE (abscisic acid-responsive) motifs were found in both promoters, while some cis-regulatory elements including TCA element and GARE-motif were present only in PRsFLC1. These sequence differences lead to the diversity of promoter core elements, which could partially result in the difference of bolting and flowering time in radish line NauDY13 (early-bolting) and Naulu127 (late-bolting). Furthermore, to investigate the activity of these promoters, a series of 5´-deletion fragment-GUS fusions were constructed and transformed into tobacco. GUS activity was detected in PRsFLC1-(1 to 4)-GUS-PS1aG-3 and PRsFLC2-(1 to 4)-GUS-PS1aG-3 transgenic tobacco leaf discs, and this activity progressively decreased from PRsFLC-1-GUS-PS1aG-3 to PRsFLC-5-GUS-PS1aG-3. Deletion analysis indicated that the cis-regulatory elements located at –395 bp to +1 bp may be critical for specifying RsFLC gene transcription.

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Selection and characterisation of lactic acid bacteria isolated from different origins for ensiling Robinia pseudoacacia and Morus alba L. leaves

NI Kui-kui, YANG Hui-xiao, HUA Wei, WANG Yan-ping, PANG Hui-li

2016, 15 (10): 2353-2362. DOI: 10.1016/S2095-3119(15)61251-5

Abstract （2160） PDF in ScienceDirect

The objective of this study was to isolate lactic acid bacteria (LAB) strains from different origins and to select the best strains for ensiling Robinia pseudoacacia (RB) and Morus alba L. (MB) leaves. The LAB strains were inoculated into the extracted liquid obtained from RB and MB leaves to evaluate the fermentation products. 11 LAB strains were selected for further experiments based on the highest products of lactic or acetic acid, including 1 strain of Weissella confusa, 2 of Lactobacillus reuteri and 8 of Lactobacillus plantarum. The API 50 CH fermentation experiment indicated that all of the selected 11 LAB strains utilised most of the carbohydrates. All the strains grew at temperatures between 10 and 45°C and at a pH of 3.5 to 4.5; however, L. reuteri F7 and F8 tolerated a pH as low as 3.0. All 11 LAB strains showed antibacterial activity against Listeria monocytogens, Escherichia coil, Salmonella sp. and Acetobacter pasteurianus; however, after excluding the effect of organic acids, only F7 and F8 still exhibited antibacterial activity. The present study indicated that the selected 11 LAB strains could be used to prepare silages of RB and MB leaves, especially L. reuteri F7 and F8.

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Genetic diversity of Ustilago hordei in Tibetan areas as revealed by RAPD and SSR

ZHOU Yu, CHAO Gui-mei, LIU Jia-jia, ZHU Ming-qi, WANG Yang, FENG Bai-li

2016, 15 (10): 2299-2308. DOI: 10.1016/S2095-3119(16)61413-2

Abstract （1550） PDF in ScienceDirect

Covered smut, which is caused by Ustilago hordei (Pers.) Lagerh., is one of the most damaging diseases of highland barley (Hordeum vulgare Linn. var. nudum Hook. f) in Tibetan areas of China. To understand the molecular diversity of U. hordei, a total of 27 isolates, which were collected from highland barley plants from Tibet, Sichuan, Qinghai, and Gansu provinces/autonomous region, were analyzed using random amplified polymorphic DNA (RAPD) and simple sequence repeat (SSR) markers. Among the 100 RAPD primers used, 24 primers exhibited polymorphism. A total of 111 fragments were amplified, of which 103 were polymorphic with a polymorphic rate of 92.79%. The average observed number of alleles (Na), effective number of alleles (Ne), Nei’s genetic diversity (H), Shannon’s information index (I) and polymorphism information content (PIC) value in the RAPD markers were 1.9279, 1.5016, 0.2974, 0.4503 and 0.6428, respectively. For the SSR markers, 40 of the 111 primer pairs exhibited polymorphism and provided a total of 119 bands, of which 109 were polymorphic and accounted for 91.60% of the total bands. The Na, Ne, H, I and PIC values of the SSR markers were 1.9160, 1.4639, 0.2757, 0.4211 and 0.4340, respectively. The similarity coefficients ranged from 0.4957 to 0.9261 with an average of 0.7028 among all the 27 isolates used. The dendrogram, which was developed based on the RAPD and SSR combined marker dataset showed that the 27 U. hordei isolates were divided into 3 clusters at similarity coefficient of 0.7314. We determined that RAPD and SSR markers can be successfully used to assess the genetic variation among U. hordei isolates. The RAPD markers revealed higher levels of genetic polymorphism than did the SSR markers in this study. There existed a moderate genetic difference among isolates. The molecular variation and differentiation was somewhat associated with geographical origin but not for all of the isolates.

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Development of a core set of SNP markers for the identification of upland cotton cultivars in China

KUANG Meng, WEI Shou-jun, WANG Yan-qin, ZHOU Da-yun, MA Lei, FANG Dan, YANG Wei-hua

2016, 15 (05): 954-962. DOI: 10.1016/S2095-3119(15)61226-6

Abstract （1960） PDF in ScienceDirect

Considering the advantages of single nucleotide polymorphisms (SNP) in genotyping and variety identification, the first set public SNP markers at Cotton Marker Database (http://www.cottonmarker.org/) were validated and screened across standard varieties of cotton distinctness, uniformity and stability (DUS) test, aiming to obtain an appropriate set of core SNP markers suitable for upland cotton cultivars in China. A total of 399 out of 1 005 SNPs from 270 loci including 170 insertions-deletions (InDels) were evaluated for their polymorphisms among 30 standard varieties using Sanger sequencing. As a result, 147 loci were sequenced successfully, 377 SNPs and 49 InDels markers were obtained. Among the 377 SNP markers, 333 markers (88.3%) were polymorphic between Gossypium hirsutum and G. barbadense, while 164 markers (43.5%) were polymorphic within upland cotton. As for InDel markers, the polymorphic rate is relatively lower than that of SNP both between species and within species. The homozygous DNA locus ratio of 121 SNPs was higher than 86.2% while that of other 43 SNPs was less than 70%. Only 64 SNPs displayed completely homozygous genotypes among all of the detected upland cotton varieties with 100% homozygous DNA locus ratio. At last, a set of 23 pairs of core SNPs were achieved in view of avoidance of linkage, with polymorphism information content (PIC) values varying from 0.21 to 0.38 with an average of 0.28. Genotype characteristics and genetic diversity were analyzed based on the set of core markers, while 40 pairs of core simple-sequence repeats (SSR) primers comprised of 10 sets of four multiplex PCR combinations were also used for analysis based on fluorescence detection system. Comparison results indicated that the genetic diversity level was almost equal, while various varieties were significantly different from each other. Genetic relationship revealed by SSR markers is related to geographic source to a certain extent. Meanwhile clustering results analyzed by SNP markers are more consistent with kinship, which demonstrated that the screen strategy for core SNP marker is effective.

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Effects of different nitrogen fertilizer management practices on wheat yields and N2O emissions from wheat fields in North China

LIU Ya-nan, LI Ying-chun, PENG Zheng-ping, WANG Yan-qun, MA Shao-yun, GUO Li-ping, LIN Er-da, HAN Xue

2015, 14 (6): 1184-1191. DOI: 10.1016/S2095-3119(14)60867-4

Abstract （2177） PDF in ScienceDirect

Nitrogen (N) is one of the macronutrients required for plant growth, and reasonable application of N fertilizers can increase crop yields and improve their quality. However, excessive application of N fertilizers will decrease N use efficiency and also lead to increases in N2O emissions from agricultural soils and many other environmental issues. Research on the effects of different N fertilizer management practices on wheat yields and N2O emissions will assist the selection of effective N management measures which enable achieving high wheat yields while reducing N2O emissions. To investigate the effects of different N management practices on wheat yields and soil N2O emissions, we conducted field trials with 5 treatments of no N fertilizer (CK), farmers common N rate (AN), optimal N rate (ON), 20% reduction in optimal rate+dicyandiamide (ON80%+DCD), 20% reduction in optimal rate+nano-carbon (ON80%+NC). The static closed chamber gas chromatography method was used to monitor N2O emissions during the wheat growing season. The results showed that there were obvious seasonal characteristics of N2O emissions under each treatment and N2O emissions were mainly concentrated in the sowing- greening stage, accounting for 54.6–68.2% of the overall emissions. Compared with AN, N2O emissions were decreased by 23.1, 45.4 and 33.7%, respectively, under ON, ON80%+DCD and ON80%+NC, and emission factors were declined by 22.2, 66.7 and 33.3%, respectively. Wheat yield was increased significantly under ON80%+DCD and ON80%+NC by 12.3 and 11.9%, respectively, relative to AN while there was no significant change in yield in the ON treatment. Compared with ON, overall N2O emissions were decreased by 29.1 and 13.9% while wheat yields improved by 18.3 and 17.9% under ON80%+DCD and ON80%+NC, respectively. We therefore recommend that ON80%+DCD and ON80%+NC be referred as effective N management practices increasing yields while mitigating emissions.

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Mycotoxin detection- Recent trends at global level

Jonathan Nimal Selvaraj, ZHOU Lu, WANG Yan, ZHAO Yue-ju, XING Fu-guo, DAI Xiao-feng, LIU Yang

2015, 14 (11): 2265-2281. DOI: 10.1016/S2095-3119(15)61120-0

Abstract （1765） PDF in ScienceDirect

Mycotoxin contamination in agro-food systems has been a serious concern globally during the last few decades. Mycotoxins are toxic secondary metabolites produced by fungi when they grow in agro-food products and feedstuff. Several detection techniques have been developed in recent years to detect mycotoxins in the food and feed effectively. HPLC based techniques are very common in usage in the laboratories for the testing of mycotoxins. In recent years, immuno-based assays is widely used and have been reported at large due to its sensitivity and limited detection time. Immuno assay-based kits were developed effectively to be used in the fields and in storage systems to detect the mycotoxin levels. Microarray-based immunoassays developed in the recent years could simultaneously detect aflatoxin, ochratoxin, and zearalenone with the higher sensitivity. Aptamer-based assays could target the detection of ochratoxin and aflatoxins and fumonisins at high specificity in food products. In recent years, several assays reported for the simultaneous multiple detection of different mycotoxin was based on HPLC and LC-MS/MS. There is a need for the use of these advanced technologies in the commercial scale.

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