Search Result

Select

Photosensitivity and a precise combination of size-dependent lambda-cyhalothrin microcapsules synergistically generate better insecticidal efficacy

GAO Yue, LUO Jian, SUN Yue, ZHANG Hua-wei, ZHANG Da-xia, LIU Feng, MU Wei, LI Bei-xing

2023, 22 (5): 1477-1488. DOI: 10.1016/j.jia.2022.08.081

Abstract （192） PDF in ScienceDirect

In this study, lambda-cyhalothrin (LC) loaded polyurea microcapsules (MCs) with different particle sizes were fabricated. All of the MCs showed varying degrees of physical collapse, which was more obvious among those with smaller particle sizes. MCs with particle sizes of 1.38 μm (MC-S), 5.13 μm (MC-M) and 10.05 μm (MC-L) had shell thicknesses of 39.6, 50.3 and 150.1 nm, respectively. MCs with smaller particles tended to have significantly faster release profiles, and the MC-S group had much higher bioactivity against Agrotis ipsilon and better foliar affinity on the peanut leaves (indicated by rainfastness) than MC-M and MC-L. All of the MCs exhibited light-enhanced release profiles and had much slower degradation compared with the emulsifiable concentrate (EC) group, among which MC-L had the slowest degradation. To generate MCs with both favorable quick efficacy and long-lasting efficacy, binary mixtures of MC-S, MC-M and MC-L were produced by mixing them in pairs at ratios of 2:1, 1:1 and 1:2. The mixture of MC-S:MC-L at 1:2 showed the best comprehensive efficacy in the peanut foliar spray scenario among the nine tested combinations, and its effective duration was three times longer than that of EC. Overall, the precise combination of MCs with different particle sizes can regulate the efficacy of pesticide control and serve as a strategy for the better utilization of pesticides.

Reference | Related Articles | Metrics

Select

Analysis of genetic diversity and population structure in sweetpotato using SSR markers

LIU Cheng, ZHAO Ning, JIANG Zhi-cheng, ZHANG Huan, ZHAI Hong, HE Shao-zhen, GAO Shao-pei, LIU Qing-chang

2023, 22 (11): 3408-3415. DOI: 10.1016/j.jia.2023.02.004

Abstract （196） PDF in ScienceDirect

Sweetpotato, Ipomoea batatas (L.) Lam., is an important food crop worldwide. Large scale evaluation of sweetpotato germplasm for genetic diversity is necessary to determine the genetic relationships between them and effectively use them in the genetic improvement. In this study, the genetic diversity of 617 sweetpotato accessions, including 376 landraces and 162 bred varieties from China and 79 introduced varieties from 11 other countries, was assessed using 30 simple sequence repeat (SSR) primer pairs with high polymorphism. Based on the population structure analysis, these sweetpotato accessions were divided into three groups, Group 1, Group 2 and Group 3, which included 228, 136 and 253 accessions, respectively. Consistent results were obtained by phylogenic analysis and principal coordinate analysis (PCoA). Of the three groups, Group 2 showed the highest level of genetic diversity and its accessions were mainly distributed in low-latitude regions. The accessions from South China exhibited the highest level of genetic diversity, which supports the hypothesis that Fujian and Guangdong were the first regions where sweetpotato was introduced to China. Analysis of molecular variance (AMOVA) indicated significant genetic differentiations between the different groups, but low levels of genetic differentiation existed between the different origins and accession types. These results provide valuable information for the better utilization of these accessions in sweetpotato breeding.

Reference | Related Articles | Metrics

Select

Long-term straw addition promotes moderately labile phosphorus formation, decreasing phosphorus downward migration and loss in greenhouse vegetable soil

ZHANG Yin-Jie, GAO Wei, LUAN Hao-an, TANG Ji-wei, LI Ruo-nan, LI Ming-Yue, ZHANG Huai-zhi, HUANG Shao-wen

2022, 21 (9): 2734-2749. DOI: 10.1016/j.jia.2022.07.028

Abstract （213） PDF in ScienceDirect

Phosphorus (P) leaching is a major problem in greenhouse vegetable production with excessive P fertilizer application. Substitution of inorganic P fertilizer with organic fertilizer is considered a potential strategy to reduce leaching, but the effect of organic material addition on soil P transformation and leaching loss remains unclear. The X-ray absorption near-edge structure (XANES) spectroscopy technique can determine P speciation at the molecular level. Here, we integrated XANES and chemical methods to explore P speciation and transformation in a 10-year field experiment with four treatments: 100% chemical fertilizer (4CN), 50% chemical N and 50% manure N (2CN+2MN), 50% chemical N and 50% straw N (2CN+2SN), and 50% chemical N and 25% manure N plus 25% straw N (2CN+2MSN). Compared with the 4CN treatment, the organic substitution treatments increased the content of labile P by 13.7–54.2% in the 0–40 cm soil layers, with newberyite and brushite being the main constituents of the labile P. Organic substitution treatments decreased the stable P content; hydroxyapatite was the main species and showed an increasing trend with increasing soil depth. Straw addition (2CN+2SN and 2CN+2MSN) resulted in a higher moderately labile P content and a lower labile P content in the subsoil (60–100 cm). Moreover, straw addition significantly reduced the concentrations and amounts of total P, dissolved inorganic P (DIP), and particulate P in leachate. DIP was the main form transferred by leaching and co-migrated with dissolved organic carbon. Partial least squares path modeling revealed that straw addition decreased P leaching by decreasing labile P and increasing moderately labile P in the subsoil. Overall, straw addition is beneficial for developing sustainable P management strategies due to increasing labile P in the upper soil layer for the utilization of plants, and decreasing P migration and leaching.

Reference | Related Articles | Metrics

Select

Study on burrowing nematode, Radopholus similis, pathogenicity test system in tobacco as host

YANG Si-hua, ZHAO Li-rong, DING Sha, TANG Shi-qiao, CHEN Chun, ZHANG Huan-xin, XU Chun-ling, XIE Hui

2022, 21 (9): 2652-2664. DOI: 10.1016/j.jia.2022.07.021

Abstract （152） PDF in ScienceDirect

Radopholus similis (Cobb 1893) Thorne (1949) is a destructive migratory endoparasitic plant nematode. In this study, the pathogenic process of R. similis infection in Nicotiana benthamiana (tobacco) was studied using quartz sand culture in laboratory. The results showed that R. similis mainly parasitised the root cortex, leading to cortical cell decomposition and tissue decay. We optimised the inoculation conditions to establish a method for determining the pathogenicity of R. similis as follows: (1) a glass culture tube was filled with quartz sand (about 1/3 of the height) and sterilised twice; (2) 20-day-old N. benthamiana seedlings were transplanted into test tubes and cultivated for 10 days at (25±1)°C; (3) R. similis female nematodes were inoculated in the root rhizosphere at a rate of 150 nematodes per plant; (4) the number of nematodes, disease severity, and growth of the plant at 30 days post-inoculation (dpi) were determined. The pathogenicity of eight R. similis populations from different hosts was determined, which proved the feasibility of this method.

Reference | Related Articles | Metrics

Select

A geranylgeranyl pyrophosphate synthase gene, IbGGPS, increases carotenoid contents in transgenic sweetpotato

LI Rui-jie, ZHAI Hong, HE Shao-zhen, ZHANG Huan, ZHAO Ning, LIU Qing-chang

2022, 21 (9): 2538-2546. DOI: 10.1016/j.jia.2022.07.029

Abstract （234） PDF in ScienceDirect

Geranylgeranyl pyrophosphate synthase (GGPS) plays an important role in the biosynthesis of carotenoids. In a previous study, the IbGGPS gene was isolated from a sweetpotato, Ipomoea batatas (L.) Lam., line Nongdafu 14 with high carotenoid contents, but its role and underlying mechanisms in carotenoid biosynthesis in sweetpotato were not investigated. In the present study, the IbGGPS gene was introduced into a sweetpotato cv. Lizixiang and the contents of β-carotene, β-cryptoxanthin, zeaxanthin and lutein were significantly increased in the storage roots of the IbGGPS-overexpressing sweetpotato plants. Further analysis showed that IbGGPS gene overexpression systematically up-regulated the genes involved in the glycolytic, 2-C-methyl-D-erythritol-4-phosphate (MEP) and carotenoid pathways, which increased the carotenoid contents in the transgenic plants. These results indicate that the IbGGPS gene has the potential for use in improving the carotenoid contents in sweetpotato and other plants.

Related Articles | Metrics

Select

Genome-wide association and linkage mapping strategies reveal genetic loci and candidate genes of phosphorus utilization in soybean

ZHANG Hua, WU Hai-yan, TIAN Rui, KONG You-bin, CHU Jia-hao, XING Xin-zhu, DU Hui, JIN Yuan, LI Xi-huan, ZHANG Cai-ying

2022, 21 (9): 2521-2537. DOI: 10.1016/j.jia.2022.07.005

Abstract （283） PDF in ScienceDirect

Insufficient available phosphorus in soil has become an important limiting factor for the improvement of yield and quality in soybean. The mining of QTLs and candidate genes controlling soybean phosphorus utilization related traits is a necessary strategy to solve this problem. In this study, 11 phosphorus utilization related traits of a natural population of 281 typical soybean germplasms and a recombinant inbred line (RIL) population of 270 lines were evaluated under different phosphorus conditions at two critical stages: the four-leaf stage as the seedling critical stage was designated as the T₁ stage, and the six-leaf stage as the flowering critical stage was designated as the T₂ stage. In total, 200 single nucleotide polymorphism (SNP) loci associated with phosphorus utilization related traits were identified in the natural population, including 91 detected at the T₁ stage, and 109 detected at the T₂ stage. Among these SNP loci, one SNP cluster (s715611375, ss715611377, ss715611379 and ss715611380) on Gm12 was shown to be significantly associated with plant height under the low phosphorus condition at the T₁ stage, and the elite haplotype showed significantly greater plant height than the others. Meanwhile, one pleiotropic SNP cluster (ss715606501, ss715606506 and ss715606543) on Gm10 was found to be significantly associated with the ratio of root/shoot, root and total dry weights under the low phosphorus condition at the T₂ stage, and the elite haplotype also presented significantly higher values for related characteristics under the phosphorus starvation condition. Furthermore, four co-associated SNP loci (ss715597964, ss715607012, ss715622173 and ss715602331) were identified under the low phosphorus condition at both the T₁ and T₂ stages, and 12 QTLs were found to be consistent with these genetic loci in the RIL population. More importantly, 14 candidate genes, including MYB transcription factor, purple acid phosphatase, sugar transporter and HSP20-like chaperones superfamily genes, etc., showed differential expression levels after low phosphorus treatment, and three of them were further verified by qRT-PCR. Thus, these genetic loci and candidate genes could be applied in marker-assisted selection or map-based gene cloning for the genetic improvement of soybean phosphorus utilization.

Reference | Related Articles | Metrics

Select

Effects of a decade of organic fertilizer substitution on vegetable yield and soil phosphorus pools, phosphatase activities, and the microbial community in a greenhouse vegetable production system

ZHANG Yin-Jie, GAO Wei, LUAN Hao-an, TAND Ji-wei, LI Ruo-nan, LI Ming-Yue, ZHANG Huai-zhi, HUANG Shao-wen

2022, 21 (7): 2119-2133. DOI: 10.1016/S2095-3119(21)63715-2

Abstract （224） PDF in ScienceDirect

Partial substitution of chemical fertilizers by organic amendments is adopted widely for promoting the availability of soil phosphorus (P) in agricultural production. However, few studies have comprehensively evaluated the effects of long-term organic substitution on soil P availability and microbial activity in greenhouse vegetable fields. A 10-year (2009–2019) field experiment was carried out to investigate the impacts of organic fertilizer substitution on soil P pools, phosphatase activities and the microbial community, and identify factors that regulate these soil P transformation characteristics. Four treatments included 100% chemical N fertilizer (4CN), 50% substitution of chemical N by manure (2CN+2MN), straw (2CN+2SN), and combined manure with straw (2CN+1MN+1SN). Compared with the 4CN treatment, organic substitution treatments increased celery and tomato yields by 6.9−13.8% and 8.6−18.1%, respectively, with the highest yields being in the 2CN+1MN+1SN treatment. After 10 years of fertilization, organic substitution treatments reduced total P and inorganic P accumulation, increased the concentrations of available P, organic P, and microbial biomass P, and promoted phosphatase activities (alkaline and acid phosphomonoesterase, phosphodiesterase, and phytase) and microbial growth in comparison with the 4CN treatment. Further, organic substitution treatments significantly increased soil C/P, and the partial least squares path model (PLS-PM) revealed that the soil C/P ratio directly and significantly affected phosphatase activities and the microbial biomass and positively influenced soil P pools and vegetable yield. Partial least squares (PLS) regression demonstrated that arbuscular mycorrhizal fungi positively affected phosphatase activities. Our results suggest that organic fertilizer substitution can promote soil P transformation and availability. Combining manure with straw was more effective than applying these materials separately for developing sustainable P management practices.

Reference | Related Articles | Metrics

Select

Transcriptome and phytochemical analyses reveal roles of characteristic metabolites in the taste formation of white tea during withering process

ZHOU Cheng-zhe, ZHU Chen, LI Xiao-zhen, CHEN Lan, XIE Si-yi, CHEN Guang-wu, ZHANG Huan, LAI Zhong-xiong, LIN Yu-ling, GUO Yu-qiong

2022, 21 (3): 862-877. DOI: 10.1016/S2095-3119(21)63785-1

Abstract （271） PDF in ScienceDirect

In the postharvest processing of tea leaves, withering is the first indispensable manufacturing process which produces the mellow, umami and sweet taste of white tea. In this study, we aimed to determine the dynamic changes of the main metabolites and clarify the key differentially expressed genes (DEGs) involved in forming the characteristic taste of white tea during withering. Phytochemical analyses revealed that the contents of total catechins and starch decreased continuously, whereas the contents of theaflavin, γ-aminobutyric acid (GABA), maltose, and soluble sugars increased significantly during withering (from 0–48 h). Meanwhile, the elevation of α-amylase (AMY), β-amylase (BAM), total amylase, and glutamate decarboxylase (GAD) activities may be correlated with the accumulation of GABA and maltose. By transcriptome sequencing, we detected 9 707, 15 921, 17 353, and 17 538 DEGs at 12, 24, 36, and 48 h of the withering process, respectively, compared with 0 h sample (fresh leaves). The transcript levels of most of the DEGs involved in catechin biosynthesis were significantly inhibited, whereas those involved in catechin oxidation were significantly up-regulated, which could be correlated to a decrease in catechin content and an increase in theaflavin content. The DEGs involved in GABA biosynthesis were considerably up-regulated, and the down-regulation of SPMS could reduce the competition for converting spermidine to GABA. The up-regulation of the AMY and BAM genes could trigger starch degradation, resulting in the increase of soluble sugar content. These results provide new insights into the importance of the withering process to the characteristic taste of white tea.

Reference | Related Articles | Metrics

Select

Molecular characterization of the ryanodine receptor from Adoxophyes orana and its response to lethal and sublethal doses of chlorantraniliprole

SUN Li-na, LIU Yan-di, ZHANG Huai-jiang, YAN Wen-tao, YUE Qiang, QIU Gui-sheng

2021, 20 (6): 1585-1595. DOI: 10.1016/S2095-3119(20)63356-1

Abstract （153） PDF in ScienceDirect

The insect ryanodine receptor (RyR) is a novel target of the anthranilic and phthalic insecticides, which have high activity against lepidopteran insects. Several diamide insecticides have been used to control pests in orchards in China. To enhance our understanding of the effects of diamides on RyRs, full-length cDNAs were isolated and characterized from the summer fruit tortrix moth, Adoxophyes orana, which is the most severe pest of stone and pome trees worldwide. In addition, the modulation of AoRyR mRNA expression by diamide insecticides was investigated. The AoRyR mRNA obtained had an open reading frame (ORF) of 15 402 bp nucleotides encoding 5 113 amino acids, and shared high and low identity with its orthologs in other insects and mammals of 77–92 and 45–47% identity, respectively. One alternative splice site with two exclusive exons was revealed in AoRyR (a/b). The usage of exon was more frequent in eggs and larvae than in pupae and adults. Quantitative real-time reverse transcription PCR (qRT-PCR) showed that AoRyR mRNA was expressed at all developmental stages, especially in eggs, male pupae and male adults. The expression levels of AoRyR mRNA in the whole body were up-regulated markedly after 3rd instar larvae were treated with chlorantraniliprole at LC₁₀, LC₂₀ and LC₅₀ dosages. The results could provide the basis for further functional studies of AoRyR and for the development of new chemicals with selective activity against insects.

Reference | Related Articles | Metrics

Select

Changes in organic C stability within soil aggregates under different fertilization patterns in a greenhouse vegetable field

LUAN Hao-an, YUAN Shuo, GAO Wei, TANG Ji-wei, LI Ruo-nan, ZHANG Huai-zhi, HUANG Shao-wen

2021, 20 (10): 2758-2771. DOI: 10.1016/S2095-3119(21)63646-8

Abstract （131） PDF in ScienceDirect

Knowledge of the stability of soil organic C (SOC) is vital for assessing SOC dynamics and cycling in agroecosystems. Studies have documented the regulatory effect of fertilization on SOC stability in bulk soils. However, how fertilization alters organic C stability at the aggregate scale in agroecosystems remains largely unclear. This study aimed to appraise the changes of organic C stability within soil aggregates after eight years of fertilization (chemical vs. organic fertilization) in a greenhouse vegetable field in Tianjin, China. Changes in the stability of organic C in soil aggregates were evaluated by four methods, i.e., the modified Walkley-Black method (chemical method), ¹³C NMR spectroscopy (spectroscopic method), extracellular enzyme assay (biological method), and thermogravimetric analysis (thermogravimetric method). The aggregates were isolated and separated by a wet-sieving method into four fractions: large macroaggregates
(>2 mm), small macroaggregates (0.25–2 mm), microaggregates (0.053–0.25 mm), and silt/clay fractions (<0.053 mm). The results showed that organic amendments increased the organic C content and reduced the chemical, spectroscopic, thermogravimetric, and biological stability of organic C within soil aggregates relative to chemical fertilization alone. Within soil aggregates, the content of organic C was the highest in microaggregates and decreased in the order microaggregates>macroaggregates>silt/clay fractions. Meanwhile, organic C spectroscopic, thermogravimetric, and biological stability were the highest in silt/clay fractions, followed by macroaggregates and microaggregates. Moreover, the modified Walkley-Black method was not suitable for interpreting organic C stability at the aggregate scale due to the weak correlation between organic C chemical properties and other stability characteristics within the soil aggregates. These findings provide scientific insights at the aggregate scale into the changes of organic C properties under fertilization in greenhouse vegetable fields in China.

Reference | Related Articles | Metrics

Select

Effects of different molecular weights of chitosan on methane production and bacterial community structure in vitro

TONG Jin-jin, ZHANG Hua, WANG Jia, LIU Yun, MAO Sheng-yong, XIONG Ben-hai, JIANG Lin-shu

2020, 19 (6): 1644-1655. DOI: 10.1016/S2095-3119(20)63174-4

Abstract （89） PDF in ScienceDirect

As a new feed additive, chitosan has been shown in recent years to have a certain role in reducing methane emissions from the gastrointestinal tracts of ruminants. However, the effects of chitosan with different molecular weights on rumen fermentation, methane production and bacterial community structure are not yet clear. A basal diet without chitosan served as the control (CTL), and the treatment diets were supplemented with chitosan with different molecular weights: 1 000 (1K), 3 000 (3K), 5 000 (5K), 50 000 (5W) and 200 000 (20W) dry matter (DM). Six fermentation units per treatment were established. Gas chromatography was used to measure the concentrations of methane, H₂ and volatile fatty acids (VFAs). The bacterial 16S rRNA genes were sequenced with an Illumina MiSeq platform and analysed to reveal the relative abundances of bacterial community taxa. The results showed that the propionate proportion was significantly increased by the addition of chitosan with different molecular weights (P<0.05), while methane production and the acetate proportion were significantly decreased (P<0.05). The relative abundances of Rikenellaceae_RC9_gut_group and Prevotellaceae_UCG_003 were significantly increased in the 3K chitosan group compared with the CTL group, whereas the relative abundance of Ruminococcaceae_NK4A214_group was significantly decreased (P<0.05). Correlation analyses of the relative abundances of the bacterial genera showed that Prevotella was positively related to propionate production (P<0.05). In conclusion, 3K chitosan could reduce methane production by replacing fibrolytic bacteria (Firmicutes and Fibrobacteres) with amylolytic bacteria (Bacteroidetes and Proteobacteria) in the bacterial community structure.

Reference | Related Articles | Metrics

Select

Aggregate-associated changes in nutrient properties, microbial community and functions in a greenhouse vegetable field based on an eight-year fertilization experiment of China

LUAN Hao-an, GAO Wei, TANG Ji-wei, LI Ruo-nan, LI Ming-yue, ZHANG Huai-zhi, CHEN Xin-ping, Dainius MASILIUNAS, HUANG Shao-wen

2020, 19 (10): 2530-2548. DOI: 10.1016/S2095-3119(20)63269-5

Abstract （149） PDF in ScienceDirect

Soil aggregation, microbial community, and functions (i.e., extracellular enzyme activities; EEAs) are critical factors affecting soil C dynamics and nutrient cycling. We assessed soil aggregate distribution, stability, nutrients, and microbial characteristics within >2, 0.25–2, 0.053–0.25, and <0.053 mm aggregates, based on an eight-year field experiment in a greenhouse vegetable field in China. The field experiment includes four treatments: 100% N fertilizer (CF), 50% substitution of N fertilizer with manure (M), straw (S), and manure plus straw (MS). The amounts of nutrient (N, P₂O₅, and K₂O) input were equal in each treatment. Results showed higher values of mean weight diameter in organic-amended soils (M, MS, and S, 2.43–2.97) vs. CF-amended soils (1.99). Relative to CF treatment, organic amendments had positive effects on nutrient (i.e., available N, P, and soil organic C (SOC)) conditions, microbial (e.g., bacterial and fungal) growth, and EEAs in the >0.053 mm aggregates, but not in the <0.053 mm aggregates. The 0.25–0.053 mm aggregates exhibited better nutrient conditions and hydrolytic activity, while the <0.053 mm aggregates had poor nutrient conditions and higher oxidative activity among aggregates, per SOC, available N, available P, and a series of enzyme activities. These results indicated that the 0.25–0.053 mm (<0.053 mm) aggregates provide suitable microhabitats for hydrolytic (oxidative) activity. Interestingly, we found that hydrolytic and oxidative activities were mainly impacted by fertilization (58.5%, P<0.01) and aggregate fractions (50.5%, P<0.01), respectively. The hydrolytic and oxidative activities were significantly (P<0.01) associated with nutrients (SOC and available N) and pH, electrical conductivity, respectively. Furthermore, SOC, available N, and available P closely (P<0.05) affected microbial communities within >0.25, 0.25–0.053, and <0.053 mm aggregates, respectively. These findings provide several insights into microbial characteristics within aggregates under different fertilization modes in the greenhouse vegetable production system in China.

Reference | Related Articles | Metrics

Select

Genomic and transcriptomic insights into cytochrome P450 monooxygenase genes involved in nicosulfuron tolerance in maize (Zea mays L.)

LIU Xiao-min, XU Xian, LI Bing-hua, YAO Xiao-xia, ZHANG Huan-huan, WANG Gui-qi, HAN Yu-jun

2018, 17 (08): 1790-1799. DOI: 10.1016/S2095-3119(18)61921-5

Abstract （375） PDF in ScienceDirect

Postemergence application of nicosulfuron for weed control in maize fields can cause great damage to certain maize inbred lines and hybrids. Two maize genotypes, tolerant inbred (HBR) and sensitive inbred (HBS), were found to significantly differ in their phenotypic responses to nicosulfuron, with the EC₅₀ (50% effective concentration) values differed statistically (763.6 and 5.9 g a.i. ha^–1, respectively). Pre-treatment with malathion, a known cytochrome P450 inhibitor, increased nicosulfuron injury in both HBR and HBS. Our results support the hypothesis that nicosulfuron selectivity in maize is associated with cytochrome P450 metabolism. Further analysis of the maize genome resulted in the identification of 314 full length cytochrome P450 monooxygenase (CYP) genes. These genes were classified into 2 types, 10 clans and 44 families. The CYP71 clan was represented by all A-type genes (168) belonging to 17 families. Nine clans possessed 27 families containing 146 non-A-type genes. The consensus sequences of the heme-binding regions of A-type and non-A-type CYP proteins are ‘PFGXGRRXCPG’ and ‘FXXGPRXCXG’, respectively. Illumina transcriptome sequence results showed that there were 53 differentially expressed CYP genes on the basis of high variation in expression between HBS and HBR, nicosulfuron-treated and untreated samples. These genes may contribute to nicosulfuron tolerance in maize. A hierarchical clustering analysis obtained four main clusters named C1 to C4 in which 4, 15, 21, and 13 CYP genes were found in each respective cluster. The expression patterns of some CYP genes were confirmed by RT-qPCR analysis. The research will improve our understanding of the function of maize cytochrome P450 in herbicide metabolism.

Reference | Related Articles | Metrics

Select

Molecular mapping of YrTZ2, a stripe rust resistance gene in wild emmer accession TZ-2 and its comparative analyses with Aegilops tauschii

WANG Zhen-zhong, XIE Jing-zhong, GUO Li, ZHANG De-yun, LI Gen-qiao, FANG Ti-lin, CHEN Yongxing, LI Jun, WU Qiu-hong, LU Ping, LI Miao-miao, WU Hai-bin, ZHANG Huai-zhi, ZHANG Yan, YANG Wu-yun, LUO Ming

2018, 17 (06): 1267-1275. DOI: 10.1016/S2095-3119(17)61846-X

Abstract （475） PDF in ScienceDirect

Wheat stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), is a devastating disease that can cause severe yield losses. Identification and utilization of stripe rust resistance genes are essential for effective breeding against the disease. Wild emmer accession TZ-2, originally collected from Mount Hermon, Israel, confers near-immunity resistance against several prevailing Pst races in China. A set of 200 F_6:7 recombinant inbred lines (RILs) derived from a cross between susceptible durum wheat cultivar Langdon and TZ-2 was used for stripe rust evaluation. Genetic analysis indicated that the stripe rust resistance of TZ-2 to Pst race CYR34 was controlled by a single dominant gene, temporarily designated YrTZ2. Through bulked segregant analysis (BSA) with SSR markers, YrTZ2 was located on chromosome arm 1BS flanked by Xwmc230 and Xgwm413 with genetic distance of 0.8 cM (distal) and 0.3 cM (proximal), respectively. By applying wheat 90K iSelect SNP genotyping assay, 11 polymorphic loci (consisting of 250 SNP markers) closely linked to YrTZ2 were identified. YrTZ2 was further delimited into a 0.8-cM genetic interval between SNP marker IWB19368 and SSR marker Xgwm413, and co-segregated with SNP marker IWB28744 (co-segregated with 28 SNP). Comparative genomics analyses revealed high level of collinearity between the YrTZ2 genomic region and the orthologous region of Aegilops tauschii 1DS. The genomic region between loci IWB19368 and IWB31649 harboring YrTZ2 is orthologous to a 24.5-Mb genomic region between AT1D0112 and AT1D0150, spanning 15 contigs on chromosome 1DS. The genetic and comparative maps of YrTZ2 provide a framework for map-based cloning and marker-assisted selection of YrTZ2.

Reference | Related Articles | Metrics

Select

Phenolic and flavonoid contents of mandarin (Citrus reticulata Blanco) fruit tissues and their antioxidant capacity as evaluated by DPPH and ABTS methods

ZHANG Hua, YANG Yi-fei, ZHOU Zhi-qin

2018, 17 (01): 256-263. DOI: 10.1016/S2095-3119(17)61664-2

Abstract （724） PDF in ScienceDirect

The total phenolic and flavonoid contents in the fruit tissues (peels, pulp residues, seeds, and juices) of 19 citrus genotypes belonged to Citrus reticulata Blanco were evaluated and their antioxidant capacity was tested by 2,2-diphenyl-1-picrylhydrazyl radicals (DPPH) method and 2,2´-azino-bis(3-ethylbenzthiozoline-6)-sulphonic acid (ABTS) method. The total phenolic and flavonoid contents, and their antioxidant capacity varied in different citrus fruit tissues. Generally, the peel had both the highest average of total phenolics (27.18 mg gallic acid equivalent (GAE) g^–1 DW) and total flavonoids (38.97 mg rutin equivalent (RE) g^–1 DW). The highest antioxidant capacity was also the average of DPPH value (21.92 mg vitamin C equivalent antioxidant capacity (VCEAC) g^–1 DW) and average of ABTS value (78.70 mg VCEAC g^–1 DW) in peel. The correlation coefficient between the total phenolics and their antioxidant capacity of different citrus fruits tissues ranged from 0.079 to 0.792, and from –0.150 to 0.664 for the total flavonoids. The antioxidant capacity of fruit tissues were correlated with the total phenoilc content and flavonoid content except in case of the peel. In addition, the total phenolic content and antioxidant capacity varied in different citrus genotypes. Manju and Karamandarin were better genotypes with higher antioxidation and the phenolic content, however Shagan was the poorest genotype with lower antioxidation and the phenolic content.

Reference | Related Articles | Metrics

Select

Genetic variation of yellow pigment and its components in foxtail millet (Setaria italica (L.) P. Beauv.) from different eco-regions in China

YANG Yan-bing, JIA Guan-qing, DENG Li-gang, QIN Ling, CHEN Er-ying, CONG Xin-jun, ZOU Renfeng, WANG Hai-lian, ZHANG Hua-wen, LIU Bin, GUAN Yan-an, DIAO Xian-min, YIN Yan-ping

2017, 16 (11): 2459-2469. DOI: 10.1016/S2095-3119(16)61598-8

Abstract （834） PDF in ScienceDirect

Kernel color is an important trait for assessing the commercial and nutritional quality of foxtail millet. Yellow pigment content (YPC) and carotenoid components (lutein and zeaxanthin) of 270 foxtail millet accessions, including 50 landraces and 220 improved cultivars, from four different eco-regions in China were surveyed using spectrophotometry and high performance liquid chromatography methods. Results indicated that YPC had rich variance, ranging from 1.91 to 28.54 mg kg^–1, with an average value of 17.80 mg kg^–1. The average YPC of improved cultivars (18.31 mg kg^–1) was significantly higher than that of landraces (15.51 mg kg^–1). The YPC in cultivars from the Loess Plateau spring sowing region (LPSSR) was the highest (20.59 mg kg^–1), followed by the North China summer sowing region (NCSSR, 18.25 mg kg^–1), the northeast spring sowing region (NSSR, 17.25 mg kg^–1), and the Inner Mongolia Plateau spring sowing region (IMPSSR, 13.92 mg kg^–1). The variation coefficients of YPC in cultivars from NSSR, LPSSR, and IMPSSR were higher than that from NCSSR. A similar carotenoid profile was also obtained for 270 foxtail millet cultivars. Lutein and zeaxanthin accounted for approximately 55–65% of YPC in accessions. The lutein content was higher than zeaxanthin content in all cultivars. The ratio of lutein to zeaxanthin ranged from 1.51 to 6.06 with an average of 3.34. YPC was positively correlated with lutein (r=0.935, P<0.01), zeaxanthin (r=0.808, P<0.01), and growth duration (r=0.488, P<0.01), whereas it was negatively correlated with grain protein (r=−0.332, P<0.01) and 1 000-kernel weight (r=−0.153, P<0.05). Our study is useful for screening and selecting cultivars with high levels of yellow pigment and for enhancing phytochemical concentrations in breeding programs.

Reference | Related Articles | Metrics

Select

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.

Reference | Related Articles | Metrics

Select

Fine mapping of powdery mildew resistance gene PmTm4 in wheat using comparative genomics

XIE Jing-zhong, WANG Li-li, WANG Yong, ZHANG Huai-zhi, ZHOU Sheng-hui, WU Qiu-hong, CHEN Yong-xing, WANG Zhen-zhong, WANG Guo-xin, ZHANG De-yun, ZHANG Yan, HU Tie-zhu, LIU Zhi-yong

2017, 16 (03): 540-550. DOI: 10.1016/S2095-3119(16)61377-1

Abstract （1388） PDF in ScienceDirect

Powdery mildew, caused by Blumeria graminis f. sp. tritici, is one of the most severe wheat diseases. Mining powdery mildew resistance genes in wheat cultivars and their appliance in breeding program is a promising way to control this disease. Genetic analysis revealed that a single dominant resistance gene named PmTm4 originated from Chinese wheat line Tangmai 4 confers resistance to prevailing isolates of B. graminis f. sp. tritici isolate E09. Detailed comparative genomics analyses helped to develop closely linked markers to PmTm4 and a fine genetic map was constructed using large F₂ population, in which PmTm4 was located into a 0.66-cM genetic interval. The orthologous subgenome region of PmTm4 in Aegilops tauschii was identified, and two resistance gene analogs (RGA) were characterized from the corresponding sequence scaffolds of Ae. tauschii draft assembly. The closely linked markers and identified Ae. tauschii orthologs in the mapping interval provide an entry point for chromosome landing and map-based cloning of PmTm4.

Reference | Related Articles | Metrics

Select

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.

Reference | Related Articles | Metrics

Select

Empirical study on optimal reinsurance for crop insurance in China from an insurer’s perspective

ZHOU Xian-hua, WANG Yun-bo, ZHANG Hua-dong, WANG Ke

2015, 14 (10): 2121-2133. DOI: 10.1016/S2095-3119(14)60998-9

Abstract （1360） PDF in ScienceDirect

This study investigates the optimal reinsurance for crop insurance in China in an insurer’s perspective using the data from Inner Mongolia, Jilin, and Liaoning, China. On the basis of the loss ratio distributions modeled by AnHua Crop Risk Evaluation System, we use the empirical model developed by Tan and Weng (2014) to study the optimal reinsurance design for crop insurance in China. We find that, when the primary insurer’s loss function, the principle of the reinsurance premium calculation, and the risk measure are given, the level of risk tolerance of the primary insurer, the safety loading coefficient of the reinsurer, and the constraint on reinsurance premium budget affect the optimal reinsurance design. When a strict constraint on reinsurance premium budget is implemented, which often occurs in reality, the limited stop loss reinsurance is optimal, consistent with the common practice in reality. This study provides suggestions for decision making regarding the crop reinsurance in China. It also provides empirical evidence for the literature on optimal reinsurance from the insurance market of China. This evidence undoubtedly has an important practical significance for the development of China’s crop insurance.

Reference | Related Articles | Metrics

Select

Nitrogen Nutrition Index and Its Relationship with N Use Efficiency, Tuber Yield, Radiation Use Efficiency, and Leaf Parameters in Potatoes

HU Da-wei, SUN Zhou-ping, LI Tian-lai, YAN Hong-zhi , ZHANG Hua

2014, 13 (5): 1008-1016. DOI: 10.1016/S2095-3119(13)60408-6

Abstract （2034） PDF in ScienceDirect

Knowledge about crop growth processes in relation to N limitation is necessary to optimize N management in farming system. Plant-based diagnostic method, for instance nitrogen nutrition index (NNI) were used to determine the crop nitrogen status. This study determines the relationship of NNI with agronomic nitrogen use efficiency (AEN), tuber yield, radiation use efficiency (RUE) and leaf parameters including leaf area index (LAI), areal leaf N content (NAL) and leaf N concentration (NL). Potatoes were grown in field at three N levels: no N (N1), 150 kg N ha-1 (N2), 300 kg N ha-1 (N3). N deficiency was quantified by NNI and RUE was generally calculated by estimating of the light absorbance on leaf area. NNI was used to evaluate the N effect on tuber yield, RUE, LAI, NAL, and NL. The results showed that NNI was negatively correlated with AEN, N deficiencies (NNI<1) which occurred for N1 and N2 significantly reduced LAI, NL and tuber yield; whereas the N deficiencies had a relative small effect on NAL and RUE. To remove any effect other than N on these parameters, the actual ratio to maximum values were calculated for each developmental stage of potatoes. When the NNI ranged from 0.4 to 1, positive linear relationships were obtained between NNI and tuber yield, LAI, NL, while a nonlinear regression fitted the response of RUE to NNI.

Reference | Related Articles | Metrics

About JIA

Editorial board

For authors