Institutional Repository of Chengdu Institute of Biology, CAS
Not a member yet
6513 research outputs found
Sort by
基于660K芯片小麦高密度遗传连锁图谱及其应用
No full text高密度遗传连锁图谱对小麦基因定位克隆、分子育种及基因组学研究至关重要。多种分子标记被成功应用于小麦遗传图谱的构建,基于不同作图群体已释放40余个版本小麦遗传图谱,以高密度遗传图谱为桥梁,实现上述遗传图谱的整合将为分子育种奠定重要的遗传资源。本研究利用小麦科农9204×京411构建的重组自交系KJ-RIL群体及660K小麦基因组芯片(Affymetrix Wheat660 chip),绘制了包含119566个位点的小麦高密度遗传连锁图谱,图谱总长度4424.4cM,标记间平均距离为0.04cM/位点。经比较分析,该高密度遗传图谱与90K、820K高密度整合图谱及小麦基因组物理图谱均具有较好的共线性对应关系。结合前人已报道遗传图谱及其标记序列信息,以660K芯片高密度遗传连锁图谱为骨架,梳理AFLP、RFLP、RAPD、SSR、EST-SSR、STS、SRAP、DarT、SNP等标记遗传位置及基因组序列信息,构建了小麦高密度一致性整合图谱。结合表型数据、高密度遗传图谱极其基因型值,对控制穗粒数主效QTL-qKnps-4A、株高主效QTL-qPh-6B等多个QTL进行了精准定位,绘制了靶区段高密度遗传连锁图谱,该结果为靶基因的精细定位及图位克隆奠定基础
Organocatalytic asymmetric Michael addition of pyrazoleamides to beta-phthalimidonitroethene
No full textA highly organocatalyzed asymmetric Michael addition reaction of pyrazoleamides to beta-phthalimidonitroethene has been developed with a chiral bifunctional thiourea-tertiary amine as the catalyst. A wide range of gamma-nitro beta-amino amides were readily obtained in good to excellent yields with high diastereo-and enantioselectivities (up to 99% yield, 99% ee and >20:1 dr). The large scale experiment and transformation of the product have also been demonstrated. (C) 2017 Elsevier Ltd. All rights reserved
唐家河国家级自然保护区鸟类群落结构与多样性
No full text了解鸟类资源状况、群落结构和空间分布特征是后续开展长期鸟类监测的工作基础.通过样线和网捕环志调查并综合之前的访问调查记录,在唐家河国家级自然保护区共发现鸟类313种,分属于16目57科.从居留型看,留鸟182种,候鸟109种(其中夏候鸟90种、冬候鸟19种),旅鸟及迷鸟22种.国家一级保护鸟类6种,二级保护鸟类42种.鸟类分布型共有13种,以东洋型(76种鸟)和喜马拉雅—横断山区型(68种鸟)为主.各类生境中的鸟类多样性由高到低依次为常绿阔叶林,常绿与落叶阔叶混交林,针阔混交林,农田,亚高山针叶林,高山灌丛与高山草甸.总体上,唐家河保护区鸟类特有种和受保护物种较多,群落结构与生境关系密切,生物多样性随着海拔的上升而缓慢下降
Flexible shift on gene body methylation and transcription of LpCYP72A161 exposed to temperature stress in perennial ryegrass
No full textEpigenetic modifications of plants, such as DNA methylation, are often regulated by environmental stress. P450 monooxygenases play an important role in plant growth and development, and often respond to environmental stimuli. However, little is known about the mechanism that regulates P450 gene expression changes upon abiotic stress. Here, we tested the hypothesis that P450 s responds to temperature stress through changes in gene body methylation. A P450 gene that was up-regulated under heat and cold treatments was cloned from perennial ryegrass, and named LpCYP72A161 according to the amino acid sequence homology. LpCYP72A161, which contained four exons and three introns, showed CG methylation, and the methylated sites were mainly located on CpG islands within exon 1 and 4. Temperature stress resulted in a significant reduction in methylation of CG sites on exon 1 but not other CG islands. We observed that overlapping mCGs sites were demethylated upon heat and cold treatment; however, heat-treatment caused a higher demethylation and higher expression of LpCYP72A161 compared with cold treatment. In addition, plants that were recovered from heat treatment showed partial recovery of methylation and expression. In conclusion, LpCYP72A161, a CG-methylated gene, exhibited a flexible shift of gene body methylation in exon 1 under heat and cold stress, and the methylation level was negatively correlated to transcript abundance. By analyzing the changes in methylation patterns of the P450 gene LpCYP72A161 during early response to temperature stress in perennial ryegrass, our research provides a new understanding of the regulation of the gene body methylation in temperature stress
Genetic variation and phylogeographic structure of the cotton aphid, Aphis gossypii, based on mitochondrial DNA and microsatellite markers
No full textAphis gossypii, one of the most important agricultural pests in the world, can cause serious economic losses in the main crop-producing areas. To clarify issues such as the genetic differentiation, genetic structure, and demographic history of A. gossypii populations, we used 10 nuclear microsatellite loci (SSR) and two mitochondrial gene sequences (COI and Cytb) to investigate genetic diversity and population structure of A. gossypii populations that were collected from 33 sampling sites in China from different climatic zones. SSR and mtDNA data suggested low to moderate levels of genetic diversity. A star-shaped network of mtDNA haplotypes indicated that the maternal ancestor of China cotton aphids likely originated in Xinjiang. The POPTREE, STRUCTURE and principal coordinate analysis (PCoA) revealed two genetic clusters: an eastern and a western region group. Isolation by distance (IBD) results showed a positive correlation between geographic distance and genetic distance in the vast eastern region but not in the western region. Neutrality testing and mismatch distribution analysis provided strong evidence for a recent rapid expansion in most populations. Genetic bottleneck was not detected in A. gossypii populations of China. The present work can help us to develop strategies for managing this pest
α-淀粉酶对小麦糊化特性的影响
No full text淀粉糊化特性是反映淀粉品质的重要指标,与谷物的营养及加工性能有很强的相关性,而谷物中α-淀粉酶活性是影响淀粉糊化特性的重要因素,为了解我国正常成熟小麦的糊化特性受α-淀粉酶活性的影响,筛选了30份α-淀粉酶活性差异较大的小麦材料,进行降落值、总α-淀粉酶活性测定、α-淀粉酶蛋白电泳分离及糊化特性差异分析.结果显示:供试材料的降落值和总α-淀粉酶活性(OD值)差异很大,分别为62-524 s和0.12-2.87.根据降落值和总α-淀粉酶活性可将供试材料分为3类,I、Ⅱ、Ⅲ类的降落值分别为122.40(±20.25)s、373.67(±13.81)s、452.00(±3.39)s;总α-淀粉酶活性(OD值)分别为2.35(±0.21)、0.74(±0.06)、0.22(±0.00),这3类材料的总α-淀粉酶活性呈现显著差异且具有浓度差异明显的α-淀粉酶电泳条带;供试材料的糊化特性差异主要受基因型差异控制,受环境影响较小;迟熟α-淀粉酶显著降低小麦粉的峰值粘度、低谷粘度、最终粘度等多项糊化参数,并扩大材料间糊化特性差异.相关性分析表明,小麦籽粒α-淀粉酶活性与降落值极显著负相关(r=-0.97,P<0.01),降落值和峰值粘度差值都能较好地预测材料间α-淀粉酶活性的差异.本研究表明α-淀粉酶活性对淀粉糊化特性有显著降低的影响,在选择小麦育种或加工材料时应对材料的α-淀粉酶活性进行评估
Long-term cultivation of Bt rice expressing the Cry1Ab/1Ac gene reduced phytoparasitic nematode abundance but did not affect other nematode parameters in paddy fields
No full textThe uncertainty of ecological risks and the effects of growing transgenic Bt rice on the environment hamper its commercial production. Here, soil nematode communities were used as an indicator of soil health and soil food web structure to evaluate the potential effects of growing Bt rice without chemical insecticides for 3 years in the paddy field. The nematodes and soil physicochemical properties of Bt rice fields were compared to the near-isogenic control, non-Bt rice fields. A total of 108,363 specimens belonging to 28 different genera were enumerated. The Hirschmanniella, Tobrilus, Dorylaimus and Filenchus were dominant genera. A three-year paddy rice cultivation of Bt rice (Huahui 1) negatively affected the abundance of phytoparasitic nematodes but did not affect the total number of nematodes, the abundance and relative abundance of free-living nematodes, genera richness, diversity indices, soil food web conditions, or community compositions. However, apparent seasonal and inter-annual changes in these variables were observed, indicating that the impact of environmental factors was more stronger than that of the Bt toxin. In conclusion, the potential ecological risks of Bt rice on soil health and sustainability warrant further research to disentangle the impacts from various confounding environmental factors. (C) 2017 Elsevier B.V. All rights reserved