水稻新品种测试的标准品种DNA指纹图谱多样性分析

以植物新品种特异性、一致性和稳定性(DUS)测试指南中选定的49个水稻标准品种为材料,采用农业行业标准(NY/1433-2077)中推荐的24对水稻SSR引物进行DNA指纹图谱构建和遗传多样性分析。结果表明,24对SSR引物在19个籼稻和30个粳稻品种中分别检测到141和156个等位变异,平均每对引物可以检测到5.88(籼稻)和6.50(粳稻)个等位变异;籼、粳稻类群中24对SSR引物的平均Shannon's多样性指数分别为1.5141(1.0460~1.9959)和1.4389(0.4677~2.4503);经聚类分析后,籼、粳稻群体内品种间的相似系数分别介于0.45~0.81和0.36~0.76,取相似系数0.72为阈值,可将19个籼稻和30个粳稻品种分别分为16类和28类。由此可见,本研究的49个品种的遗传多样性丰富。结合形态性状和基因型聚类分析结果,可将现有的49个水稻DUS测试标准品种减少到46个。     

Crystal structures of E. coli CcmG and its mutants reveal key roles of the N-terminal beta-sheet and the fingerprint region

CcmG, also designated DsbE, functions as a periplasmic protein thiol:disulfide oxidoreductase and is required for cytochrome c maturation. Here we report the crystal structures of Escherichia coli CcmG and its two mutants, P144A and the N-terminal fifty seven-residue deletion mutant, and two additional deletion mutants were studied by circular dichroism. Structural comparison of E. coli CcmG with its deletion mutants reveals that the N-terminal beta-sheet is essential for maintaining the folding topology and consequently maintaining the active-site structure of CcmG. Pro144 and Glu145 are key residues of the fingerprint region of CcmG. Pro144 is in cis-configuration, and it makes van der Waals interactions with the active-site disulfide Cys80-Cys83 and forms a C--H...O hydrogen bond with Thr82, helping stabilize the active-site structure. Glu145 forms a salt-bridge and hydrogen-bond network with other residues of the fingerprint region and with Arg158, further stabilizing the active-site structure. The cis-configuration of Pro144 makes the backbone nitrogen and oxygen of Ala143 exposed to solvent, favorable for interacting with binding partners. The key role of cis-Pro144 is verified by the P144A mutant, which contains trans-Ala144 and displays redox property changes. Structural comparison of E. coli CcmG with the recently reported structure of CcmG in complex with the N-terminal domain of DsbD reveals that Tyr141 undergoes conformational changes upon binding DsbD. A cis-proline located at the N-terminus of the first beta-strand of the betabetaalpha motif of the thioredoxin-like domain is a conserved structural feature of the thioredoxin superfamily.     

Genetic Diversity of Magnaporthe grisea in China as Revealed by DNA Fingerprint Haplotypes and Pathotypes

We determined DNA fingerprint haplotypes and pathotypes of the rice‐blast fungus Magnaporthe grisea collected from 13 areas in China. This DNA fingerprinting analysis, using rep‐PCR, of 381 haplotypes (482 isolates) from China indicated that the M. grisea populations cannot be delineated into region‐specific groups. Analyses of the number of alleles (na), Nei's gene diversity, unbiased genetic distance, and Shannon's Information index among 13 populations showed that clusters were not related to the geographic distance between populations with the exception of the Ningxia (NX) and Jilin (JL) cluster. Among northern populations, NX and JL were more similar to one another than to other populations. Pathogen populations consisting of 121 isolates from China were grouped into 53 pathotypes on the basis of disease reaction in differential rice lines. Isolates assayed for pathotypes were detected based on disease reactions. No correlation was observed between fingerprint groups and pathotypes of the pathogen. High frequency of virulence was found on the rice line Shin2 (Pi‐k^s and Pi‐sh) followed by PiNo.4 (Pi‐ta² and Pi‐sh) and K1 (Pi‐ta), while it was low on Kanto 51 (Pi‐k + ?), K3 (Pi‐k^h), and Fujisaka (Pi‐i and Pi‐sh). Virulence was rare on Toride 1 (Pi‐z^t and Pi‐sh). Tetep (Pi‐k^h + ?) was predicted to be a highly effective, as none of the isolates infected this line. These blast‐resistant rice lines can be used in resistance breeding for the effective management of rice blast in the respective regions of China.     

An AFLP clock for the absolute dating of shallow-time evolutionary history based on the intraspecific divergence of southwestern European alpine plant species

The dating of recent events in the history of organisms needs divergence rates based on molecular fingerprint markers. Here, we used amplified fragment length polymorphisms (AFLPs) of three distantly related alpine plant species co-occurring in the Spanish Sierra Nevada, the Pyrenees and the southwestern Alps/Massif Central to establish divergence rates. Within each of these species ( Gentiana alpina , Kernera saxatilis and Silene rupestris ), we found that the degree of AFLP divergence ( D _N72) between mountain phylogroups was significantly correlated with their time of divergence (as inferred from palaeoclimatic/palynological data), indicating constant AFLP divergence rates. As these rates did not differ significantly among species, a regression analysis based on the pooled data was utilized to generate a general AFLP rate. The application of this latter rate to AFLP data from other herbaceous plant species ( Minuartia biflora : Schönswetter et al . 2006 ; Nigella degenii : Comes et al . 2008 ) resulted in a plausible timing of the recolonization of the Svalbard Islands and the separation of populations from the Alps and Scandinavia ( Minuartia ), and of island population separation in the Aegean Archipelago ( Nigella ). Furthermore, the AFLP mutation rate obtained in our study is of the same magnitude as AFLP mutation rates published previously. The temporal limits of our AFLP rate, which is based on intraspecific vicariance events at shallow (i.e. late glacial/Early Holocene) time scales, remains to be tested.     

5个生姜品种的蛋白电泳指纹图谱研究

目的：研究5个生姜品种的鉴定。方法：利用蛋白质聚丙烯酰胺凝胶电泳（PAGE）指纹图谱分析、鉴别5个生姜品种。结果：5个样品的蛋白质PAGE指纹图谱具有一定差异。结论：PAGE指纹图谱可用于生姜品种鉴定与质量评价。     

中药XRD二阶导数指纹图谱的研究

以三种不同产地的丹参为研究对象,研究植物类中药XRD二阶导数指纹图谱方法学和植物类中药XRD二阶导数指纹图谱的特征。丹参XRD二阶导数指纹图谱具有峰位明确,峰型尖锐,特征性强的特点,不同产地丹参的差异性在二阶导数指纹图谱得以体现。通过相似度计算,三种丹参之间的相似度都小于0.8,可准确鉴定不同产地的丹参。结果表明:XRD二阶导数指纹图谱可用于植物类中药的XRD指纹图谱研究。     

秦艽提取物的高效液相色谱指纹图谱研究

本文采用梯度洗脱法建立了秦艽提取物的HPLC指纹图谱。流动相：甲醇-0．1％冰醋酸梯度洗脱（甲醇浓度变化：0.12min,20～45％;12～45min,45～100％）,检测波长：260nm,并采用国家药典委员会出版的“中药色谱指纹图谱相似度评价系统2004A版”软件进行谱图比较。结果10批次提取物指纹图谱相似度均大于0．90,建立了一种方便、准确、可靠的提取物指纹图谱质量控制方法。     

基于气相色谱-质谱联用技术的代谢组学方法在转植酸酶基因玉米代谢物指纹图谱分析中的应用

目的:建立气相色谱-质谱联用技术(GC-MS)的代谢组学方法,初步研究转基因株系与对照株系之间代谢物指纹图谱的差异性,为转基因作物安全的评价提供参考。方法:优化提取条件,考察色谱条件,并采用主成分分析(PCA)数据处理方法对转基因株系及对照进行模式识别。结果:优化了提取条件及色谱条件,建立了GC-MS的代谢组学方法,获得了小分子的代谢产物的表达谱,发现转基因与其对照之间呈现出显著性差异。结论:优化的GC-MS的代谢组学方法可以从代谢水平检测转基因作物,找出差异性,为转基因作物的检测与评价提供技术支持。