Using agro-morphological characters and microsatellite markers, advance breeding lines of rice were discriminated for their ability to tolerate drought stress at reproductive stage. Experimental materials consisting of 17 advance breeding lines and a check were evaluated in randomized block design with three replications under irrigated condition and drought condition created under rainout shelter during three consecutive years. An analysis of variance revealed significant differences among the genotypes for all the ten agro-morphological characters evaluated under both the conditions across the years. Principal component analysis showed the relative importance of root length, number of tillers per plant, number of grains per panicle, harvest index and grain yield per plant among agro-morphological characters and stress tolerance level, stress susceptibility index, stress tolerance index and drought tolerance efficiency among drought tolerance indices as the important classification variables. Relative mean performance in respect of grain yield as well as drought tolerance indices reflected remarkably greater degree of drought tolerance in 11 advance breeding lines and the check, discriminating them from remaining entries under evaluation. Utilizing a panel of 32 microsatellite primers, selective amplification of targeted genomic regions revealed that the primers RM 72, RM 163, RM 212, RM 225, RM 231, RM 302, RM 327, RM 518, RM 521, RM 555, RM 1349, RM 3549 and RM 5443 were highly informative with greater gene diversity and discrimination ability. Hierarchical cluster analysis based on molecular profiles discriminated the entries into five genotypic groups and drought tolerant entries were accommodated into three distinct groups with remarkably greater efficiency (85.7%). Principal coordinate analysis based two dimensional plots of microsatellites dependent genetic profiles displayed a very close correspondence with the genotypic clustering pattern revealed from a perusal of dendrogram. Sequential exclusion of primers in cluster analysis led to identification of RM 212, RM 231, RM 324, RM 431, RM 521, RM 3549 and RM 6374 as the most useful primers for discrimination of drought tolerant and susceptible lines of rice. Molecular profiling based on these markers can be utilized as efficient tools for discrimination and identification of drought tolerant lines.

中文翻译：

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利用微卫星标记的水稻先进育种系中与耐旱性相关的分子谱分析

利用农业形态学特征和微卫星标记，区分了水稻先进育种品种在繁殖期耐旱的能力。在连续三年的灌溉条件下和干旱条件下在防雨棚中制作了三个重复样本，在随机区组设计中评估了由17个先进育种线和一个检查组成的实验材料。方差分析显示，在这两种条件下，多年来评估的所有十个农业形态特征的基因型之间均存在显着差异。主成分分析表明，根系长度，单株分till数，单穗粒数，收成指数和单株产量在农业形态特征和胁迫耐性水平之间具有相对重要性，耐旱指数中的抗旱指数，抗旱指数和抗旱效率是重要的分类变量。相对于谷物单产的平均表现以及耐旱指数，反映出11个高级育种品系和对照的耐旱性明显提高，从而将其与待评估的其余品种区分开来。利用一组32个微卫星引物，对目标基因组区域进行选择性扩增，发现引物RM 72，RM 163，RM 212，RM 225，RM 231，RM 302，RM 327，RM 518，RM 521，RM 555，RM 1349 ，RM 3549和RM 5443具有较高的信息多样性，具有更高的基因多样性和区分能力。基于分子谱的层次聚类分析将条目分为五个基因型组，将耐旱条目分为三个不同的组，效率显着提高（85.7％）。基于主坐标分析的微卫星相关遗传图谱的二维图显示了与树状图细读所揭示的基因型聚类模式非常接近。在聚类分析中顺序排除引物导致鉴定出RM 212，RM 231，RM 324，RM 431，RM 521，RM 3549和RM 6374是区分水稻耐旱和易感品系的最有用的引物。基于这些标记的分子谱分析可以用作区分和鉴定耐旱品系的有效工具。