The yield potentiality of kharif rice is not completely used even under well-irrigated agro-ecosystem, mainly due to low irradiance by overcast cloud throughout the growing season in eastern India. We observed more than 50% yield reduction compared to the performance of 100 high-yield genotypes for consecutive three years both under open and 30–35% reduced light intensity, mainly by 34%, 25% and 12% reduction of panicle number, grains per panicle and test weight. As per the analysis of variance, genotypic variance explained 39% of the total yield-variation under shade with 58% heritability. Overall, the maintenance of equal panicle per plant in both open and shade has the highest association with shade tolerance. Purnendu, Sashi and Pantdhan19 showed less than 28% yield-reduction by maintenance or even by increasing grain numbers under shade and test weight. On the other hand, maintenance of an equal number of panicle under both situations was the key to the tolerance of Bhasamanik, Sasarang, Rudra and Swarnaprabha. As compared to open, we noticed the improvement of chlorophyll a and b under shade but saw a poor correlation with the shade tolerance index. Comparing the net photosynthesis rate (P n ) in eight genotypes, we found the best tolerant line ranked last with least P n at low light intensity (<400 µ mol m −2 s −1 ). We also identified diverse parental combinations between newly identified shade tolerant and abiotic stress tolerant high-yielding rice lines following diversity analysis using 54 simple-sequence repeats. Thus, the selected tolerant lines from a large set of genotypes with different adjustment ability to keep up high yield under low light intensity can be used for physiological, molecular analysis as well as pyramiding of traits.

中文翻译：

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大田条件下耐弱光水稻基因型及其在各种非生物胁迫耐受系中基于SSR的多样性的鉴定和分析

即使在灌溉良好的农业生态系统下，kharif 水稻的产量潜力也没有得到完全利用，这主要是由于印度东部整个生长季节阴云的低辐照度。我们观察到与 100 个高产基因型连续三年在开放和 30-35% 的光照强度下的表现相比，产量减少了 50% 以上，主要是穗数减少了 34%、25% 和 12%每穗和测试重量。根据方差分析，基因型方差解释了遮荫下总产量变异的 39%，遗传力为 58%。总体而言，在开放和遮荫下每株保持相等的穗数与耐荫性的相关性最高。普南杜，Sashi 和 Pantdhan19 显示，通过维护或什至通过增加遮荫和测试重量下的谷物数量，减产幅度不到 28%。另一方面，在两种情况下保持相同数量的穗是Bhasamanik、Sasarang、Rudra和Swarnaprabha容忍的关键。与开放相比，我们注意到在遮荫下叶绿素 a 和 b 有所改善，但与耐荫指数的相关性较差。比较八种基因型的净光合作用速率 (P n )，我们发现在低光照强度 (<400 µ mol m -2 s -1 ) 下，耐受性最好的品系排在最后，P n 最少。在使用 54 个简单序列重复进行多样性分析后，我们还确定了新鉴定的耐阴和耐非生物胁迫的高产水稻品系之间的不同亲本组合。因此，