Diversity of Indian rice cultivars and landraces for seedling vigour and their association for yield related traits

Rediscovery of the valuable genes which are lost during breeding and domestication of crop species, helps in the development of climate-smart varieties with high yield and tolerance to various emerging stresses. Seedling vigour is an important trait that helps in the early survival of the crop in adverse environments and in changing cultivation practices. The present investigation was carried out to explore the variability available in Indian rice cultivars and landraces for seedling vigour and yield related traits. Significant genetic variance was observed in the germplasm for targeted traits under study showing their potential in further breeding programmes. High heritability estimates were recorded for seedling vigour related traits. Trait association revealed that single plant yield had a positive significant correlation with productive tiller number, the total number of grains per panicle, tiller number, the total number of filled grains per panicle, plant height, flag leaf length and panicle length. Significant correlation was found between single plant yield and seedling vigour indices. Seedling vigour traits showed high positive and direct effects with yield traits. The molecular screening of the genotypes were carried out using functional markers associated to the yield genes Gn1a, Ghd7 , GS5 , SPIKE and SD1 . Based on genotypic data obtained from this study, genotypes were grouped into 6 major clusters and the groups showed a substantial variation based on seedling vigour traits and yield parameters like panicle weight and grains per panicle. This study indicates the potential of cultivars and landraces for simultaneous improvement of yield and seedling vigour traits for the changing climate scenario.