Phenotypic evaluation of seedling vigour-related traits in a set of rice lines

Abstract

Under the changing climatic conditions, depleting nutrients and water scarcity, the dry-direct seeded rice (DDSR) with an aerobic system of cultivation is gaining ground in India. The uniform establishment ofseedlings is critically dependent on the seedling vigour and high seedling vigour provides better uptake of nutrients with uniform plant growth. With an aim to identify rice lines exhibiting high seedling vigour traits, we phenotyped the seedling vigour index-related traits viz., germination percentage (GP), mesocotyl length (ML), coleoptile length (CL), root and shoot fresh and dry weights in a set of rice lines consistingof introgression lines, landraces, mutant lines and popular varieties using the paper towel method. ANOVA revealed high significant variation for all the traits including seedling vigour index-I (SVI-I) and seedling vigour index-II (SVI-II). Significant positive intercorrelation was recorded between two sub-traits for establishment of seedling viz. coleoptile length and mesocotyl length. The rice lines viz., ATR-486, ATR-473, ATR-385, ATR-279, ATR-472, ATR-397, ATR-275, KK-12 and ATR-387 exhibited comparatively higher CL, ML, SVI-I and SVI-II than all the checks used in the present study. The identified lines exhibiting better seedling vigour traits are promising genetic resources that can be deployed in breeding programs for improving adaptability under DDSR conditions.