Genetic variability and principal component analysis of early seedling vigour traits in 3K rice germplasm

Early seedling vigour (ESV) is a crucial seed quality trait determined by rapid and uniform germination and early seedling establishment under various environmental conditions. Rapid establishment during the early stage of crop growth enhances crop’s competitive ability against weeds. In the present study, 226 3K rice germplasm accessions were investigated for ESV traits by paper roll towel method under laboratory conditions. The estimated heritability for vigour-based traits ranged from medium to high and significant genetic variability indicates complex inheritance of the traits governing ESV. Correlation analysis identified that seedling length (Sdl) and dry weight (DW) were highly associated with seedling vigour index-I (SVI) and seedling vigour index-II (SVII), respectively. In addition, principal component analysis revealed Sdl, SVI and SVII as the major contributing traits of ESV. The SVI and SVII traits identified five superior genotypes IRIS_313-11642, IRIS_313-9433, IRIS_313-8305, IRIS_313-9190 and IRIS_313-11420 that exhibited a higher seedling vigour index compared to check varieties. These 5 genotypes need to be further evaluated under field conditions to validate their performance and confirm their potential as donors for improving ESV in direct-seeded rice (DSR).