DNA marker assisted gentic analysis of early vigor related traits in rice Oryza sativa L

Abstract

Upland rice plays a major role in the sustainable food security of the country. Early newlinevigour trait is important in the drill-sown rice for weed suppression as well as initial newlineestablishment. The IR64/Azucena was used as a reference population to identify QTLs for newlineearly vigour related traits. The SSR markers flanking QTLs in IR64/Azucena and other newlinepopulations were used for validation in the new populations (BPT5204/A67 and newlineBPT5204/Dodiga). Twenty-two QTLs distributed on chromosomes 1 to 6 were identified for newlinedifferent vigour related traits. The QTLs controlling germination were located on newlinechromosome1 in the region RM5-RM306 near to a-amalyse genes which control germination. newlineThe congruence of QTLs was observed on Chromosome 5 in the region RM87-RM334 for newlinerate of germination, seedling dry weight and vigour index. The additive effect was both newlinepositive and negative indicating contribution from both parents. Transgressive segregants newlinewere observed for different traits in all the populations revealing contribution of favourable newlinealleles from both parents. The narrow sense heritability for shoot length was comparable in newlinethe two crosses viz., BPT 5204/A67 (29.2%) and BPT 5204/Dodiga (24.1%) while realized newlineheritability was higher in BPT5204/Dodiga (48.7%) as compared to BPT 5204/A67 (15.5%). newlineOut of 42 Simple Sequence Repeats (SSR) markers assessed, 24 were polymorphic between newlineBPT 5204 and Dodiga and 20 markers were polymorphic between BPT 5204 and A67. The newlinepolymorphic markers were screened in F2:F3 populations. The single marker analysis was newlineemployed to assess the association between marker and trait. RM253 (Chromosome 6) was newlineassociated with the shoot length at 10th and 14th newlineDAS with 9.6% and 10.1% contribution in BPT5204/A67. RM178 (Chromosome 5) was newlineassociated with shoot length (18%) and root length (11.2%) at 10th DAS in BPT5204/Dodiga.