Abstract:
Submergence tolerance in rice varieties is crucial for maintaining stable yields in low land areas, where re currence of flooding is a constant phenomenon during monsoon. We have conducted detailed physiological and
genotyping studies of 27 rice genotypes and one wild rice relative, popularly grown in low land areas of the two
major rice growing states of eastern India, West Bengal and Odisha with a focus on submergence tolerance traits
and Sub1 loci. We found that these genotypes show varying degree (50–100%) survival rate during post sub mergence recovery period, and high degree of polymorphism in the Sub1 linked rice microsatellite loci RM219
and RM7175. Detailed allelic diversity study of Sub1A loci suggests that rice varieties IR42, Panibhasha, Khoda
and Kalaputia share a common allele that is different from FR13A, Keralasundari, Bhashakalmi, Kumrogore. Two
other genotypes Meghi and Khoda shares both alleles of Sub1A loci (present in IR42 and FR13A groups) in
addition to a new variant. Detailed sequence analysis of the amplified product for the Sub1A loci from these
genotypes showed several single nucleotide changes with respect to reference Oryza sativa Sub1A loci
(DQ011598). Three rice genotypes (Meghi, Bhashakalmi and Keralasundari) showed beneficial properties in
relation to induced submergence stress and can be considered as valuable genetic source in context of utilization
of natural rice genetic resources in breeding program for submergence tolerance
