Abstract:
Breeding for salt tolerance is the most promising
approach to enhance the productivity of saline prone areas.
However, polygenic inheritance of salt tolerance in rice
acts as a bottleneck in conventional breeding for salt toler ance. Hence, we set our goals to construct a single nucleo tide polymorphism (SNP)-based molecular map employing
high-throughput SNP marker technology and to investigate
salinity tolerant QTLs with closest flanking markers using
an elite rice background. Seedling stage salinity responses
were assessed in a population of 281 recombinant inbred
lines (RILs) derived from the cross between At354 (salt
tolerant) and Bg352 (salt susceptible), by 11 morpho physiological indices under a hydroponic system. Selected
extreme 94 RILs were genotyped using Illumina Infinium
rice 6K SNP array and densely saturated molecular map
spanning 1460.81 cM of the rice genome with an average using 1135 polymorphic SNP markers. The results revealed
83 significant QTLs for 11 salt responsive traits explaining
12.5–46.7 % of phenotypic variation in respective traits. Of
them, 72 QTLs responsible for 10 traits were co-localized
together forming 14 QTL hotspots at 14 different genomic
regions. The all QTL hotspots were flanked less than 1 Mb
intervals and therefore the SNP loci associated with these
QTL hotspots would be important in candidate gene dis covery for salt tolerance.
interval of 1.29 cM between marker loci was constructed
