Molecular diversity and segregation distortion measured by SSR markers in a new plant type based recombinant inbred line population of rice

A mapping population of 310 F-7 recombinant inbred lines (RILs) developed by crossing a new plant type derivative, Pusa1266 with Jaya was used for construction of linkage map and dissection of its genome for heterozygosity and segregation distortion by using SSR (Simple Sequence Repeat) markers. A set of 162 polymorphic markers between parents were utilized to genotype entire RIL population. Twenty three markers (14.20%) showed significant segregation distortion from expected 1:1 segregation ratio. A linkage map was constructed with 126 markers on 12 chromosomes representing total map length of 2023.1 cM with an average marker interval of 19.64 cM. Out of 310 RILs, 7 lines (2.3%) were highly skewed towards Pusa1266 and 6 lines (1.9%) towards Jaya. Heterozygosity was absent at 42 marker loci, moderate at 37 marker loci and high at 47 marker loci. The regions with higher average rate of recombination were observed on long arm of chromosome 3, 5, 6, 7, 8 and 10. The population had an average genome content of 46.7% of Pusa1266 and 49.3% of Jaya. The Pusa1266 x Jaya RIL population was found to be a good mapping population characterized by almost equal average genomlc content of both parents, relatively low frequencies of heterozygosity and low percentage of skewed markers will facilitate molecular mapping of QTLs for the agronomic traits segregating in this population.