Genetic Analysis and QTL Mapping of Mature Seed Culturability in Indica Rice

Genetic segregation analysis for mature seed culturability was conducted using recombinant inbred lines derived from a cross of indica rice, Yangdao 6 and Pei'ai 64s. Three indices of seed culturability, the frequency of callus induction, the frequency of brown callus and the increase of callus weight were investigated. A combined genetic map constructed with simple sequence repeat (SSR), sequence tag site (STS), cleaved amplified polymorphic sequences (CAPS) and single nucleotide polymorphism (SNP) markers covered a total distance of 1 732.5 cM, averaging approximately 12 cM between two neighboring loci. Three QTLs on chromosomes 7, 7 and 10 were detected for the frequency of callus induction; three QTLs on chromosomes 6, 7 and 9 were detected for the frequency of brown callus; and two QTLs on chromosomes 5 and 7 were detected for the increase of callus weight. Common QTLs mapped at the interval flanking RM5481 and RM6835 on chromosome 7 were identified to be involved in the frequency of callus induction and the frequency of brown callus, explaining 7.29% and 12.52% of phenotypic variation, respectively. A total of 14 epistatic effects were detected for the three indices of mature seed culturability.