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.