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Seed storability in rice (Oryza sativa L.) is an important agronomic trait. Two segregating populations with N22 (indica) as a common parent, viz. a set of 122 backcross-inbred lines (BILs) derived from the backcross Nanjing35 (japonica)/N22//Nanjing35 and another population comprising 189 recombinant inbred lines (RILs) from the cross of USSR5 (japonica) and N22, were studied to detect quantitative trait loci (QTL) controlling seed storability. Germination percentage (GP) was used to evaluate seed storability after aging treated under three different conditions, viz. natural, artificial and combined aging treatments. A total of seven QTLs were identified on chromosomes 1, 2, 5, 6 and 9. Among them, a major QTL, qSSn-9, was common in the two populations. In contrast, four QTLs (qSSnj-2-1, qSSn-2-2, qSSn-5 and qSSn-6) were detected in BILs and the QTL qSSn-1 was identified in RILs, which was a new QTL for seed storability. The N22-derived alleles increased the seed storability at all the loci except qSSnj-2-1. We also investigated the effect of QTLs using five selected lines with high storability from BILs and verified qSSn-5 with a near-isogenic line (NIL). These results provide an opportunity for pyramiding or map-based cloning major QTLs for seed storability in rice.

Seed aging or deterioration in rice (Oryza sativa L.) is a major problem for agronomic production and germplasm preservation. Deciphering the genetic mechanism involved in seed aging and improving seed storability is therefore a vital goal for rice breeding. A set of 85 backcross inbred lines derived from the backcross ‘Sasanishiki’ (japonica cv.)/‘Habataki’ (an indica cv. with strong seed storability)//‘Sasanishiki’ was used here to detect quantitative trait locus (QTL) controlling seed storability. Seeds were treated under natural (conventional storage for 48 months) and artificial aging storage conditions (i.e. increased temperature and relative humidity) and germination rate was used to evaluate seed storability. A total of thirteen QTLs for seed storability were identified on chromosomes 1, 2, 3, 4, 5, 7, 11 and 12, respectively. Among them, two QTLs, viz. qSSh-2-1 and qSSh-2-2, were repeatedly detected in both treatment conditions. In contrast, four (qSSh-4, qSSs-5-1, qSSs-5-2 and qSSh-12) and seven QTLs (qSSh-1, qSSh-3-1, qSSh-3-2, qSSh-3-3, qSSh-7-1, qSSh-7-2 and qSSh-11) were detected only once in natural and artificial aging treatments, respectively. The ‘Habataki’-derived alleles were observed to increase seed storability at all the loci except qSSs-5-1 and qSSs-5-2. The existence of QTLs qSSh-1, qSSh-3-1, qSSh-3-2, qSSh-3-3, qSSh-4, qSSh-7-1, qSSh-7-2 and qSSh-11 was confirmed using Habataki chromosome segment substitution lines in a Sasanishiki genetic background. These results provide an opportunity for map-based cloning of major QTLs for seed storability, thereby gaining an understanding of seed storability in rice and possibilities for its improvement.