2022 Volume 67 Pages 1-6
Phosphorus (P) is one of the most essential nutrients for rice. In this study, low-P tolerance of 35 chromosome segment substitution lines (CSSLs), derived from japonica cultivar ‘Koshihikari’ as the recipient and indica cultivar ‘Habataki’ as the donor was evaluated at the seedling stage under low-P hydropic conditions. A low-P tolerant substitute line was found, which has a ‘Habataki’ segment on chromosome 6. In QTL analyses, an F2 population from the cross between japonica cultivar ‘Mizukagami’ and this substitute line was used, and QTLs for tiller number, maximum root length, and shoot fresh weight were detected near a simple sequence repeat (SSR) marker (RM6836) on chromosome 6. Fine mapping of the QTLs revealed that they are closely linked loci. Our results indicated that the ‘Habataki’ QTL alleles conferred low-P tolerance not only on ‘Koshihikari’ but also on ‘Mizukagami’, and would thus contribute to breeding for low-P adaptation for various Japanese cultivars.
