Genetic Analysis of Seed Germinability Under Submergence in Rice
水稻萌发耐淹性的遗传分析

Submergence tolerance during germination in rice is regulated by a complex molecular network, the molecular mechanism of which is different from that of submergence tolerance during seedling stage. Germinability under submergence (GS) considerably affects seedling establishment of direct-seeded rice. According to the GS of 256 accessions of the rice core collection, both japonica and indica have high genetic variation of GS with no significant difference in GS. We constructed a linkage map of 146 molecular markers from 170 advanced inbred lines from a backcross between R0380 (japonica) and RP2334 (indica) and used composite interval mapping to detect quantitative trait loci (QTL) associated with GS (coleoptile length under hypoxia). We found 4 QTLs on chromosome 2 (2 QTLs), 3 (1 QTL), and 8 (1 QTL). The positive allele of qGS2.2, which explained 17.34% of the phenotypic variation, was from RP2334, and alleles for the other 3 QTLs came from R0380, which explained 12.86%, 9.37% and 14.60%, respectively, of the phenotypic variation.