水稻萌发耐淹性的遗传分析

水稻(Oryza sativa)萌发耐淹性受到复杂的网络调控, 其分子机制不同于苗期耐淹性的相关机制, 萌发耐淹性的强弱影响着直播稻的成苗率。通过对256份水稻核心种质的萌发耐淹性评估, 发现粳稻和籼稻之间的萌发耐淹性差异并不显著, 都存在广泛的遗传变异。利用以粳稻R0380为供体亲本, 籼稻RP2334为轮回亲本的170个高代回交自交系构建含146个分子标记的连锁图谱, 以低氧胚芽鞘长度为性状指标, 通过复合区间作图法检测到影响萌发耐淹性的4个QTLs(quantitative trait loci), 分别定位于第2(2个)、3(1个)和8号(1个)染色体。贡献率最大的QTL为qGS2.2, 其值为17.34%, 增效等位基因来自轮回亲本籼稻RP2334; 其余3个QTLs的增效等位基因均来自供体亲本粳稻R0380, 贡献率分别为12.86%、9.37%和14.60%。

Genetic Analysis of Seed Germinability Under Submergence in Rice

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.