National Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, 210095 Nanjing, China.
Planta. 2010 Feb;231(3):559-70. doi: 10.1007/s00425-009-1063-7. Epub 2009 Nov 28.
Weedy rice represents an important resource for rice improvement. The F(1) hybrid between the japonica wide compatibility rice cultivar 02428 and a weedy rice accession from Yunnan province (SW China) suffered from pollen sterility. Pollen abortion in the hybrid occurred at the early bicellular pollen stage, as a result of mitotic failure in the microspore, although the tapetum developed normally. Genetic mapping in a BC(1)F(1) population (02428//Yunnan weedy rice (YWR)/02428) showed that a major QTL for hybrid pollen sterility (qPS-1) was present on chromosome 1. qPS-1 was fine-mapped to a 110 kb region known to contain the hybrid pollen sterility gene Sa, making it likely that qPS-1 is either identical to, or allelic with Sa. Interestingly, F(1) hybrid indicated that Dular and IR36 were assumed to carry the sterility-neutral allele, Sa ( n ). Re-sequencing SaM and SaF, the two component genes present at Sa, suggested that variation for IR36 and Dular may be responsible for the loss of male sterility, and the qPS-1 sequence might be derived from wild rice or indica cultivars. A phylogenetic analysis based on microsatellite genotyping suggested that the YWR accession is more closely related to wild rice and indica type cultivars than to japonica types. Thus it is probable that the YWR accession evolved from a spontaneous hybrid between wild rice and an ancient cultivated strain of domesticated rice.
杂草稻是水稻改良的重要资源。粳稻广亲和品种 02428 与来自中国云南省（西南地区）的杂草稻杂交 F1 杂种花粉败育。杂种花粉败育发生在早期二细胞花粉期，由于小孢子有丝分裂失败，尽管绒毡层发育正常。在 02428//云南杂草稻（YWR）/02428 的 BC1F1 群体中进行的遗传作图表明，杂种花粉不育的一个主要 QTL（qPS-1）位于 1 号染色体上。qPS-1 被精细定位到一个 110kb 的区域，该区域已知包含杂种花粉不育基因 Sa，因此 qPS-1 很可能与 Sa 相同或等位。有趣的是，F1 杂种表明 Dular 和 IR36 被认为携带不育中性等位基因 Sa（n）。对 SaM 和 SaF 两个组分基因的重测序表明，IR36 和 Dular 的变异可能导致雄性不育的丧失，qPS-1 序列可能来自野生稻或籼稻品种。基于微卫星基因型分析的系统发育分析表明，YWR 品系与野生稻和籼稻类型比与粳稻类型更为密切相关。因此，YWR 品系很可能是由野生稻和古老的驯化水稻品种之间的自发杂交进化而来。
