Yang Jie, Zhai Hu-Qu, Wang Cai-Lin, Zhong Wei-Gong, Zou Jiang-Shi, Ikehashi H, Wan Jian-Min
State Key Laboratory of Crop Genetics and Germplasm Enhancement, Rice Research Institute, Research Center of Jiangsu Plant Gene Engineering, Nanjing Agricultural University, Nanjing 210095, China.
Yi Chuan Xue Bao. 2005 May;32(5):507-13.
There existed a number of biological constraints in exploiting the heterosis of indica-japonica hybrid rice. The low-temperature-sensitive sterility (LTSS) of indica-japonica hybrid has become one of the major problems in indica-japonica hybrid rice breeding after the solution of poor fertility of the hybrids by the finding of wide-compatibility gene. Previous studies revealed that the LTSS might be caused by low-temperature-sensitive pollen sterility (LTSPS). However, the genetic basis of LTSPS remained unclear. To explore the genetic basis of LTSPS in indica-japonica hybrid rice, an F2 genetic population derived from 3037 (indica) and 02428 (japonica) was developed. At the booting stage, pollen fertility of F2 population together with parents were surveyed after the treatment with low temperature daily average of 21-23 degrees C. The linkage map was constructed containing 108 SSR markers distributed throughout the whole 12 chromosomes with average marker interval of 16.26 cM. Using software MapMaker/QTL, two putative QTLs, namely qLTSPS2 and qLTSPS5 on chromosomes 2 and 5 were detected by interval mapping, which could explain the phenotypic variation 15.6% and 11.9% respectively. The additive effects were 0.021 and 0.045, dominant effects were -0.246 and -0.215, and the degrees of dominance were 11.7 and 4.8, respectively for the two QTLs. Therefore, the mode of gene action in response to low-temperature stress was overdominance and LTSPS was mainly the result of interaction between the indica and japonica alleles within each locus. In addition, two-way ANOVA showed that the two QTLs acted essentially independent of each other in conditioning LTSPS.
在利用籼粳杂交水稻杂种优势方面存在一些生物学限制。在通过发现广亲和基因解决杂种育性差的问题后，籼粳杂交种的低温敏不育性（LTSS）已成为籼粳杂交水稻育种的主要问题之一。先前的研究表明，LTSS可能是由低温敏花粉不育性（LTSPS）引起的。然而，LTSPS的遗传基础仍不清楚。为了探究籼粳杂交水稻中LTSPS的遗传基础，构建了一个由3037（籼稻）和02428（粳稻）杂交得到的F2遗传群体。在孕穗期，对F2群体及其亲本在日平均温度为21 - 23摄氏度的低温处理后进行花粉育性调查。构建了包含108个SSR标记的连锁图谱，这些标记分布在整个12条染色体上，平均标记间隔为16.26 cM。使用MapMaker/QTL软件，通过区间作图在第2和第5染色体上检测到两个假定的QTL，即qLTSPS2和qLTSPS5，它们分别能解释15.6%和11.9%的表型变异。两个QTL的加性效应分别为0.021和0.045，显性效应分别为 - 0.246和 - 0.215，显性度分别为11.7和4.8。因此，响应低温胁迫的基因作用模式为超显性，LTSPS主要是每个位点上籼粳等位基因相互作用的结果。此外，双向方差分析表明，这两个QTL在调控LTSPS时基本相互独立起作用。
