Allelic interaction of F1 pollen sterility loci and abnormal chromosome behaviour caused pollen sterility in intersubspecific autotetraploid rice hybrids
Allelic interaction of F1 pollen sterility loci and abnormal chromosome behaviour caused pollen sterility in intersubspecific autotetraploid rice hybrids
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DOI：
10.1093/jxb/err098
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发表时间：
2011-08-01
影响因子：
6.9
通讯作者：
Lu, Y. G.
中科院分区：
文献类型：
--
作者：
He, J. H.;Shahid, M. Q.;Lu, Y. G.
同源四倍体水稻亚种间杂种具有许多提高水稻产量的特点，但结实率低是其利用的主要障碍。花粉不育性是造成亚种间杂交不育的重要因素之一。利用结实率变异较大的杂交种，研究了F-1花粉不育位点（S-a、S-b和S-c）之间的相互作用，以及F-1不育位点异常的染色体行为和等位基因相互作用对亚种间水稻杂种花粉育性和结实率的影响。结果表明，花粉不育位点之间的互作对同源四倍体杂交种的花粉育性有显著影响，并且随着F-1花粉不育位点等位基因互作的增加，花粉育性进一步降低。间期和瘦素期花粉育性较低的杂种在花粉母细胞减数分裂过程中超微结构和微管分布模式出现异常，说明花粉不育位点互作的生效时间很早。四倍体杂交种在四价体和二价体数量以及染色体构型上均存在极显著差异，且四价体数量随种子结实率的增加而减少。在PMC减数分裂的各个发育阶段都存在着染色体脱落、染色体滞后、染色体分离不同步、三裂变等染色体异常。这些异常在不育杂交种中均显著高于可育杂交种，说明花粉不育基因的相互作用会增加染色体异常，导致雄性配子部分流产，导致自四倍体水稻杂交种的结实率下降。
The intersubspecific hybrids of autotetraploid rice has many features that increase rice yield, but lower seed set is a major hindrance in its utilization. Pollen sterility is one of the most important factors which cause intersubspecific hybrid sterility. The hybrids with greater variation in seed set were used to study how the F-1 pollen sterile loci (S-a, S-b, and S-c) interact with each other and how abnormal chromosome behaviour and allelic interaction of F-1 sterility loci affect pollen fertility and seed set of intersubspecific autotetraploid rice hybrids. The results showed that interaction between pollen sterility loci have significant effects on the pollen fertility of autotetraploid hybrids, and pollen fertility further decreased with an increase in the allelic interaction of F-1 pollen sterility loci. Abnormal ultra-structure and microtubule distribution patterns during pollen mother cell (PMC) meiosis were found in the hybrids with low pollen fertility in interphase and leptotene, suggesting that the effect-time of pollen sterility loci interaction was very early. There were highly significant differences in the number of quadrivalents and bivalents, and in chromosome configuration among all the hybrids, and quadrivalents decreased with an increase in the seed set of autotetraploid hybrids. Many different kinds of chromosomal abnormalities, such as chromosome straggling, chromosome lagging, asynchrony of chromosome disjunction, and tri-fission were found during the various developmental stages of PMC meiosis. All these abnormalities were significantly higher in sterile hybrids than in fertile hybrids, suggesting that pollen sterility gene interactions tend to increase the chromosomal abnormalities which cause the partial abortion of male gametes and leads to the decline in the seed set of the autotetraploid rice hybrids.