Phenotypic characterization of a female sterile mutant in rice
Phenotypic characterization of a female sterile mutant in rice
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DOI：
10.1111/j.1744-7909.2006.00228.x
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发表时间：
2006-03-01
影响因子：
11.4
通讯作者：
Li, P
中科院分区：
文献类型：
--
作者：
Li, SC;Yang, L;Li, P
首次在水稻(Oryza sativa L.SSP.)中发现了一个来自自发突变的雌性不育突变体。)恢复系202R。在正常开花的情况下，该突变体的结实率极低。当突变体作为花粉供体杂交时，种子正常结实；而当用作花粉接受者时，即使将不同品种的混合花粉粒撒在柱头上也得不到种子。突变体的小花由6个雄蕊和1个雌蕊组成，在雌雄器官中与野生型相同，只是不到10%的突变体在子房上有3个柱头。虽然该突变体的结实率较低，但其花粉育性约为87.1%，与野生型持平。此外，该突变体90%以上的成熟胚囊具有完整的内部结构。在授粉后的每个阶段，在突变胚囊中都没有发现精子、胚胎和胚乳，而没有完成受精的卵细胞却可以看到解体。通过荧光显微镜观察发现，在花柱传递组织中，花粉粒正常萌发，而花粉管异常伸长。突变的花粉管在花柱上表现出各种缺陷，如伸长减慢、伸长反转、伸长扭曲、顶端肿大或分枝顶端。因此，花柱中的花粉管停止生长，因此，花粉管不能到达胚囊，阻碍了双受精过程。根据这些观察结果，我们得出结论，该突变体被命名为fs-202R，是一种新型的水稻雌性不育突变，它导致花粉管伸长停止。
A female sterile mutant, derived from a spontaneous mutation, was first discovered in rice (Oryza sativa L. ssp. indica) restorer line 202R. With normal flowering, the mutant exhibits an extremely low seed-setting rate. When the mutant is crossed as a pollen donor, the seeds set normally; whereas when it is used as a pollen receiver, no seeds are obtained even with mixed pollen grains of different varieties sprinkled over the stigmas. The floret of the mutant, consisting of six stamens and one pistil, looks the same as that of the wild type in the male-female organs, except that less than 10% of the mutant florets have three stigmas on the ovary. Although the mutant has a low seed-setting rate, its pollen fertility is approximately 87.1%, which is equal to that of the wild type. In addition, more than 90% of the mature embryo sacs of the mutant have complete inner structures. At every stage after pollination, the sperm, embryo, and endosperm are not found in the mutant embryo sac, whereas the disintegration of the egg cell that does not accomplish fertilization is visible. Through observations with a fluorescence microscope, we have found that the pollen grains germinate normally, whereas the pollen tube abnormally elongates in the style-transmitting tissue. The mutant pollen tubes display various defects in the style, such as slower elongation, conversed elongation, distorted elongation, swollen tips, or branched tips. As a result, the growth of the pollen tubes ceases in the style, and, therefore, the pollen tubes cannot reach the embryo sac and the process of double fertilization is blocked. Based on these observations, we conclude that this mutant, designated as fs-202R, is a novel type of female sterile mutation in rice, which causes the arrest of the elongation of the pollen tube.