Qi Yong-Jie, Wang Ying-Tao, Han Yan-Xiao, Qiang Sheng, Wu Jun, Tao Shu-Tian, Zhang Shao-Ling, Wu Hua-Qing
College of Horticulture, State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, 210095 Jiangsu, China.
Genetica. 2011 Sep;139(9):1149-58. doi: 10.1007/s10709-011-9617-6. Epub 2011 Nov 17.
The pear cultivar 'Zaoguan' (S(4)S(34)) is the a self-compatible descendant of 'Yali' (S(21)S(34)) × 'Qingyun'(S(4)S(9)). Two self-incompatible cultivars 'Xinya' and 'Yaqing', also S-genotyped as S(4)S(34) for the S-RNase gene, were used as controls. Field pollination data revealed that 'Zaoguan' displayed SC, whereas 'Xinya' and 'Yaqing' showed self-incompatibility (SI) upon self-pollination. Reciprocal pollinations between the varieties showed that most of the 'Zaoguan' flowers pollinated with 'Xinya' or 'Yaqing' pollen set fruits but that few of the 'Xinya' or 'Yaqing' flowers set fruit when pollinated with 'Zaoguan' pollen. The pollen performance was monitored with fluorescence microscopy, and we observed that 'Zaoguan' accepted self-pollen as well as 'Xinya' or 'Yaqing' pollen, whereas 'Xinya' or 'Yaqing' rejected self-pollen and 'Zaoguan' pollen. The S(34)-RNase but not the S(4)-RNase could be detected in all selfed progeny of 'Zaoguan'. Comparisons of the 2D-PAGE profiles of the stylar extracts from the three cultivars showed that the S(4)-RNase protein expressed normally, but the S(34)-RNase of 'Zaoguan' was not found. Thus, we concluded that the stylar S(34) products were defective in 'Zaoguan' and that the S (4)-allele functioned normally. The nucleotide sequences of the S(4)- and S(34)-RNase of 'Zaoguan' showed no differences from those of 'Xinya' or 'Yaqing', and they transcribed normally. These results indicate that SC in 'Zaoguan' was due to the loss of the S(34)-RNase caused by unknown post-transcriptional factors.
梨品种‘早冠’（S(4)S(34)）是‘鸭梨’（S(21)S(34)）ב青孕’（S(4)S(9)）的自交亲和后代。另外两个自交不亲和品种‘新雅’和‘鸭青’，其S-RNase基因的S基因型也为S(4)S(34)，用作对照。田间授粉数据显示，‘早冠’表现出自交亲和，而‘新雅’和‘鸭青’自花授粉时表现出自交不亲和（SI）。品种间的正反交表明，大多数用‘新雅’或‘鸭青’花粉授粉的‘早冠’花朵坐果，但用‘早冠’花粉授粉时，‘新雅’或‘鸭青’的花朵很少坐果。用荧光显微镜监测花粉表现，我们观察到‘早冠’接受自花花粉以及‘新雅’或‘鸭青’花粉，而‘新雅’或‘鸭青’排斥自花花粉和‘早冠’花粉。在‘早冠’的所有自交后代中都能检测到S(34)-RNase，而检测不到S(4)-RNase。对三个品种花柱提取物的二维聚丙烯酰胺凝胶电泳图谱比较表明，S(4)-RNase蛋白正常表达，但未发现‘早冠’的S(34)-RNase。因此，我们得出结论，‘早冠’花柱中的S(34)产物存在缺陷，而S(4)等位基因功能正常。‘早冠’的S(4)-和S(34)-RNase的核苷酸序列与‘新雅’或‘鸭青’的核苷酸序列没有差异，且它们正常转录。这些结果表明，‘早冠’的自交亲和是由于未知的转录后因素导致S(34)-RNase缺失所致。
