‘金坠梨’自交亲和性突变机制的初步研究  

Mutational Mechanism of Self-compatible Pear Cultivar‘Jinzhuili' (Pyrus bretschneideri)

作　　者：吴华清[1] 张绍铃[1] 吴巨友[1] 王迎涛[1] 吴俊[1] 

机构地区：[1]南京农业大学园艺学院,南京210095

出　　处：《园艺学报》2007年第2期295-300,共6页Acta Horticulturae Sinica

基　　金：国家教育部科技重点项目(105089);国家自然科学基金项目(30671437)

摘　　要：自交不亲和性品种鸭梨的芽变品种‘金坠梨’自花授粉能结实,但其自交亲和性突变机制至今不祥。本研究结果表明,鸭梨自花授粉结实率仅2%,自花花粉管在花柱中上部已经停止生长,而金坠梨自花授粉结实率高达76%,自花的花粉管能正常生长至花柱基部;鸭梨花柱能够接受金坠梨花粉并受精结实,而金坠梨花柱却与鸭梨花粉杂交不亲和;进一步鉴定出了鸭梨和金坠梨基于S-RNase基因的S基因型,发现两者S基因型相同,均为S21S34;通过克隆两品种S-RNase基因cDNA全长序列并进行比较分析发现,该两品种的1对雌蕊S-RNase基因在核苷酸序列上完全相同,且S-RNase基因均正常表达,表达量没有明显差异,从分子水平上证实了金坠梨在花柱方面和鸭梨并无差异,可能是花粉S基因发生突变,导致了自交不亲和性功能的丧失,表现出自花授粉能够结实。Jinzhuili （Z） is a naturally occurred self-compatible （SC） mutant from Yali （Y）, a Chinanative leading cuhivar displaying typical gametophytic self-incompatibility （GSI）. How Z mutated to SC is unclear to date. In the present study, field pollination tests were carried out under four crosses （Z selfed, Yselfed, Z × Y and Y× Z）, and fruit setting percentage determined and pollen tube growth inspected under fluorescent microscope. It was observed that more than 76% flowers set fruits and many pollen tubes grew down to the base of style in crosses of Z and YXZ, whereas fruit setting did not occurred and most pollen tubes were arrested at the upper part of style in the cross Y and ZXY. These results indicated that both Y and Z functioned normally in SI response on the stylar part and could reject competent Y pollen, but accepted Z pol- len o Further molecular analyses revealed that both Y and Z harbored S21- and S34- RNase, transcribed normally and were identical to one another in mRNA sequences of two S-RNases. All these data suggested that Z most likely lost pollen SI function, and its style behave normally in SI response as that of its wild type Y did. How pollen of Z mutated needs to be further investigated.

关 键 词：梨 自交亲和性 自交不亲和性 S-RNASE基因 变异 授粉 

分 类 号：S661.2[农业科学—果树学]