‘东试早柚’果实无核成因探究

Studies on seedlessness mechanism in‘Dongshi Zaoyou’pummelo

为明确‘东试早柚’果实无核成因,以‘东试早柚’及其杂交群体为试材,利用醋酸洋红和苯胺蓝染色法、杂交授粉及分子标记等手段探究‘东试早柚’无核原因。结果显示:‘东试早柚’的花结构完整,花粉活力及萌发率分别为94.80%和86.20%;‘东试早柚’自交表现为不亲和,而与‘沙田柚’杂交亲和;利用S5、S6基因型分子标记从‘沙田柚’ב东试早柚’的175株杂交子代中共鉴定出F1代杂种164株,排除了‘东试早柚’雄性不育的可能;连续2 a田间试验观察显示,‘东试早柚’刺激性单性结实和天然单性结实的平均座果率分别为13.04%和25.56%。结果表明,‘东试早柚’自交不亲和并具有一定的单性结实能力是导致其无核的主要成因。

‘Dongshi Zaoyou’pummelo and its hybrid offsprings,methods including magenta acetate staining and aniline blue staining,cross-pollination,and molecular markers were used to study the mecha⁃nism of seedlessness in‘Dongshi Zaoyou’pummelo.The results showed that the floral structure of‘Dong⁃shi Zaoyou’pummelo was intact,with pollen vitality and germination rates of 94.80%and 86.20%,respec⁃tively.The self-pollination of‘Dongshi Zaoyou’pummelo showed incompatibility,while cross-pollination with‘Shatianyou’pummelo showed compatibility.A total of 164 F1 hybrids were identified from 175 hy⁃brid offsprings of‘Shatianyou’pummeloבDongshi Zaoyou’pummelo with S5/S6 molecular marker ge⁃notyping,ruling out the possibility of male sterility in‘Dongshi Zaoyou’pummelo.The results of observa⁃tion for two consecutive years showed that the mean fruit setting rates of stimulating parthenocarpy and nat⁃ural parthenocarpy in‘Dongshi Zaoyou’pummelo was 13.04%and 25.56%,respectively.It is indicated that the main reason for the seedless development of‘Dongshi Zaoyou’pummelo is its self-incompatibility and certain ability to produce parthenocarpy.