东试早柚与沙田柚和水晶柚遗传背景比较

Comparative Analysis of Genetic Background of‘Dongshi Zaoyou’,‘Shatianyou’and‘Shuijingyou’Pummelos

‘东试早柚’是实生选育出的柚品种,在云南省热带地区种植,具有早熟、丰产、无籽等优点,然而其来源至今尚未厘清,在品种权意识淡薄的栽培地区产生了许多经济纠纷。因此,解析‘东试早柚’的遗传来源对保护和利用该品种均具有重要意义。以西双版纳‘东试早柚’及其相近品种‘沙田柚’‘水晶柚’为材料,利用分子标记和生物信息等手段探究了3个品种的遗传背景差异。结果显示,‘东试早柚’与‘水晶柚’间杂交不亲和,而与‘沙田柚’杂交亲和;‘东试早柚’和‘水晶柚’的自交不亲和S位点基因型均为S5S6,而‘沙田柚’为S1S2;‘东试早柚’和‘水晶柚’全基因组SNP密度分布高度相似,SNP聚类分析将‘东试早柚’和‘水晶柚’聚为一类,而与‘沙田柚’显著区分。此外,2对InDel多态性标记也可明显区分‘东试早柚’与‘沙田柚’。因此,本研究结果认为‘东试早柚’与‘水晶柚’遗传背景更为相近,而与‘沙田柚’遗传距离较远、相差很大。

‘Dongshi Zaoyou’,a new pummelo cultivar selected from pummelo seedlings,is mainly cultivated in the tropical areas of Yunnan Province.It has good characteristics such as early-maturing,high-yielding,seedless and etc.However,the genetic origin of‘Dongshi Zaoyou’pummelo has not yet been clarified,which was unfavorable to its protection and utilization.In this study,the cross-compatibility test and molecular markers including self-incompatibility S-genotype,SNP and InDels were used to explore the genetic background differences between‘Dongshi Zaoyou’pummelo and its two similar cultivars‘Shatianyou’,‘Shuijingyou’.The pollination experiments revealed the cross-incompatibility between‘Dongshi Zaoyou’pummelo and‘Shuijingyou’pummelo while the cross-compatibility between‘Dongshi Zaoyou’pummelo and‘Shatianyou’pummelo.Accordingly,S-genotype of‘Dongshi Zaoyou’pummelo was judged to be S5S6,the same as that of‘Shuijingyou’pummelo(S5S6),while different from that of‘Shatianyou’pummelo(S1S2).Based on the genome resequencing data,the genome-wide SNP density distribution of three pummelo cultivars were then plotted and compared.The results showed that‘Dongshi Zaoyou’pummelo and‘Shuijingyou’pummelo had highly similar SNP density and clustered into a group,but they both were significantly different from‘Shatianyou’pummelo.In addition,two InDel polymorphic markers could clearly distinguish‘Dongshi Zaoyou’pummelo from‘Shatianyou’pummelo.Collectively,it could be concluded that‘Dongshi Zaoyou’pummelo showed a closer relationship to‘Shuijingyou’pummelo than‘Shatianyou’pummelo.