利用SNP标记鉴定荔枝杂种后代

Identification of Litchi(Litchi chinensis Sonn.) Hybrids by SNP Markers

本研究利用SNP标记对‘白糖罂’ב禾虾串’、‘禾虾串’ב白糖罂’及‘白糖罂’ב无核荔’3个荔枝杂交组合F_1代共131个单株的真实性进行了鉴定。利用基质辅助激光解吸电离飞行时间质谱技术,从155个均匀分布在荔枝基因组的SNP标记中筛选出在上述杂交亲本中表现为不同纯合基因型的SNP位点;结合高分辨率熔解曲线技术,利用上述SNP位点对各个组合的杂交苗F_1代进行了SNP分型。SNP分型结果显示,杂种F1代的基因型呈现杂合基因型、父本纯合基因型和母本纯合基因型3类。针对‘白糖罂’ב禾虾串’、‘禾虾串’ב白糖罂’及‘白糖罂’ב无核荔’3个杂交组合,均只利用一对纯合共显性SNP标记即成功完成所有F_1代单株的鉴定,真杂种率分别为93.6%、96.8%和72.5%。SNP标记首次成功应用于荔枝3个F_1杂交群体的鉴定,为今后荔枝杂交育种中的真假杂种鉴定提供了可借鉴手段。

In this study,authenticity of 131 individual F_1 hybrid of three litchi cross combinations of‘Baitangying'בHexiachuan',‘Hexiachuan'בBaitangying'and‘Baitangying'בWuheli'were analyzed using single nucleotide polymorphism(SNP) markers.Out of 155 SNPs which were evenly distributed across litchi genome,SNP markers which showed different homozygous loci in parental cultivars were selected for each cross combination using the genotyping method of matrix assisted laser desorption/ionization time of flight mass spectrometry(MALDI-TOF-MS).The selected SNP markers were then genotyped for each F_1 individuals using high resolution m elting(HRM) technology.The genotype for F_1 hybrids could be divided into three groups:heterozygous genotype,homozygous genotype as female cultivar and homozygous genotype as male cultivar.For each three cross combination,all the F_1 hybrids were successfully identified by only one homozygous codominant SNP marker.True hybrid ratio for‘Baitangying'בHexiachuan',‘Hexiachuan'בBaitangying'and‘Baitangying'בWuheli'were 93.6%、96.8% and 72.5%,respectively.SNP markers were successfully applied to identification of F_1 hybrid of three litchi cross combinations for the first time,which would provide a reference means for authenticity identification in litchi cross breeding in the future.