高油酸花生品种(系)ahFAD基因变异鉴定及遗传多样性分析

ahFAD Genotype Identification and Genetic Diversity Analysis of High Oleic Acid Peanut Cultivars

为研究不同亲本来源高油酸品种(系)的遗传差异,选用来源于5个高油酸供体亲本的25个品种(系)进行分析。所选材料油酸含量均大于75%,油酸亚油酸比值大于10。对控制油酸基因ahFAD进行分析,结果表明,所选高油酸品种(系)的ahFAD2A与ahFAD2B均未发生突变,ahFAD2A为G448A的替换,ahFAD2B为442 A的插入。698对SSR引物对25个品种(系)进行检测,140对引物在品种间检测到差异;共检测到379个等位变异,遗传多态性指数的变化范围为0.074~0.728,平均0.371;筛选到17个多态性丰富,扩增产物稳定的引物,可用于25个品种(系)进行鉴定区分。遗传距离分析表明,25个品种遗传距离在0.057~0.624之间,平均为0.451。对高油酸品种(系)进行聚类分析,在遗传相似性系数0.745处,被分为11个类群,类群分布与亲本来源具有一致性,可实现对一些资源或育成品种进行亲本类型的推测,并为花生分子标记辅助育种提供参考。

To study the genetic difference of the high oleic acid peanut cultivars,twenty-five offspring varieties from five high oleic acid parents were investigated by using gene-based and genetic marker-based diversity analysis approaches.The oleic acid content and O/L of 25 peanut varieties were higher than 75%and 10,respectively.By analyzing the full-length sequence of ahFAD genes of these varieties,a nucleotide substitution of G448A was found in FAD2A,while a nucleotide insertion of A at 442 from the translation starting code in FAD2B was identified.Searching for polymorphism in 25 varieties using 698 SSR markers,140 SSR markers were found to be polymorphic,which produced a total of 379 alleles.The genetic diversity index value ranged from 0.074 to 0.728 with average of 0.371.Notably,these 25 varieties were distinguishable by using 17 polymorphic SSR markers.The genetic distance ranged from 0.057 to 0.624 with a mean value of 0.451.Eleven groups were revealed when the genetic similar coefficients of 0.745 which was able to distinguish the parents and the offspring varieties.Taken together,the results may become useful in the pedigree analysis of the high oleic acid peanut varieties and the molecular marker assisted selection in peanut breeding.