利用荧光SSR标记分析中国油橄榄品种遗传多样性

Genetic Diversity of Olive Cultivars in China Based on Fluorescent SSR Markers

为研究我国53个油橄榄品种(13个引种驯化选育品种和40个引种品种)的遗传变异,利用SSR荧光标记技术对从甘肃的陇南、四川的西昌、广元和云南的永仁5个地点收集的107份材料进行遗传多样性分析。20对引物共检测出294个等位变异,每对引物的等位基因数在9～26之间,平均为14.7个;多态性信息量PIC值平均为0.73(0.33～0.89)。基于Jaccard系数的NJ法聚类分析结果表明,参试材料分为2大组,选育品种与引种品种未被分开,但大多数具有相同品种名称的材料被分在同一组中,无论是选育品种还是引种品种均具有高水平遗传多样性。对来自5个国家的油橄榄品种群体进行分子方差分析(AMOVA)结果表明,品种内遗传变异(86.61%)远远超过了群体间和群体内不同品种间的遗传变异(13.39%),大规模引种过程中对品种的起源和来源地等信息并不完全,以及在长期引种栽培和苗木繁育过程中品种混淆和同名异种等,都是造成品种内遗传变异水平高的原因。

To study the genetic variation of 53 olive(Olea europaea) cultivars in China,107 accessions of 13 domesticated cultivars and 40 imported cultivars were collected from 5 sites of olive culture regions in three provinces of China(Gansu,Sichuan and Yunnan) and analyzed using 20 fluorescent polymorphic simple sequence repeats(SSRs).Twenty SSR primers amplified 294 polymorphic alleles in the 107 selected olive accessions.The average number of alleles per locus was 14.7,ranging from 9 to 26.Polymorphic information content(PIC) was 0.73 on average.The genetic relationships among accessions were investigated using cluster analysis based on NJ with Jaccard coefficient.The 107 accessions from different regions were separated into two groups.Although there was no clear separation between domesticated and imported cultivars,most of the accessions with the same cultivar name were grouped together.As expected,close relationship was observed among accessions within the same cultivar.The analysis revealed the high level genetic diversity within these cultivars,regardless of selected domestic cultivars and introduced cultivars from foreign country.Between and within cultivars(cultivars including three or more accessions) originated from 5 different countries genetic diversity was analyzed using analysis of molecular variance(AMOVA).AMOVA revealed that genetic variation within cultivar was higher(86.61%) than that between populations and between cultivars among populations(13.39%).The high level of genetic variance within cultivar could be due to 1) inaccurate information related to origin and source of cultivars during long-term and large-scale introduction and 2) mislabeling and presence of homonyms in cultivars produced by vegetative propagation from original plants.