Data from: Genetic relationships, structure and parentage simulation among the olive tree (Olea europaea L. subsp. europaea) cultivated in Southern Italy revealed by SSR markers

In this work, we assess both the morphological and genetic diversity of 68 important olive cultivars from three Southern Italian regions: Calabria, Campania and Sicily. Twenty-five phenotypic traits were evaluated and 12 simple sequence repeat (SSR) markers were analysed. All SSR primers were polymorphic and reliable. The total number of alleles per locus varied from 5 to 19 with an average number of 13.1 and a mean polymorphic information content (PIC) of 0.81. These results suggested high genetic diversity within these three olive germplasm collections. Morphological traits also showed significant variability amongst cultivars. Two cases of identity were found and ten statistically significant cases of putative parent/sibling were discovered by performing a SSR-based parentage simulation analysis with CERVUS. The Mantel test indicated low but significant correlations between the morphological data and SSR allelic frequency, origin and SSR allelic frequency, and origin and morphology. Structure software allowed inference of relationships between the three olive germplasm collections and allowed us to obtain the most consistent grouping and to identify putative admixed or exchanged cultivars. Cluster and multivariate analysis, based on morphological traits, revealed geographic grouping in agreement with UPGMA dendrogram and structure analysis using SSRs. Sicilian cultivars showed a more homogenous genetic makeup, probably due to geographical isolation, whilst Calabrian and Campanian cultivars seemed to have a less distinct genetic structure, with a greater degree of intermixing. A correlation between the presence of certain SSR alleles and fruit size was also found.

本研究针对意大利南部卡拉布里亚（Calabria）、坎帕尼亚（Campania）与西西里（Sicily）三个大区的68个重要油橄榄栽培品种，系统评估了其形态学与遗传多样性。本研究共测定25项表型性状，并分析了12个简单序列重复（simple sequence repeat, SSR）分子标记。所有SSR引物均具备多态性且稳定性良好：每个位点的等位基因总数介于5至19之间，平均等位基因数为13.1，平均多态性信息含量（polymorphic information content, PIC）为0.81。上述结果表明，该三个油橄榄种质资源集合内部存在较高的遗传多样性。表型性状在不同栽培品种间亦呈现出显著变异。借助基于SSR的亲权模拟分析软件CERVUS，本研究共检出2例遗传同一性样本，同时发现10例具有统计学显著性的疑似亲本或同胞关系案例。曼特尔检验（Mantel test）结果显示，表型数据与SSR等位基因频率、地理起源与SSR等位基因频率，以及地理起源与表型性状之间均存在虽微弱但具有统计学意义的相关性。Structure软件可用于推断该三个油橄榄种质资源集合间的亲缘关系，帮助我们获得最具一致性的类群划分结果，并鉴定出疑似存在遗传渐渗或种质交换的栽培品种。基于表型性状的聚类与多变量分析结果显示，其地理分布分组与基于SSR的非加权组平均法（UPGMA）聚类树及Structure群体结构分析结果一致。西西里岛的油橄榄栽培品种具有更为均一的遗传组成，这可能源于地理隔离；而卡拉布里亚与坎帕尼亚的栽培品种遗传结构则相对模糊，种质间的基因交流程度更高。本研究还发现，部分SSR等位基因的存在与果实大小存在相关性。