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）三个地区的68个重要橄榄栽培品种，开展形态与遗传多样性综合评估。研究共测定25项表型性状，并对12个简单序列重复（Simple Sequence Repeat, SSR）标记进行分析。所有SSR引物均具备多态性且稳定性优异。每个位点的等位基因总数介于5至19之间，均值为13.1，平均多态性信息含量（Polymorphic Information Content, PIC）达0.81。上述结果表明，这三个橄榄种质资源库内存在较高水平的遗传多样性。表型性状在各栽培品种间亦表现出显著变异。通过基于SSR的亲权模拟分析并结合CERVUS软件，本研究共鉴定出2个品种遗传同一性案例，以及10个具有统计学显著性的推定亲本/姊妹系案例。曼特尔检验（Mantel test）结果显示，表型数据与SSR等位基因频率、起源地与SSR等位基因频率、起源地与表型性状之间均存在低度但显著的相关性。Structure软件可用于推断三个橄榄种质资源库间的亲缘关系，助力我们获得一致性最高的群体划分结果，并鉴定出推定的混合起源或种质交流品种。基于表型性状的聚类与多变量分析结果显示，其地理分组模式与基于SSR的未加权算术平均聚类法（UPGMA）聚类树及Structure软件分析结果一致。西西里岛的橄榄栽培品种具有更为均一的遗传组成，这大概率源于地理隔离；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，种质间的混杂程度更高。本研究还发现，部分SSR等位基因的存在与果实大小存在显著相关性。