Li Zihang, He Lifei, Wang Xiujun, Guo Linfan, Luo Chunyan, Li Qingwei
School of Landscape Architecture, Beijing Forestry University, Beijing 100083, China.
Beijing Florascape Co., Ltd., Beijing 100032, China.
Sheng Wu Gong Cheng Xue Bao. 2023 Jul 25;39(7):2839-2860. doi: 10.13345/j.cjb.220913.
The present study aims to explore the genetic diversity of germplasm resources of × (hereinafter, ×) at the molecular level and to establish a fingerprint database of × varieties. We employed 12 pairs of primers with high levels of polymorphism, clear bands, and high degrees of reproducibility to analyze the SSR molecular markers and genetic diversity of 91 × materials and 14 chrysanthemum- related materials. With regard to constructing the fingerprints of the tested materials, we chose 9 pairs of core primers. The findings revealed that 12 primer pairs detected 104 alleles in 105 samples, ranging from 2 to 26. The average number of observed alleles () per site was 9.25. The average number of effective alleles () per site was 2.745 6, with its range being 1.276 0 to 4.742 5. Shannon genetic diversity index () values ranged between 0.513 3 and 2.239 9 (=1.209 0). Nei's gene diversity index () ranged between 0.216 3 and 0.789 1 (=0.578 0). The observed heterozygosity () ranged between 0.223 3 and 0.895 2 (=0.557 5). The expected heterozygosity () ranged between 0.217 4 and 0.793 3 (=0.580 8). The polymorphism information content (PIC) ranged between 0.211 5 and 0.774 0 (=0.532 9). The genetic similarity (GS) ranged between 0.228 5 and 1.000 0 (=0.608 3). Cluster analysis revealed that when the genetic distance (GD) equals to 0.30, the tested materials can be classified into 2 groups. When the GD equals to 0.27, the first group can be divided into 6 subgroups; accordingly, 105 tested materials can be divided into 7 subgroups. The cophenetic correlation test was carried out based on the cluster analysis, and the corresponding results showed that the cluster map correlated with the genetic similarity coefficient (r=0.952 73). According to the results of Structure population analysis, we obtained the optimal population number, with the true number of populations (K) being 3 and the population being divided concerning Q≥0.5. Three subgroups, i.e., Q1, Q2 and Q3, included 34, 33 and 28 germplasms, respectively, and the remaining 10 germplasms were identified as the mixed population. During the experiment, 9 pairs of core primers were screened among the total of 12 for a complete differentiation regarding 105 tested materials, and the fingerprints of 91 × materials and 14 chrysanthemum-related materials were further constructed. Overall, there were significant genetic differences and rich genetic diversity among × materials, which would shed light on the garden application and variety selection fields of ×. The fingerprint database of 105 × varieties and chrysanthemum-related species may provide technical support for future research regarding the identification and screening system of × varieties.
本研究旨在从分子水平探索×（以下简称×）种质资源的遗传多样性，并建立×品种的指纹图谱数据库。我们采用12对多态性高、条带清晰且重复性高的引物，对91份×材料和14份菊花相关材料进行SSR分子标记及遗传多样性分析。在构建供试材料指纹图谱方面，我们选择了9对核心引物。结果显示，12对引物在105个样本中检测到104个等位基因，范围为2至26个。每个位点观察到的等位基因平均数量（）为9.25个。每个位点的有效等位基因平均数量（）为2.745 6，范围为1.276 0至4.742 5。香农遗传多样性指数（）值在0.513 3至2.239 9之间（=1.209 0）。内氏基因多样性指数（）在0.216 3至0.789 1之间（=0.578 0）。观察到的杂合度（）在0.223 3至0.895 2之间（=0.557 5）。期望杂合度（）在0.217 4至0.793 3之间（=0.580 8）。多态性信息含量（PIC）在0.211 5至0.774 0之间（=0.532 9）。遗传相似性（GS）在0.228 5至1.000 0之间（=0.608 3）。聚类分析表明，当遗传距离（GD）等于0.30时，供试材料可分为2组。当GD等于0.27时，第一组可分为6个亚组；相应地，105份供试材料可分为7个亚组。基于聚类分析进行了共表型相关检验，相应结果表明聚类图与遗传相似系数相关（r = 0.952 73）。根据结构群体分析结果，我们获得了最优群体数，真实群体数（K）为3，群体划分依据Q≥0.5。三个亚组，即Q1、Q2和Q3，分别包含34、33和28份种质，其余10份种质被鉴定为混合群体。实验过程中，从12对引物中筛选出9对核心引物，以实现对105份供试材料的完全区分，并进一步构建了91份×材料和14份菊花相关材料的指纹图谱。总体而言，×材料之间存在显著的遗传差异和丰富的遗传多样性，这将为×的园林应用和品种选择领域提供参考。105份×品种及菊花相关物种的指纹图谱数据库可为未来×品种鉴定和筛选系统的研究提供技术支持。
