火龙果主要商业品种SSR指纹图谱构建和遗传多样性分析

为了准确鉴定火龙果主要商业品种和评估其遗传多样性,本研究利用20对火龙果SSR核心引物对58个火龙果品种进行遗传多样性分析,采用毛细管电泳技术进行多态性位点检测,共检测到116个多态位点,平均每个位点等位基因数（Na）为5.8个,有效等位基因数（Ne）为2.0519,观测杂合度（Ho）为0.3318,期望杂合度（He）为0.4603,多态性信息含量指数（PIC）为0.417。基于遗传相似系数聚类结果,将火龙果主要商业品种分为3大类群。依据20对SSR引物在58个品种中扩增的特异带型组合,选取其中9对引物采用引物-带型组合法构建了58个火龙果品种的指纹图谱,品种鉴定的置信概率几乎为100%。研究结果可为火龙果种质分类、品种鉴定和品种权保护提供重要的理论依据与技术支撑。

Genetic Diversity Analysis and SSR Fingerprint Construction of Pitaya Cultivars

In order to accurately identify pitaya cultivars and evaluate their genetic diversity, 20 pairs of SSR core primers were used to analyze the genetic diversity of 58 pitaya varieties, and polymorphic alleles were detected by capillary electrophoresis. Totally, 116 polymorphic alleles were revealed, with an average of 5.8 for each primer pairs. The average number of alleles (Na), number of effective alleles (Ne), observed heterozygosity (Ho), expected heterozygosity (He), and polymorphism information content (PIC) was 5.8, 2.0519, 0.3318, 0.4603 and 0.417, respectively. Based on the clustering results of genetic similarity coefficient, the main commercial cultivars of pitaya were divided into three groups. Based on 20 pairs of SSR primers amplified from 58 cultivars, the fingerprints of 58 cultivars of pitaya were constructed using 9 pairs of primers. A strategy of combining primer pair with distinct alleles for fingerprint construction was developed and applied to the 58 cultivars. The confidence probability of variety identification was almost 100%. The research results would provide important theoretical basis and technical support for the germplasm classification, cultivar identification and varieties property protection of pitaya.