利用SRAP和SCoT两种分子标记相结合对中国22个番木瓜主要栽培品种(系)进行遗传多样性研究。SCoT标记检测获得的遗传多样性参数值和遗传相似系数范围均高于SRAP标记检测的结果,表明SCoT标记检测多态性的能力高于SRAP标记。基于两种标记数据合并后的UPGMA聚类结果显示,番木瓜种质间的遗传相似系数为0.65~0.90,种质间遗传多样性水平较低;在相似性系数为0.82时,将所有参试材料划分为3个类群。应用Mantel检测对SRAP和SCoT及两种标记合并进行相关性分析,表明三者之间具有显著的相关性,且相关性很高。聚类结果从分子水平反映出中国番木瓜主要栽培品种(系)的遗传基础狭窄。
Sequence-related amplified polymorphism (SRAP) and start condon targeted polymorphism (SCoT) molecular markers were used to detect the genetic diversity among 22 main cultivars (strains) of papaya (Carica papaya L.) in China. Genetic diversity parameters and the range of genetic similarity (GS) from SCoT were all higher than those from SRAP indicating the genetic diversity identified by SCoT was higher than that by SRAP. UPGMA cluster analysis based on combination of two molecular markers data showed that the range of GS was 0.65–0.90 among 22 papaya resources with a low genetic diversity, and all resources could be divided into three groups at the GS of 0.82. The data implied a correlation among SRAP, SCoT and these markers combination, which showed a significant relationship using Mantel test. These results indicated that the genetic basis of papaya resources in China is narrow.