Key Comprehensive Laboratory of Forest for Shaanxi Province, College of Forestry, Northwest A&F University, Yangling, Shannxi, China.
Germplasm Repository of Tropical Fruits, South Subtropical Crops Research Institute, Chinese Academy of Tropical Agricultural Science, Zhanjiang, Guangdong, China.
Planta. 2019 Jun;249(6):1875-1887. doi: 10.1007/s00425-019-03133-2. Epub 2019 Mar 12.
A set of reliable SSR markers were developed for Ziziphus mauritiana. The genetic relationship of Z. mauritiana germplasms was generally consistent with their geographical origin, and low diversity in the maternal lineage was revealed. Ziziphus mauritiana, known as Indian jujube, is an important fruit crop that is native to southern Asia and eastern Africa. There is a variety of germplasm resources, and particularly many new cultivars were selected and introduced into wide tropical regions in recent years. However, there are few practical molecular markers for cultivar authentication and genetic analysis. In this study, we developed 55 polymorphic nuclear SSR markers based on restriction-site associated DNA sequences and transcriptome sequencing. We selected 14 robust nSSR markers for further analysis of 117 Z. mauritiana accessions from four countries (45 from China, 39 from Vietnam, 25 from Pakistan and 8 from Myanmar). In total, 137 alleles were detected and DNA fingerprints for each accession were constructed. Cluster analysis based on the unweighted pair group method with arithmetic mean displayed that most accessions clustered consistently with their geographic origin. In addition, there was common and high degree polyploidization based on nSSR and flow cytometry analyses. Only two of the 50 SSR loci in noncoding regions from the chloroplast genome had polymorphisms, and 5 haplotypes in total were identified among the 117 accessions. Haplotype C with 89 accessions was the most dominant haplotype and presented in four countries. This indicates low diversity in the maternal lineage of tested Z. mauritiana germplasm. Our research provides reliable marker resources for cultivar authentication and new insights into the genetic diversity, polyploidization and domestication of Z. mauritiana.
一组可靠的 SSR 标记被开发用于毛叶枣。毛叶枣种质的遗传关系通常与其地理起源一致，揭示了母系的低多样性。毛叶枣，又称印度枣，是一种重要的水果作物，原产于南亚和东非。它有各种各样的种质资源，特别是近年来许多新的品种被选育并引入到广泛的热带地区。然而，用于品种鉴定和遗传分析的实用分子标记却很少。在这项研究中，我们基于限制性相关 DNA 序列和转录组测序开发了 55 个多态性核 SSR 标记。我们选择了 14 个稳健的 nSSR 标记，进一步分析了来自四个国家的 117 个毛叶枣品种（中国 45 个，越南 39 个，巴基斯坦 25 个，缅甸 8 个）。共检测到 137 个等位基因，并构建了每个品种的 DNA 指纹图谱。基于算术平均值的未加权对组平均法的聚类分析显示，大多数品种与其地理起源一致聚类。此外，基于 nSSR 和流式细胞术分析，存在常见且高度的多倍化。叶绿体基因组中非编码区的 50 个 SSR 位点中只有 2 个具有多态性，在 117 个品种中总共鉴定出 5 个单倍型。具有 89 个品种的单倍型 C 是最优势单倍型，在四个国家均有出现。这表明测试的毛叶枣种质的母系多样性较低。我们的研究为品种鉴定提供了可靠的标记资源，并为毛叶枣的遗传多样性、多倍化和驯化提供了新的见解。
