School of Landscape and Architecture, Zhejiang A&F University, 666# Wusu Road, Lin'an, 311300, Zhejiang, China.
Nurturing Station for the State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, 666# Wusu Road, Lin'an, 311300, Zhejiang, China.
Mol Genet Genomics. 2019 Feb;294(1):135-147. doi: 10.1007/s00438-018-1493-7. Epub 2018 Sep 25.
Magnolia sinostellata is an endemic species of Magnoliaceae that is narrowly distributed in the south of Zhejiang Province, China. To explore the genetic diversity and population structure of this endangered species, this study developed sequence tag-simple sequence repeat (EST-SSR) markers based on transcriptome data of M. sinostellata. In total, 25472 SSRs were identified among 110644 unique assembled sequences with a total of 90.83 Mb and an average frequency of 23.02%. The mononucleotide (33.53%) and dinucleotide (42.08%) motifs appeared to be the most abundant. In total, 150 potential loci were randomly selected to validate the quality of the developed SSR markers; an effective PCR rate of 32.00% and a polymorphism rate of 15.33% were obtained for these loci. After performing sequencing and cloning for validation, 23 pairs of SSR primers were retained and used to characterize the genetic diversity and population structure of M. sinostellata. Overall, 204 alleles were amplified. The results of Shannon's information index (I), heterozygosity (Ho), heterozygosity (He) and Nei's expected heterozygosity (H) indicated rich genetic diversity in M. sinostellata. However, the high inbreeding coefficient and differential coefficient suggest that serious genetic drift occurred within populations, and genetic differentiation is apparent among the populations. Consequently, although M. sinostellata has high genetic diversity among populations, it is still in a serious and dangerous condition. Habitat destruction caused by human activities is the main threat to this species, and enhancing the species abundance by adopting some conservation measures should be favourable for saving the species.
乐昌含笑是木兰科含笑属的一个分布狭窄的中国特有种，分布于中国浙江省南部。为了探究这个濒危物种的遗传多样性和种群结构，本研究基于乐昌含笑转录组数据开发了序列标签简单重复（EST-SSR）标记。在总共 110644 条独特组装序列中，共鉴定出 25472 个 SSR，总长 90.83Mb，平均频率为 23.02%。单核苷酸（33.53%）和二核苷酸（42.08%）基序似乎是最丰富的。总共随机选择了 150 个潜在的位点来验证开发的 SSR 标记的质量；这些位点的有效 PCR 率为 32.00%，多态性率为 15.33%。经过测序和克隆验证，保留了 23 对 SSR 引物，并用于表征乐昌含笑的遗传多样性和种群结构。总共扩增了 204 个等位基因。Shannon 信息指数（I）、杂合度（Ho）、期望杂合度（He）和 Nei 预期杂合度（H）的结果表明乐昌含笑具有丰富的遗传多样性。然而，高近交系数和差异系数表明种群内发生了严重的遗传漂变，种群间存在明显的遗传分化。因此，尽管乐昌含笑在种群间具有较高的遗传多样性，但它仍处于严重和危险的状态。人类活动导致的栖息地破坏是该物种的主要威胁，通过采取一些保护措施来增加物种丰度，有利于拯救该物种。
