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草业学报 ›› 2025, Vol. 34 ›› Issue (7): 107-119.DOI: 10.11686/cyxb2024304

• 研究论文 • 上一篇    

扇穗茅全长转录组SSR特征分析及分子标记开发

富贵1,2,4(), 刘玉萍3,4,5, 苏旭3,4,5(), 曲荣举3, 才让扎西3   

  1. 1.青海师范大学地理科学学院,青海 西宁 810008
    2.青海民族大学生态环境与资源学院,青海 西宁 810007
    3.青海师范大学生命科学学院,青海 西宁 810016
    4.青海师范大学青海省青藏高原生物多样性形成机制与综合利用重点实验室,青海 西宁 810008
    5.青海师范大学高原科学与可持续发展研究院,青海 西宁 810016
  • 收稿日期:2024-07-31 修回日期:2024-09-12 出版日期:2025-07-20 发布日期:2025-05-12
  • 通讯作者: 苏旭
  • 作者简介:E-mail: xusu8527972@126.com
    富贵(1987-),男,甘肃天水人,副教授,在读博士。E-mail: qhmdfg@163.com
  • 基金资助:
    2023年中央林业草原生态保护恢复资金野生动植物保护项目,青海野生单子叶植物种质资源调查及其多样性评价项目(QHSY-2023-016);青海民族大学2024年大学生创新创业训练计划项目(2024-DCXM-55)

Analysis of SSR characterization in full-length transcriptome and development of SSR molecular markers for Littledalea racemosa

Gui FU1,2,4(), Yu-ping LIU3,4,5, Xu SU3,4,5(), Rong-ju QU3, Zha-xi CAIRANG3   

  1. 1.School of Geosciences,Qinghai Normal University,Xining 810008,China
    2.College of Ecological Environmental and Resources,Qinghai Minzu University,Xining 810007,China
    3.School of Life Sciences,Qinghai Normal University,Xining 810016,China
    4.Key Laboratory of Biodiversity Formation Mechanism and Comprehensive Utilization of the Qinghai-Tibet Plateau in Qinghai Province,Qinghai Normal University,Xining 810008,China
    5.Academy of Plateau Science and Sustainability,Qinghai Normal University,Xining 810016,China
  • Received:2024-07-31 Revised:2024-09-12 Online:2025-07-20 Published:2025-05-12
  • Contact: Xu SU

摘要:

扇穗茅是青藏高原特有的一种具有重要生态和经济价值的禾本科草本植物,开发稳定高效的微卫星(SSR)分子标记可为其遗传多样性、系统发育和物种分布格局等研究提供重要的技术手段。本研究基于Pacbio测序平台获得扇穗茅全长转录组30624条Unigene序列,利用MISA软件搜索到14089个SSR重复序列,SSR发生频率为33.85%;通过对SSR位点特征分析发现,SSR位点包含6种核苷酸重复类型,其中单、二、三核苷酸占所有核苷酸类型的97.35%,为主要重复类型;3种主导基序类型中,三核苷酸所形成的基元类型数目最多,共检测到10个基元类型,其中CCG/CGG基元类型占优,共形成1736个SSR位点,占三核苷酸总SSR位点的31.32%;随机挑选12个不同居群的扇穗茅样本对合成的160对引物进行PCR扩增和琼脂糖凝胶电泳检测,最终获得扩增稳定、具特异性的15对SSR引物。基于扇穗茅27个居群、81个个体,对15对SSR引物多态性进行了分析,共扩增出132个观测等位基因,平均每对引物扩增出8.8个观测等位基因,有效等位基因数(Ne)、Shannon’s信息指数(I)、多态性信息含量(PIC)、观测杂合度(Ho)、期望杂合度(He)平均值分别为4.7799、1.6959、0.7270、0.8575和0.7648。基于Nei’s遗传距离利用UPGMA方法进行聚类分析,结果表明,扇穗茅居群间和居群内个体间存在明显的系统亲缘关系,不同居群间遗传距离可能和地理距离相关。本研究开发的15对SSR引物遗传多样性丰富,可为扇穗茅种质资源遗传变异研究提供更加有效的标记选择。

关键词: 扇穗茅, 转录组, SSR, 分子标记

Abstract:

Littledalea racemosa is a herb with significant ecological and economic value belonging to the Poaceae family and endemic to Qinghai-Xizang Plateau. Identification of a suitable set of simple sequence repeat (SSR) molecular markers offers an important technical means for studying genetic diversity, phylogenetics, and species distribution patterns. In this study, 14089 SSR sequences were obtained using MISA software from 30624 Unigene sequences derived from the L. racemosa full-length transcriptome with the Pacbio sequencing platform. The value of incidence of SSR was 33.85%. Analysis of SSR characteristics, indicated six types of SSR locus nucleotide repeats, with mono-nucleotide, di-nucleotide, and tri-nucleotide being the dominant repeat motifs and accounting for 97.35% of all nucleotide types. Among these three dominant motif types, tri-nucleotide SSRs were the most frequently encountered, with a total of 10 detected. The CCG/CGG motif type was most common and occurred at a total of 1736 SSR sites, accounting for 31.32% of the total SSR tri-nucleotide sites. Twelve samples of L. racemosa were selected randomly from different populations and used by PCR amplification and agarose gel electrophoresis examination for 160 pairs of primers, and 15 pairs of SSR primers with stable amplification and specificity were finally obtained. For these 15 pairs of SSR primers, polymorphism of 81 individuals from 27 populations was analyzed, and a total of 132 alleles could be amplified, with an average of 8.8 alleles amplified per primer pair. The effective allele number (Ne), Shannon information index (I), polymorphic information content (PIC), observed heterozygosity (Ho), and expected heterozygosity (He), were 4.7799, 1.6959, 0.7270, 0.8575, and 0.7648, respectively. Cluster analysis was conducted using the UPGMA method based on Nei’s genetics distance, and the results showed that there were explicit genetic relationships among the populations and individuals within a population of L. racemosa. The genetic distance between different populations may be related to geographical distance. The 15 pairs of SSR primers developed in this study have rich genetic diversity, which can provide effective marker selection for genetic variation research in germplasm resourcesof L. racemosa.

Key words: Littledalea racemosa, transcriptome, SSR, molecular marker