Institute of Bast Fiber Crops, Chinese Academy of Agricultural Sciences, Changsha, 410205, China.
Key Laboratory of the Biology and Process of Bast Fiber Crops, Ministry of Agriculture, Changsha, China.
BMC Genomics. 2021 Aug 5;22(1):595. doi: 10.1186/s12864-021-07883-w.
Cannabis sativa L., a dioecious plant derived from China, demonstrates important medicinal properties and economic value worldwide. Cannabis properties have been usually harnessed depending on the sex of the plant. To analyse the genetic structure of Chinese Cannabis and identify sex-linked makers, genome-wide insertion-deletion (InDel) markers were designed and used.
In this study, a genome-wide analysis of insertion-deletion (InDel) polymorphisms was performed based on the recent genome sequences. In total, 47,558 InDels were detected between the two varieties, and the length of InDels ranged from 4 bp to 87 bp. The most common InDels were tetranucleotides, followed by pentanucleotides. Chromosome 5 exhibited the highest number of InDels among the Cannabis chromosomes, while chromosome 10 exhibited the lowest number. Additionally, 31,802 non-redundant InDel markers were designed, and 84 primers evenly distributed in the Cannabis genome were chosen for polymorphism analysis. A total of 38 primers exhibited polymorphisms among three accessions, and of the polymorphism primers, 14 biallelic primers were further used to analyse the genetic structure. A total of 39 fragments were detected, and the PIC value ranged from 0.1209 to 0.6351. According to the InDel markers and the flowering time, the 115 Chinese germplasms were divided into two subgroups, mainly composed of cultivars obtained from the northernmost and southernmost regions, respectively. Additional two markers, "Cs-I1-10" and "Cs-I1-15", were found to amplify two bands (398 bp and 251 bp; 293 bp and 141 bp) in the male plants, while 389-bp or 293-bp bands were amplified in female plants. Using the two markers, the feminized and dioecious varieties could also be distinguished.
Based on the findings obtained herein, we believe that this study will facilitate the genetic improvement and germplasm conservation of Cannabis in China, and the sex-linked InDel markers will provide accurate sex identification strategies for Cannabis breeding and production.
大麻（Cannabis sativa L.），一种源自中国的雌雄异株植物，在全球范围内具有重要的药用特性和经济价值。大麻的特性通常取决于植物的性别。为了分析中国大麻的遗传结构并鉴定性连锁标记，设计并使用了全基因组插入-缺失（InDel）标记。
本研究基于最近的基因组序列对插入-缺失（InDel）多态性进行了全基因组分析。在两个品种之间共检测到 47558 个 InDel，InDel 的长度范围从 4bp 到 87bp。最常见的 InDel 是四核苷酸，其次是五核苷酸。大麻染色体中，5 号染色体的 InDel 数量最多，而 10 号染色体的 InDel 数量最少。此外，设计了 31802 个非冗余 InDel 标记，并选择了 84 个均匀分布在大麻基因组中的引物用于多态性分析。在三个品种中，共检测到 38 个引物表现出多态性，其中 14 个双等位基因引物进一步用于遗传结构分析。共检测到 39 个片段，PIC 值范围为 0.1209 到 0.6351。根据 InDel 标记和开花时间，115 个中国种质资源被分为两个亚组，主要由来自最北部和最南部地区的品种组成。另外两个标记“Cs-I1-10”和“Cs-I1-15”在雄性植物中扩增出两条带（398bp 和 251bp；293bp 和 141bp），而在雌性植物中扩增出 389bp 或 293bp 带。使用这两个标记，还可以区分雌性和雌雄异株品种。
基于本研究的结果，我们相信这将促进中国大麻的遗传改良和种质资源保护，性连锁 InDel 标记将为大麻的育种和生产提供准确的性别鉴定策略。
