大麻植物中大麻素含量QTL定位研究

The main cannabinoids in the plant of cannabis sativa L. are cannabidiol (CBD) and tetrahydrocannabinol (THC, an ingredient with hallucinogenic addiction), which are attracting more and more attention for their high medicinal value nowadays. However, the genetic basis of difference in cannabinoid content is not clear , which results in lacking of effective means to select cannbinoid content in breeding. In our previous work, cannabinoid content was revealed to be quanititatively inherited with the major gene and polygenes. In this research, two inbred strains of medical cannabis with high cannabinoid content and fiber cannabis with low cannabinoid content are chosen as parents to construct pure-female F2 segregation population. Then multi-field tests on F2 offsprings would be carried out by asexual reproduction, to analyze the correlation between cannabinoid content and plant height, internode length or growth period. And high density genetic map will be constructed based on SNP marker developed by specific-locus amplified fragment sequencing (SLAF-seq), combined with SSR and CAPS markers designed with key genes in cannabinoid biosynthesis pathway. After that, QTLs for cannabinoid content would be mapped. Finally, near-isogenic line (NIL) of cannabinoid content will be developed through backcrossing with marker-assisted selection. This research will lay foundation for marker-assisted selection of cannabinoid content and cloning of related genes.

大麻植物中大麻素主要成分为大麻二酚（CBD）和四氢大麻酚（THC），因二者均具有极高的药用价值（THC兼有致幻成瘾性）而备受关注。由于大麻素含量差异形成的遗传基础不清楚，育种过程中难以针对大麻素含量进行有效选择。项目组前期工作表明大麻素含量为主效基因控制的数量性状，本研究拟用药用大麻近交系（高大麻素含量）和纤用大麻近交系（低大麻素含量）为亲本构建全雌性的F2群体，并无性繁殖F2进行多点试验，开展大麻素含量与株高、节间长、生育期等重要性状之间的相关性分析；采用基于特异位点扩增片段高通量测序技术（SLAF-seq）开发的SNP标记和基于大麻素合成途径关键基因开发的SSR、CAPS标记，联合构建大麻高密度遗传图谱，对大麻素含量的QTL进行定位；使用主效QTL连锁标记辅助选择开展多代回交，培育大麻素含量主效QTL近等基因系（NIL）。研究结果为大麻素含量分子标记辅助选择和相关基因克隆奠定基础。

大麻素是大麻植物中特有的一类次生代谢产物，主要成分是大麻二酚（CBD）和四氢大麻酚（THC），二者均具有重要的药用价值（THC兼有致幻成瘾性）而备受关注。鉴于大麻素含量差异形成的遗传基础不清楚，本项目拟通过开展大麻素含量QTL定位，来推进大麻素分子辅助育种。通过项目实施：（1）构建了大麻高密度遗传图谱，图谱含24852个SNP和InDel标记，平均图距0.061cM；（2）建立了大麻素HPLC检测技术体系，得出大麻素总含量同时受到基因型和环境的极显著影响，广义遗传力为0.67；（3）在3种不同环境下，大麻素总含量同CBDA含量成极显著正相关，同株高和小叶宽成显著或极显著负相关，并定位了4个大麻素总含量相关QTL，分别位于1号（1个）、2号（1个）和5号（2个）染色体上，其中1号染色体qR.TC.1-1位点筛选了4个可能影响大麻素总含量的候选基因，分别为evm.TU.01.992、evm.TU.01.1030、evm.TU.01.1034和evm.TU.01.1062；（4）开发了大麻素总含量连锁的InDel分子标记1对，构建了BC2F1回交材料；（5）获得了一批高CBD、低THC的F2株系材料。研究结果为大麻素含量等农艺性状的分子标记辅助育种、精细定位及基因克隆奠定了基础，创制的材料将在CBD高含量工业大麻品种选育工作中迅速得以应用。发表论文8篇（含SCI 2篇），获发明专利授权1项，选育新品种1个，培养硕士研究生2人，项目负责人期间入选了云南省中青年学术和技术带头人后备人才和云南省万人计划“青年拔尖”人才计划。