胡椒种质资源遗传多样性与分子身份证研究

Current abundant black pepper (Piper nigrum) germplasms are derived from long process of nature evolution, genetic mutation, selection breeding, etc. Many of its germplasms have very similar morphology characters, and to distinguish and identify them have been difficult by conventional classification approaches. Meanwhile, management omissions in the process of its germplasm introductions and production managements have lead to existing confusions in the germplasm naming system and ambiguities of their heredity bases, which are greatly hindering their further exploration, sharing and utilization. In current project, the experimental system of "SSR markers+DNA fragment sequencing" would be used to establish the molecular ID and DNA barcoding for P. nigrum germplasms aiming to solve some problems, such as synonym, homonym and confuable varieties. Meanwhile, phylogenetic tree would also be built to reveal the genetic relationship, identify genetics base, and address some taxonomic questions of its germplasms. This project can provide technical supports for identification and classification of P. nigrum germplasms, authenticity and purity of its varieties as well as intellectual property protection and promoting. Current project holds profound meanings to many aspects of the future genetic improvement, breeding parent selection, germplasm conservation and establishment of its core breeding germplasms repository system.

长期自然演化、突变、人工选育等形成了丰富的胡椒种质资源。许多种质形态特征相似，传统分类手段鉴别困难，加上种质引进和生产管理疏漏，导致胡椒种质资源命名混乱和遗传基础不清，阻碍了其种质创新与共享利用。本项目拟以"SSR分子标记+DNA片段测序"实验体系，构建胡椒种质资源的分子身份证和DNA条形码，为准确鉴定提供可靠依据，解决种质同物异名、同名异物、品种混淆等问题；构建分子系统树，揭示胡椒种质间的系统亲缘关系，明确品种遗传基础，解决一些种质的分类疑问。本项目的实施可为胡椒种质资源鉴别、品种真实性和纯度鉴定、品种知识产权保护和优良品种推广等提供技术支持，对今后胡椒育种亲本选配、遗传改良、种质保护和核心种质构建等具有重要意义。

长期自然演化、突变、人工选育等形成了丰富的胡椒种质资源。许多种质形态特征相似，传统分类手段鉴别困难，加上种质引进和生产管理疏漏，导致胡椒种质资源命名混乱和遗传基础不清，阻碍了其种质创新与共享利用。本项目利用“SSR 分子标记+DNA 片段测序”实验体系，开展了胡椒种质资源的分子身份证和DNA条形码研究。利用NCBI数据库及自测胡椒转录组数据，设计开发出适用于胡椒遗传研究的EST-SSR引物358对，从中筛选出扩增稳定、多态性明显的13对引物揭示了胡椒种质资源的遗传多样性，并成功构建143份种质的分子身份证；通过候选基因片段有效使用性、种内种间变异和barcoding gap等综合分析，结合胡椒属植物分布范围广、多样性丰富的特点，建议将ITS作为胡椒属植物DNA条形码构建的首选基因片段；完成149份胡椒种质的ITS和127份种质的matK片段测序，生成了表征种质间系统亲缘关系的Neighbour-joining树系图，并基于ITS初步构建了48种胡椒属植物的DNA条形码。项目研究结果揭示了胡椒种质资源间的系统亲缘关系，解决了种质同物异名、同名异物、品种混淆等问题，为准确鉴定提供了可靠依据，对今后胡椒育种亲本选配、遗传改良、种质保护和核心种质构建等具有重要意义。