新疆野核桃（Juglans regia）核心种质的补充研究及遗传图谱构建

Xinjiang wild walnut(Juglans regia) is only distributed in chinese wild walnut Valley Nature Reserve, and it is precious natural wildlife resources of China. But, in the last few years，because of human activity damage and the spread of diseases and insect pests，the area of Xinjiang wild walnut forest is decreased gradually and the genetic breeding system and genetic diversity suffered from destruction．Thus，it is essential to take practical and effective measures to conserve the valuable genetic germplasm．It is troublesome to effectively maintain, research and utilize the more than five thousand of Xinjiang wild walnut germplasm resources, but the construction of core collection provides a convenient method to better research and utilize germplasm resource in Xinjiang wild walnut．Genetic linkage map is a foundation to QTL mapping and molecular marker-assisted Breeding. At present there had already reported a few pieces of walnut of genetic map, the research has been done little on the Xinjiang wild walnut genetic linkage map．This study constructed a Xinjiang wild walnut core germplasm using SRAP marker; a F1 segregation population Was derived from distant hybridization between J.regia f.mieroearPa as female parent and J.regia f.eardata as a male parent, and genetic linkage map for Xinjiang wild walnut was constructed based on SSR and SRAP markers．And identify quantitative trait loci(QTL)associated with leaf and the growth of the about the agonomic characters in the F1 population, lay a foundation for xinjiang wild walnut molecular marker assisted breeding and gremplasm improved.

新疆野核桃（Juglans regia）仅分布于我国新疆伊犁巩留县野核桃沟自然保护区内，是我国珍贵的天然野生资源。然而近年来由于人类活动的破坏以及病虫害的传播，新疆野核桃的遗传多样性日益遭到破坏，加强这一珍贵资源的保护迫在眉睫。然而面对五千多份新疆野核桃种质资源，只采用常规方法对其进行保护利用显得牵强无力，核心种质的构建为新疆野核桃种质资源的深入评价、有效保护和进一步深层利用开辟了新的途径。遗传连锁图谱是数量性状定位(QTL)及分子标记辅助育种等研究的基础，目前已经报道了几张核桃遗传图谱，但对新疆野核桃的研究尚属空白。本研究利用SRAP标记构建了新疆野核桃核心种质，并以新疆野核桃中小圆核桃类型与心型核桃的杂交F1代为作图群体，构建了一张新疆野核桃SSR和SRAP标记的分子遗传连锁图谱，并与叶片及生长等有关的农艺性状进行了QTL初步定位与分析，为新疆野核桃分子标记辅助育种和种质改良奠定基础。

新疆野核桃是我国栽培核桃的野生祖先，是我国非常珍稀的野生植物资源，但是目前对这一宝贵资源的研究还明显滞后于其他野生果树树种。本研究首次利用SRAP标记进行新疆野生核桃遗传多样性的研究的和核心种质的构建，结果显示群体的基因分化系数（Gst）的平均值为0.1152，说明新疆野生核桃群体存在中等分化；区域内的遗传多样性占新疆野生核桃总遗传多样性的86.61%，说明新疆野生核桃变异主要存在于区域内部。选择48个样本组成新疆野生核桃的核心种质，取样比例是原始种质的1.14%。在0.05水准下，实验所取核心种质与原始种质无明显差异，且核心种质的Ne、Nei's和Shannon’s指数的保留率分别为100.01%、100.02%、100.02%,说明本研究构建的野核桃核心种质能够很好地代表原始种质的多态性。构建的48份核心种质包含了新疆野核桃原始种质的树皮光滑程度、树高、枝条色泽、病(虫)害、果型、开花次序等所有变异。以新疆野核桃父母本及368株F1代为作图群体，对46对SSR和17对SRAP引物进行筛选，共检测出109个多态位点可用来进行后续的构图分析。获得了首张新疆野核桃遗传连锁图，包含有29个SSR和33个SRAP标记，该图共涉及到15个连锁群，总长为757.5cM，各连锁群长度在22.1cM-151.7cM之间，标记间的平均图距为12.22cM。最后将表型性状与两种分子标记做了关联分析，检测出与表型性状相关联的SSR标记位点13个，SRAP标记位点7个。研究结果为利用新疆野核桃种质资源进行育种选择和相关性状的基因分析提供了分子依据，并为新疆野核桃这一珍贵资源科学有效地保存、评价与鉴定奠定了一定的基础。项目资助发表核心论文3篇，待发表2篇。培养硕士生2名，其中2名已经取得硕士学位。项目投入经费50万元，支出25.6646万元，剩余经费24.3354万元，剩余经费计划用于本项目研究后续支出。