杨属派间杂种苗期抗旱相关性状QTL定位及新品种选育

Poplar is one of the most important afforestation tree species in northern China. But poplar has poor growth or even die due to drought and rainless environment, and economic and ecological benefit are greatly affected. It is very important to cultivate new drought-tolerant poplar varieties with fast growth which are adaptable in the arid regions of northern China. Populus deltoides CL. ‘Danhong’ and P. simonii, which belong to Aigeiros section and Tacamahaca section, respectively, have significant difference of drought resistance, and could be used as good germplasms for QTL mapping. In this project, ‘Danhong’ as female parent and P. simonii from Tongliao of Inner Mongolia as male parent, a large sample hybrid population was established. Using SSR markers screened from the scope of genome-wide, imply genetic mechanism of morphology separation from inter-section hybrid, construct high density genetic linkage map and carry QTL mapping for drought resistance related traits. Main effect QTL will be increased density to excavate and analyze main effect candidate genes controlling drought-resistant, lay the foundation for molecular marker assisted breeding of drought resistance for Populus. Through field test, new poplar varieties with fast growth, drought resistance and improvement adaptability, will be planted in North China from breeding hybrid populations.

杨树是我国北方重要造林树种之一，但因干旱少雨，杨树常生长不良甚至死亡，经济效益和生态效益受到极大影响，培育适合我国北方干旱地区生长的速生抗旱杨树新品种具有重要的意义。本研究利用杨树派间两个对适应性、干旱抗性差异较大的优良种质美洲黑杨（丹红杨）和小叶杨（内蒙古通辽）作为亲本，建立大样本杂交群体，从全基因组范围内筛选SSR标记，解析杨树派间杂交子代性状分离的遗传机制，构建高密度遗传连锁图谱，对抗旱相关性状进行QTL定位，并对主效QTL区间标记进行加密，发掘控制杨树抗旱主效候选基因，为杨树抗旱分子标记辅助育种服务。通过田间试验，从杂交群体中选育适合我国华北地区生长的具有速生性、抗旱性和适应性均提高的杨树新品种。

杨树是我国北方重要造林树种之一，培育适合我国北方干旱地区生长的速生抗旱杨树新品种具有重要的意义。本研究利用杨树派间两个对适应性、干旱抗性差异较大的优良种质美洲黑杨（丹红杨）和小叶杨（内蒙古通辽）作为亲本，获得F1杂交群体，构建高密度遗传图谱，解析杨树派间杂交子代性状分离的遗传机制，对叶形、生根、抗旱等性状进行QTL定位，发掘控制杨树重要性状候选基因，为杨树分子标记辅助育种服务。通过田间测定林，选育适合我国华北地区生长的速生、抗旱和适应性强的杨树新品种。. 对丹红杨×通辽1号杨双亲及500个子代基因组重测序开发单核苷酸多态性标记（SNP），构建高密度遗传图谱，构图标记共5796个，连锁群总数为19个，总图距为2683.8cM，标记间平均间距为0.46cM。对丹红杨×通辽1号杨杂交群体叶形、生理、生根、抗旱性、田间生长等表型性状测定和遗传分析，检测到叶形生理性状、生根和径生长、以及抗旱性相关的QTLs 464个、233个和208个，分别筛选到208个、640个和187个候选基因。开发了一个与叶片相对含水量相关联的抗旱性分子标记np2841，发现STHK、RAB、CYC、SHKR、APX、RCCR和PtAAAP19等相关重要基因17个。经过田间试验和温室抗旱测定，筛选出抗旱性优于父本10个杂交子代，申报植物新品种权2项。在国内外期刊上发表论文7篇，培养硕博士研究生2名，其中在读博士研究生1名。. 本项目利用高密度遗传图谱对杨树重要性状进行遗传解析，获得相关性状大量分子标记、QTLs位点，发掘了一些重要基因，丰富了的杨树育种基因资源，对杨树分子标记辅助育种和遗传改良具有重要意义，将为我国林业生产提供抗旱速生杨树新品种。