美洲黑杨×青杨木材性状QTLs定位研究

QTLs Mapping for Wood Properties of Populus deltoides×P. cathayana

利用来自 87个F2 代单株的 81 0个标记 (784个AFLP标记和 2 6个SSR标记 )构建了美洲黑杨×青杨杂种分子连锁遗传图谱。该图谱包括 1 9个主要连锁群 ,共有 36 8个标记 (35 6个AFLP标记和 1 2个SSR标记 )。框架图总图距为 3382 4cM ,平均标记间距为 9 6 9cM。利用区间作图法在LOD≥ 2 ,检测区间为 2cM条件下检测到 8个与木材性状有关的QTLs。其中与木材基本密度关联的 3个QTLs贡献率分别为 2 7 1 %、2 7 1 %、2 5 5 % ,与微纤丝角关联的QTLs贡献率为 1 8 6 % ,与纤维长度关联的QTLs贡献率为 4 8 9% ,与纤维宽关联的 3个QTLs贡献率分别为 1 7 4 %、2 7 4 %和 4 8 3%。这 8个QTLs遗传作用方式均为超显性 ,其中只有 2个与基本密度关联的QTLs来自于美洲黑杨 ,其余 6个均来自于青杨。

Based on 810 molecular markers(784 AFLP markers and 26 SSR markers),obtained from the 87 individuals of F 2 population from Populus deltoides×P. cathayana , a hybrid molecular linkage map was constructed. In this map, 356 AFLP makers and 12 SSR markers, 368 makers in total, were distributed in the 19 major groups. This map covered 3 382 4 centiMorgan (cM) of the genome in length, and the average distance between two markers was 9 69?cM. With the LOD≥2 0 and scan scale=2 0?cM, total 8 QTLs for wood properties were obtained by using interval mapping (IM) in this map. The phenotypic variation contributions (PVCs) of 3 QTLs for wood basic density were 27 1%,27 1% and 25 5%,respectively; PVC of 1 QTL for microfibre angle was 18 6%;PVC of 1 QTL for fibre length was 48 9%; and PVCs of 3 QTLs for fibre width were 17 4%,27 4% and 48 3%. Gene actions of all QTLs were overdominance. The two original parents made different contributions to the QTLs of their hybrid progeny. The P. deltoides parent contributed 2 QTLs, which associated with wood basic density, and P. cathayana contributed 6 QTLs to their hybrid progeny.