Abstract:

Based on 810 molecular markers(784 AFLP markers and 26 SSR markers),obtained from the 87 individuals of F₂ 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 9.69cM. With the LOD≥2.0 and scan scale=2.0cM, 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.

Key words: Populus deltoides×, P. cathayana, Wood property, QTLs mapping