Study On Populus Deltoides Hybridization And Genetic Variations Of Seedling Important Traits Of Hybrids

Through artificial control-pollination, hybrid populations of Populus deltoides×Populus deltoides and Populus deltoides×Populus simonii were established. And also studied the genetic variation of important traits included the growth character, the photosynthesis, and the resistance to Tetra lobulifera (Keifer) and Melampsora larici-populina Kleb and so on. At the same time, immature zygotic embryo culture experiment also has been holed. The major research conclusions were as follows:1, Selected Populus deltoides T120 and 1—52 and other nineteen male poplar as parents, 25 of 38 cross combinations obtained seeds, gained 1 090 hybrid seedling in total. Analysis of the growth traits, the photosynthesis, the resistance to acarid and rust showed that, there are significant difference among cross combinations whose number of seedling are more than 30.2, Estimation of heritability showed that the family heritability of ground diameter character and seedling height character is 0.8771 and 0.8825 respectively, which means initial selection can obtain certain genetic gains.3, Selected 3 excellent cross combinations in both growth and resistance from the hybrid population, through the analysis of principal components, classify and point system. And 20 superior seedlings individual also selected, the genetic gains of ground diameter are 42%~114% and the seedling height genetic gains rang from 24% to 64.39%.4, The cross experiment of Populus deltoides×Populus simonii obtained 130 hybrids, the intersectional hybrids have significant difference with parents in leaf morphological and branch number. Furthermore intersectional hybrids have very strongly resistance to Tetra lobulifera (Keifer), which may means Populus simonii is good material for anti-acarid breeding.5, The analysis of combining ability shows that general combining ability (GCA) of both male and female is not significant difference, the special combining ability (SCA) of cross combination is the main source of variation of basal diameter and seedling height.6, Experiment shows that, immature zygotic embryo culture can obtain success in 28 days only after pollinated; it is suggested to culture the immature zygotic embryo within seed vessel during the nonage, while inoculated without rind is better if pollinated after 40 days, which can avoid embryo vitrification.