Study On Genetic Variation Of Yield Related Characters Of Populus Deltoides

Based on analysis of the investigated data in seedling stage and 8 year tree of the Populus deltoides clones,this paper studies the genetic variation of the main seedlings traits as well as the traits of old trees, and the correlation of yield related characters, then do research on the forecast capability of seeding stage traits for the growth of old trees, so as to have a scientific principle for the early selection. The main results are highlighted as follows:1 According of analysis of variance of important traits of the seedling stage clones and 8a tree clones, the results are shown that there are remarkable or extreme variations between the different Populus deltoides clones. High broad heritability and genetic variation coefficient in seedling stage plant type, seedling photosynthesis characteristic and plant type of old tree, indicate that there are enough space for genetic breeding, and good genetic gain are gained by selection.2 Annual growth of the seedlings of Populus deltoides clones show"slow to fast to slow"S-curve. The fit effect of the model indicates dynamic growth of seedling stage can be modeled well by Logistic equation. Based on the parameters t1=(a-1.317)/b and t2=(a+11317)/b ,annual growth of the seedlings can be divided into 3 stages: pre-growth phase, fast-growth phase, post-growth phase. The difference of growth rhythm of different clones are of significantly.3 The analysis of correlation indicates that the plant type traits of the seedling is correlative or negative with the growth traits of 8 years old tree; Seedling stage photosynthesis rate is significantly or extremely correlated with the yield traits of old tree (a=0.1 & a=0.05);The dynamic growth characters of seedling height and floor diameter at seedling stage are correlated little with the DBH traits of 8 years old tree, perhaps the counteracting each other between positive and negative effectivity of traits lead to individual trait is not enough correlated with yield characters of old tree.4 The principal components analysis indicates that first 3 or 4 principal components accumulated contribution ratio of the seedling plant type traits , the 8a tree plant type traits and the seedling dynamic growth characters,is 90.31%,81.89% and 94.03% respectively. The result indicates that focus ratio of principal components is very high,and numerous original information was contained.5 The seedling plant type and the seedling dynamic growth characters are applied to model the yield of 8a tree respectively. The test shows that all models can estimate well appearance of Populus deltoides clones. However, the true growth can not be estimated exactly by them. In order to ensure the accuracy, all models should be applied together, so that a more reliable principle can be used for the early selection.