Study On Genetic Variation Of The Half-Sib Progeny And Superior Families Selection Of Acacia Crassicarpa

In this research,201half-sib families of Acacia crassicarpa have been studied, by measuring wood quality of Acacia crassicarpa progeny forest, this research has studied genetic variation of wood quality characters, genetic correlations between characters, correlations between wood quality and growth characteristics of families and so on which growth characteristics were different. Superior families and superior individual with good growth character, stem straightness and wood quality were selected by multi-trait index method; the main results were as follows:1. Baced on the201half-sib families of Acacia crassicarpa conducted forest growth determination, all the families index values are calculated using an exponential equation by a comprehensive index method. Choose the families whose index value in the top20, medium20and at the end of20.These families were representative of the population three groups which is good, medium and bad.2. The result of progeny test of half-sib families of Acacia crassicarpa at3year old shows:the variation among families in tree height, DBH, stem straightness and volume characters were extremely significant correlation among families, there were a lot of genetic variations among families;For3groups of Acacia crassicarpa families, there was no significant for straightness. There was no significant difference among groups and between groups by fiber length, fiber width and ratio of fiber length to width. For basic density, there was no significant difference among groups but there was significant difference between different groups.3. The result of progeny test of half-sib families of Acacia crassicarpa at3year old shows:the family heritability of tree height, DBH and volume contained moderate genetic level, family heritability of stem straightness contained low genetic level; For3groups of Acacia crassicarpa families, for the family heritability, fiber length, fiber width, ratio of fiber length to width, tree height, DBH, volume and stem straightness were controlled by medium degree and more than that degree genetic. The basic density was controlled by low and medium degree genetic.4. For tree height, DBH, volume, the correlation index between progeny and maternal plant was not significant, but for stem straightness, for progeny in2year and3year between maternal plant was significant correlation and extremely significant correlation; For201half-sib families of Acacia crassicarpa, there showed positive correlation which was extreme significant between tree height and DBH. For phenotype and genetic correlation there was extremely significant correlation of positive correlation by stem straightness between tree height, DBH and volume; For3groups of Acacia crassicarpa families, for phenotype and genetic correlation there were weak and non-significantly negative correlation between basic density and fiber length, and there were extremely significantly negative correlation when basic density compared with fiber width and ratio of fiber length to width. For phenotype and genetic correlation there were weak and non-significantly negative correlation between fiber length and fiber width, and there were extremely significant positive correlation. For phenotype it showed non-significantly negative correlation between basic density and tree height, DBH and Volume. For phenotype there were significant negative correlation between fiber width and DBH, for the rest of growth characters and wood quality characters there was no significant correlation.5. Under the selection rate of10%for superior families, the basic density, the average genetic gains of fiber length, ratio of fiber length to width, tree height, DBH, stem straightness, volume were-0.31%,1.18%,4.10%,3.25%,10.24%,0.23%,24.68%. For basic density, the genetic gains of No.233was the highest; For fiber length, the genetic gains of No.74was the highest; For tree height, DBH and volume, No.356showed highest genetic gains; For stem straightness, No.60and No.233showed highest genetic gains. Among this, the superior family No.60, it only showed-1.77.4%negative genetic gain in basic density, and in fiber length, fiber width, ratio of fiber length to width, tree height, DBH, stem straightness and volume it all showed positive genetic gains.6.30-60、17-174、3-233、29-74、15-288、30-356were selected as superior individual by simple index method. For cooperating with genetic gain, family No.74showed the highest genetic gains in basic density as0.51%, family No.74also showed highest genetic gains in fiber length as10.56%, family No.356showed highest genetic gains in tree height as22.39%, family No.60showed highest genetic gains in stem straightness as3.62%.