Study On Genetic Variation Of Parents And Progenies In Larix Kaempferi Seed Orchard

The evaluation and selection of parents and progeny is the important content of the upgrade and reconstruction seed orchard.In order to evaluate the excellent clones and families of Larix kaempferi,the excellent clones and families were evaluated by the method of multiple-traits comprehensive,the selected elite clones and families could provide materials for the upgrading and upgrading of seed orchard and the basis for registration of improved material.The study used the parents and progeny of L kaempferi seed orchard as materials,which was in Wudaogou,Jilin Province,carrying out the genetic variation researches on the growth traits,wood properties,phenophase,fruiting traits of parents and the growth traits,wood properties of progeny were taken as materials,respectively.To explore the genetic variation of different materials,parents and offspring were evaluated and selected,in order to provide reference for the upgrading and upgrading of seed orchard.The main results were as follows:(1)The growth traits of L.kaempferi clones in different provenances were investigated.The results of ANOVA showed that there exited significant difference in provenances and clones among all growth traits.The phenotype variation coefficients and genetic variation coefficients of growth traits were higher.Dongfeng provenance was selected as superior provenance.Dongfeng L.kaempferi clones were taken as materials,the tree height and diameter at breast were investigated over many different growth years.The results of ANOVAshowed that there exited significant differences between clones and tree ages.There were significant positive correlations between tree height and diameter at breast in different growth year.Using the method of multiple-traits comprehensive with 10%selection rate.7 clones were selected as excellent clones,which genetic gains of tree height and diameter at the breast height were 6.46%and 13.99%,respectively.The early selection time was proposed,about 7-year-old was the most proper age for L.kae,mpferi clone.(2)The growth traits of L.kaempferi half-sub falilies in different provenances were investigated.The result of ANOVA showed that there exited significant difference among all variance sources.The phenotype variation coefficients and genetic variation coefficients of tree height and diameter at the breast height increased with the tree growth.The falily heritability of tree height and diameter at the breast height were higher,the single plants heritability of tree height and diameter at the breast height were lower.There existed significant positive correlation among tree height and diameter at the breast height of different growth year in provenance.The growth traits of Lanshan provenance was superior to other provenances.The tree height and diameter at breast of Lanshan L.kaempferi half-sib families were investigated over many different growth years.The variance components of tree height and diameter at breast height increased with the tree growth.The heritability of tree height and diameter at breast height were higher,respectively.There were significant positive correlations between all growth traits in different growth years.Using the method of multiple-traits comprehensive,6 families were selected as elite families,which genetic gains of height and diameter at breast height were 10.53%and 15.79%.45 individual plants were selected as elite individual plants.which average values of these elite individual plants were 23.47%higher than the overall average for height.The early selection time was proposed,about 6-year-old was the most proper age for L.kaempferi family.(3)Sixty L.kaempferi clones in four provenances were taken as materials,the growth traits and wood properties were investigated.The results of ANOVA showed that there exited significant differences in all variance sources.The phenotype variation coefficients(6.65%to 25.66%)and genetic variation coefficients(3.42%to 22.27%)were wide.The clones repeatability of all traits were higher than 0.51.Using the method of multiple-traits comprehensive,6 elite clones were selected based on growth traits,wood properties and both growth traits and wood properties together,which genetic gains ranged from 5.27%to 21.53%,8.02%to 21.95%and 4.27%to 18.07%,respectively.The growth traits and wood properties of these offspring of L.kaempferi were investigated.The phenotype variation coefficients and genetic variation coefficients were also wide.The families heritability of all traits were higher than 0.76.Using the method of multiple-traits comprehensive,6 elite clones were selected based on growth traits,wood properties and both growth traits and wood properties together,which genetic gains ranged from 9.20%to 37'55%?9.32%to 28.82%and 6.20%to 22.62%,respectively.Correlation analysis was carried out for parent and offspring,there were extremely significant positive correlations between all growth traits in parents and offspring(4)The phenophase and seed yield of L.kaempferi clones in different provenances were investigated.The results of ANOVA showed that there exited significant difference among phenophase and fruiting traits.The repeatability of all phenophase were higher than 0.84.There existed significant positive correlation among all index.There was a certain synchronicity between male and female flowers in whole flowering phase.According to the time order of blossom of male and female flowers,6 clones could be determined to protandrous type,9 clones protogynous type and 72 clones homogamy type.The total of seed yield for Dongfeng provenance were superior to other provenances in five years,the regularity of fruiting follows the rule of varied salience every year.With 10%selection rate,9 clones were selected as excellent clones,which genetic gains was 19.40%.(5)The tree height and diameter at the basic height of L.kaempferi full-sib families were investigated.The results of ANOVA showed that there exited significant differences among all variance source.The phenotype variation coefficients of tree height and diameter at the basic height were 30.23%and 21.51%,the genetic variation coefficients of tree height and diameter at the basic height were 15.98%and 16.99%.The families heritability of tree height and diameter at the basic height were 0.94,the individual plants heritability of tree height and diameter at the basie height were 0.52,respectively.The general eombining ability of Sanpeng 04 and Sanpeng 37 were higher,which were suitable as a good parent to build the improved seed orchard.According to the calculating of special combining ability,Dongfeng 18×Lanshan 25.Dongfeng 81 × Lanshan 25,Sanpeng 98 × Sanpeng 74 and Linjiang 34 x Lanshan 28 were selected as elite hybrids combinations,which were suitable to build the special combining ability seed orchard.Using the method of multiple-traits comprehensive,7 families were selected as elite families,which genetic gains of tree height and diameter at the basic height were 35.02%and 29.01%,respectively.50 individual plants were selected as elite individual plants,which genetic gains of tree height and diameter at the basic height were 47.92%and 34.67%,respectively.The selected elite clones and families could provide materials for production and applications,the selected elite individual plants and parents can provide security for upgrading seed orchard,the early selection time can provide reference for elite seed breeding,the research route could supply the theoretical foundation for genetic improvement of other tree species.