Genetic Variations In Pulpwood Qualities Of Generation Of Open-pollinated Hybrid Larch And Multi-Traits Selection

This study was carried out in a 17-year-old-hybrid larch progeny test of open-pollinated families in Qingshan County, Heilongjiang province. With puplwood as a cultivated target. Analyze growth and wood traits of genetic variation, genetic parameter estimation, correlation analysis and comprehensive evaluation. The regulation of genetic variation between traits were comprehensively studied. The connection of traits were systematically studied. According to growth and wood traits, superior families can be choosed in Mudanjiang region. The main results showed that:1. Variance analysis:There were certain range of variation within the families. The coefficient of variation of the latewood were greater than the earlywood. There were abundant of variation in the volume, Late wood tracheid wall thickness-diameter ratio and ray proportion. Coefficients of variation were between 44.6%-85.3%. There were not abundant of variation in the HC, early wood MFA and tracheid proportion. Coefficients of variation were between 1.4%-8.1%, Latewood traits canbe choosed.2. There were significant differences between HC, earlywood and latewood MFA, tracheid length-width ratio, latewood radial diameter, latewood cell wall ratio, latewood tracheid wall thickness-diameter ratio and tracheid proportion. There are differences between volume, tacheid length, tangential diameter, earlywood and latewood number of cells per square millimeter.the family heritability were between 59.3%-92.7%. It was showed that these traits have potential for pulpwood selection.3. Correlations between Volume and HC were significant positively high, Correlations between Volume and latewood MFA, tangential diameter, latewood tracheid wall thickness-diameter ratio, tracheid proportion were positively high; Correlations between tracheid length-width ratio and latewood number of cells per square millimeter were negatively high. Correlations between Basic density and Volume were negatively high, Correlations between basic density and HC were significant negatively high. Correlations between basic density and latewood MFA, latewood tracheid wall thickness-diameter ratio were negatively high. Correlations between tracheid length-width ratio, latewood number of cells per square millimeter were positively high. Correlations between HC and tracheid length-width ratio, latewood number of cells per square millimeter were negatively high. Correlations between Tracheid length-width ratio and latewood cell wall ratio were significant negatively high. Correlations between latewood MFA and tracheid proportion were significant positively high. Improvements for the growtn traits should be focused, also with the improements for the basic density. 4. The genetic progress of the equal emphasis weights index I7 growh emphasis I8, wood traits emphasis restricted index I9 were the idealist index. Based on growth and wood traits, selected 3 families for pulpwood purpose:Xing'an7×Japan77-2 (Larix gmelinii7×Larix kaempferi77-2), Japan5×Chang77-3 (Larix gmelinii5×Larix kaempferi77-3) and Japan3×Xing'an9 (Larix kaempferi3×Larix gmelinii9). the family trait genetic gain:Volume (34.7%), late wood cell wall ratio(11.0%), HC(7.5%), tracheid wall thickness-diameter ratio (6.2%), tracheid length-width ratio (4.5%), latewood MFA(3.2%), latewood number of cells per square millimeter (0.3%). Improements for the growtn traits should be focused, also with the improvements for the wood traits.