| In this study,the offspring of superior plus trees on Fraxinus mandshurica were surveyed about growth trait(tree height,DBH,ground diameter,volume of timber).The offspring of superior plus trees (in54families) were9years old and were planted in3test points which are Dailing District Heilongjiang Province Yichun City, Mao’er Mountain experiment forestry farm of Northeast Forestry University in Heilongjiang Province Shangzhi City and Lu Shui He forestry bureau in Jilin Province.Volunteers’ families in every test point were sorted according to the level of growth(from excellent to inferior) on the basis of the survey result of growth trait,and the superior families in growth aspect were selected preliminarily according to certain selection principle.In order to examine the level of any other traits about the selected superior families which was on the basis of growth trait and get to know the degree of correlation between growth trait and any other traits,taking the offspring of Fraxinus mandshurica in Dailing for example,we selected10families(including the contral) according growth level of high,medium and low.These10families were used for biomass,carbon content,nitrogen content,and the coumarins content assaying.Through establishing the regression equation on growth and biomass,and the regression equation on growth and carbon content of single plant,we acquired the biomass and single plant carbon reserve of any other tested families. This study has important guiding significance for the genetic improvement of Fraxinus mandshurica. The results were as follows:1.Growth trait variation of tested families:The differences of tree height, DBH,ground diameter and volume of timber among different families was extremely significant,and the tree height,DBH,ground diameter and timber volume among families had wide variation extent;tested families in3test points were all like that.The family heritability, the genetic variable coefficient and the genetic gain of timber volume of tested families in Dailing district all exceeded any other growth traits.The family heritability of timber volume was69.24%,whose genetic variable coefficient and genetic gain were38.98%and23.45%.The tree height’s family hereditary of the offspring of Fraxinus mandshurica in MaoEr hills was higher than any other growth traits,and the tree height’s family heritability was63.85%.The family hereditary of any other growth traits were all in the medium range.The genetic variable coefficient and the genetic gain of timber volume were highest,whose genetic variable coefficient and genetic gain were24.28%and12.05%.For all growth traits of tested families in Lu Shui He,the tree height’s family hereditary was higher than any other growth traits,and the tree height’s family heritability was85.15%.The genetic variable coefficient and the genetic gain of timber volume were highest,whose genetic variable coefficient and genetic gain were29.61%and26.28%.The average level of mass growth of tested families among three test places were compared,and the compared result was as follow:MaoEr hills>Dailing District>Lu Shui He.We had selected two families whose growth traits were superior in all three test fields according to the superior families which were selected in each place respectively.The growth of the two selected families were more than10.82%-13.42%higher than the general average of three test points.2.The correlation analysis between growth trait and any other traits(photosynthetic parameter,biomass,carbon reserve and coumarins content):The degree of correlation between growth trait and photo synthetic parameter was very low,and there existed high positive correlation between growth trait and biomass.The degree of correlation between growth trait and the carbon content rates of each organic was low,but there existed a high positive correlation between growth trait and the carbon reserve of single plant.The degree of correlation between growth trait and nitrogen content was above the medium level,and that between growth trait and coumarins content in bark was very low.3.Variation analysis of photosynthetic parameter about tested families.The differences of net photosynthetic rate, stomatal conductance and transpiration rate among tested families were all highly significant.The results of genetic parameter analysis showed that the family heritability of net photosynthetic rate (53.11%) was in the medium level,and the genetic variable coefficient(8.61%) and genetic gain(2.28%) of that were all low.The family heritability (75.63%and73.13%),genetic variable coefficient(31.43%and41.18%) and genetic gain(21.26%and23.80%) of any other photosynthetic parameter(stomatal conductance and transpiration rate) were all high.In this trial,seven families whose level of photosynthetic parameter were highest had been elected preliminarily.The photosynthetic parameters of the selected families were all10.96%-66.72%higher than general average,and12.11%-86.75%higher than control.4.The variation of biomass traits on tested families:The differences of biomass trait among tested families were highly significant.The results of genetic parameter analysis showed that the family heritability(71.65%),genetic variable coefficient(38.51%) and genetic gain(21.06%) of biomass trait were all high.In this trial,ten superior families in aspect of biomass trait had been elected preliminarily.The biomass of the elected families were all28.25%-200.84%higher than average,17.76%-176.24%higher than control.5.The variation of tested families in aspect of carbon reserve of single plant:The differences of carbon content of single plant among tested families were extremely significant.The results of genetic parameter analysis showed that the family heritability(73.90%),genetic variable coefficient(31.05%) and genetic gain(21.87%) of carbon reserve of single plant were all high. In this trial,ten families who possess biggest carbon reserve of single plant had been elected preliminarily.The elected families were all34.20%-162.78%higher than average,42.22%-178.48%higher than control. 6.In this paper,three families with higher nitrogen content in trunk were selected from the ten families.The nitrogen content in trunk of the selected families were30.39%-57.06%higher than average,40.28%-68.97%higher than control.7. The families with higher coumarins content in bark were selected,include2families for mandshurin,1families for aesculin and,5families for aesculetin..These selected families were all17.64%-36.04%higher than average,16.44%-93.32%higher than control.8.On the base of growth traits(tree height,DBH,ground diameter,volume of timber)、 photosynthetic parameter(net photosynthetic rate、 stomatal conductance、transpiration rate)、biomass、and carbon content of single plant,10families each trait of which was superior were selected by weighing composite index.The level of composite index of selected families were all22.05%-50.24%higher than average and34.79%-65.02%higher than control. |
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