| The selection of superior trees and collection of germplasm resources of Juglans mandshurica from 6 provenances in eastern Liaoning province were carried out by means of field survey.First of all,the absolute growth method is used to select the excellent individual tree,and the candidate superior tree is selected according to the age of the tree,the age class is divided,and the base line is drawn up by combining the height of the tree and the annual growth of the DBH,and the primary selection of the optimal tree is determined.Combined with the index of shape and quality,the selected tree was selected by the method of score.The effects of different environment and climate conditions on the growth and growth characters of Juglans mandshurica from different sources were analyzed by comparing the differences of growth characters and selection of superior trees in different sources of Juglans mandshurica.The kernel types were classified according to the phenotypic characteristics,and the phenotypic characters were measured and the correlation analysis was carried out by means of the single-plant seed-picking and mixed-seed collection of the selected superior trees and the mixed seed collection of Juglans mandshurica from the provenance.The phenotypic variation of kernel and the correlation among different traits were compared.This study provides a theoretical basis for further understanding the variation law of geographical provenance of Juglans mandshurica,rationally exploiting and utilizing precious resources of Juglans mandshurica,and carrying out the breeding of improved varieties.1.The age of the tree was estimated by the outer 7 cm method,and it was satisfied that the age of the tree was between 30 and 80 years,and that the number of candidate dominant trees was 202;By using absolute growth method,the average annual growth of tree height and diameter at breast height plus half of the standard deviation was taken as the base line standard,and 24 primary superior trees were determined by the method of absolute growth.Combined with the form and quality index scoring method,the height under the active branch,the central diameter and the north-south crown width were determined as the shape-quality index,and the average value was used as the evaluation criterion.The conditions were satisfied when the score was ? 0.5,and 14 excellent trees were selected,and the selection rate was 6.93 percent.2.Among the 6 provenances of Juglans mandshurica,most of them were Qingyuan and Xinbin superior trees,but the highest selection rate of Qingyuan superior trees was 11.43 per cent,and no superior trees were selected in Dandong.The number of 14 selected dominant trees is BH31,BH27,HH25,HH18,XH28,XH19,XH24,XH45,QH6,QH10,QH22,QH24,FH6 and FH31 respectively.According to the analysis results,the average annual growth of DBHof re-selected superior tree was significantly higher than that of candidate superior tree,the height,DBH,annual growth of tree height,and the height of active branches were significantly higher than those of candidate superior tree,and the average annual growth of tree height was significantly higher than that of candidate superior tree.The mean growth indexes of central diameter,north-south crown width and east-west crown width were also larger than those of candidate dominant trees,but the mean of stem-shape roundness and height-diameter ratio were slightly lower than those of candidate dominant trees.By analyzing the growth of Juglans mandshurica from six source areas,it can be seen that the annual growth of tree height and DBH of Xinbin is the largest,that of Qingyuan is the highest,the DBH,the height of active branches,the central diameter and the mean of north-south crown width are the largest.3.Taking the growth characters of Juglans mandshurica from different provenances as materials,combined with environmental and climatic factors,the correlation analysis of altitude,canopy density,slope with DBH,tree height and under-shoot height was carried out and different slope positions were carried out.The growth characters of Juglans mandshurica in slope direction were analyzed by variance analysis.The results showed that altitude and canopy density were positively correlated with DBH,tree height and height under living branch,while slope was positively correlated with height under living branch,but not with DBH and tree height.When studying the effect of slope position and slope direction on the growth characters of Juglans mandshurica,the slope position mainly affects the tree height,and the middle slope position has the best height growth,and the overall growth condition is also the best in the middle slope position of Juglans mandshurica.The correlation between growth characters of Juglans mandshurica and climate and selection rate of superior trees was analyzed.The results showed that the average annual temperature was negatively correlated with the height of trees,and negatively correlated with the height of living branches and the rate of selection of superior trees.The mean annual precipitation is negatively correlated with DBH,and the maximum temperature is negatively correlated with DBH annual growth and the ratio of height to diameter.4.The phenotypic variation diversity of Juglans mandshurica kernel from different provenances was studied.Through the analysis of the kernel shape,apex,longitudinal edge and inter-edge wrinkle depression of Juglans mandshurica from 6 source areas,it can be roughly divided into 12 types.The results of variance analysis show that: there were significant differences in the longitudinal diameter,lateral diameter,kernel weight and shell thickness between seed provenances,significant differences in the transverse diameter,single kernel weight,suture thickness,kernel yield and nut roundness index between seedprovenances,and no differences in the mean of three diameters between seed provenances.The variation coefficients of 10 phenotypic characters of Juglans mandshurica were analyzed and the results showed that the variation coefficients of shell thickness and suture thickness were the highest,which were high variant,longitudinal diameter,single kernel weight,kernel weight and kernel yield were middle variant.Transverse diameter,lateral diameter,nut roundness index and three-path mean coefficient of variation were the lowest,which were low variant.The phenotypic characters of Juglans mandshurica kernel from different provenances were analyzed and compared.The results showed that the variation coefficients of different phenotypic characters of six provenances showed the largest variation coefficients of shell thickness and suture thickness.The mean value was between22.59 and 25.18 per cent;The variation coefficients of transverse diameter,lateral diameter,nut roundness index and three-path mean value were 7.56%-9.30% and 10.6-18.58%,respectively.The frequency distribution map was made by grouping 120 kernel phenotypic characters according to their size.The results showed that the frequency distribution of kernel longitudinal diameter had double peaks except for kernel longitudinal diameter.In addition,the frequency distribution maps of other phenotypic traits were single peak value,which obeyed normal distribution.Cluster analysis was carried out on the phenotypic traits of 120 kernels from 6 provenances.At 6 threshold,cluster analysis was divided into 5 groups.The maximum(minimum)kernel yield and the smallest(maximum)roundness index of nuts were clustered into one group,and the other traits had a good degree of aggregation. |
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