Analysis Of Differences In Growth And Photosynthetic Physiological Characteristics Of Fraxinus Mandshurica

Fraxinus mandshurica Rupr.is one of the main afforestation trees in Northeast China,and is also a highly ornamental greening tree species.In this study,150 Fraxinus mandshurica clones（10 Fraxinus mandshurica provenances）from the Qingshuihe Forest Farm of Lushuihe Forestry Bureau of Jilin Province were used as materials to measure their trunk traits,leaf phenotypic traits,leaf nutrient elements,and photosynthetic physiology.The measured data were analyzed by variance analysis,genetic variation parameter analysis,mean value analysis,correlation analysis,principal component analysis,and cluster analysis,Finally,excellent clones and excellent provenances were selected through comprehensive evaluation of multiple traits,aiming to provide materials for Fraxinus mandshurica landscaping and production afforestation;At the same time,the construction of Fraxinus mandshurica forest seed orchards and the improvement of plantation varieties were accelerated.The specific research results are as follows:（1）The analysis results of tree height,ground diameter,crown diameter,height growth in2021,height growth in 2020,and height growth in 2019 measured in 2022 for tree stem traits showed that（except for the insignificant difference in crown diameter among different provenances）,each trait was found to be among different clones,provenances,and clones×Flora,provenance×The differences between the groups were extremely significant（P<0.01）;There was a significant positive correlation between the trunk traits of each tree.A comprehensive evaluation and selection was conducted on 150 clones with a 10%selection rate,and 15excellent clones and 1 excellent provenance were selected.（2）The phenotypic traits of leaves（fresh weight,dry weight,area,length,width,shape index,specific leaf area,and dry matter content）were measured and analyzed.The results showed that the variation coefficient of phenotypic traits ranged from 15.62%to 45.08%;The variation range of repetition force is 0.32～0.84;Heritability ranged from 0.23 to 0.91;There is a highly significant positive correlation between fresh leaf weight and leaf dry weight,leaf area,leaf length,and leaf width;According to the results of cluster analysis,when the Genetic distance is about 3,provenances can be divided into four categories.The first category is provenance 1,5,3,9,8,6;The second largest category is Provenance 10;The third major category is provenance 4 and 7;The fourth major category is Provenance 2.（3）The determination and analysis of nutrient elements in leaves showed that the variation coefficient among various traits ranged from 1.22%to 68.46%;The repetition force varies from 0.06 to 0.84;The variation range of heritability is 0.63～0.95;According to the results of principal component analysis and correlation analysis,Mn,Zn,Cu,K,Ca,and Fe were selected.150 clones were evaluated and selected with a 10%selection rate,and 15excellent clones and 1 excellent provenance were selected.（4）The analysis of net photosynthetic rate,transpiration rate,stomatal conductance,and intercellular CO₂concentration in photosynthetic physiological traits showed that transpiration rate and net photosynthetic rate reached extremely significant levels among different clones and sources（P<0.01）;（Except for a highly significant negative correlation between net photosynthetic rate and intercellular CO₂concentration）,all photosynthetic physiological traits showed a highly significant positive correlation.Based on the comprehensive analysis results,FM117 had the highest net photosynthetic rate among 150 clones;The highest net photosynthetic rate among the 10 sources is source 3,among which the Huinan source has excellent photosynthetic physiological and trunk traits.