| Aleurites Montana(Lour.)is a deciduous tree of the genus Aleurites in Euphorbiaceae.It is a unique woody oil tree in China.In recent years,the planting area of Aleurites Montana in China has been growing rapidly,and it has exceeded 20000hmi2 in southern Hunan alone.However,the selection of Aleurites Montana clones is relatively backward at present.The superior clones of Aleurites Montana have not been selected in Hunan,and the seedlings are used for afforestation in production,resulting in the low unit area yield of Aleurites Montana.Therefore,it is an urgent need for the development of the Aleurites Montana industry to select excellent individual plants and breed clones by grafting.In this paper,the 5000 hm2 thousand year old Aleurites Montana which has entered the full fruit stage in the south of Hunan Province is selected as the best stand.According to the phenotypic indexes such as the number of fruit per plant,fruit yield per plant,tree size,tree shape and fruit aggregation degree,320 thousand year old Aleurites Montana are preliminarily determined,and 32 good trees are selected by check.Then,the correlation and phenotypic variation of the tree were analyzed according to 15 economic indexes,such as the total quality of fresh fruit,the single quality of fresh fruit,the height of fruit,the diameter of fruit,the total number of fruit,the yield of fruit per plant,the DBH,the height of tree,the thickness of fruit shell,the quality of dry seed,the yield of dry seed,the yield of fresh fruit,the content of fat,the yield of oil per plant and the oil content of seed A comprehensive evaluation model was set up to select the best individual plant.At the same time,a set of grafting propagation technology system was established in spring and autumn respectively.The results of this study laid a foundation for the cultivation of good clones of Jatropha curcas.The main conclusions are as follows:1.Phenotypic variation analysis:there are great differences in the observation indexes of the selected excellent trees.The coefficient of variation of phenotypic indexes ranges from 6.2%to 54.15%,among which the largest coefficient of variation is oil production per plant(54.15%),fruit production per plant(46.91%)and total fruit number(46.00%),and the smallest coefficient of variation is fruit diameter(6.2%).The large coefficient of variation indicates the great potential of selection.2.Correlation analysis of fruit quality characters:the correlation analysis of fruit quality characters of 32 selected excellent trees showed that the quality of fresh fruit was positively correlated with shell thickness,fruit height and fruit diameter,negatively correlated with seed yield of fresh fruit,negatively correlated with dry kernel quality,k ernel oil content and fat content,positively correlated with oil yield of single plant,and positively correlated with seed yield of fresh fruit There was a negative correlation between the kernel yield and the kernel oil content;there was a significant positive correlation between the fresh fruit seed yield and the kernel yield and the fat content;there was a significant positive correlation between the kernel yield and the kernel oil content,and there was a significant positive correlation between the kernel yield and the fat content.3.Three Principal component analysis,construction of comprehensive evaluation model and cluster analysis:four principal components were extracted by principal component analysis.The first principal component is yield and fruit type factor,and the variance contribution rate is 30.9%.The second principal component is economic quality factor,and the variance contribution rate is 26.7%.The third principal component is phenotype factor,and the variance contribution rate is 8.2%.The fourth principal component is tree factor,and the variance contribution rate is 8.5%The cumulative variance contribution rate of the four principal components is 84.4%.The comprehensive evaluation model of the fruit quality of Aleurites Montana is established:F=a1z1+a2z2+a3z3+a4z4.Cluster analysis divides 32 Aleurites Montana trees into three groups,including 7 in class Ⅰ,12 in class Ⅱ and 13 in classⅢ.The comprehensive properties of in class Ⅰ excellent trees are the best,which can be determined as the target excellent trees.4.Study on grafting technology of Aleurites Montana in spring:Using The survival rates of budding,cutting and splitting were 65.00%,53.33%and 36.67%,respectively.There was significant difference between budding and splitting,but there was no significant difference between them.The average survival rates of one-year rootstock and two-year rootstock were 47.9%and 23.33%,respectively The survival rates of 20 cm,30 cm and 50 cm were 53.33%,65.00%and 40.00%,respectively.There were significant differences between 30 cm and 50 cm,20 cm and 30 cm,20 cm and 50 cm,respectively There was no significant difference in cm.The average grafting survival rate of 1-year-old rootstock bagged was 51.67%,39.44%and that of 1-year-old rootstock bagged was 39,44%.The average grafting survival rate of 1-year-old rootstock was 46.92%,29.83%and 16.83%respectively,and the average grafting survival rate of 3 kinds of scions was 46.92%,29.83%and 16.83%during budding,cutting and splitting There were significant differences in the survival rate of grafting.The best combination of grafting technology in spring is budding+1-year-old rootstock+bagging+semi lignified green branch,and the highest grafting survival rate is 80%.5.Study on grafting technology of Aleurites Montana in autumn:after the scion is accelerated,the survival rates of budding,cutting and splitting of 1-year-old rootstock are 61.67%,48.33%and 28.33%respectively,and there are significant differences among the three grafting methods;after the scion is accelerated,the survival rates of budding,cutting and splitting of 1-year-old rootstock are 68.33%,51.67%and 33.33%respectively,with an average of 51.11%.The survival rates of budding,cutting and splitting of 2-year-old rootstock are 68.33%,51.67%and 33.33%respectively The survival rate of split grafting was 50.00%,20.00%,15.00%,28.33%on average,and the average survival rate of one-year-old was 1.81 times that of two-year-old;the survival rate of one-year-old rootstock grafting was 76.08%and that of non germination was 52.5%,the former was 1.45 times that of the latter;the average survival rate of one-year-old rootstock bagging was 49.16%and that of non bagging was 37.19%,the former was 1.31 times that of the latter;the survival rate of one-year-old rootstock bagging was 49.16%and that of non bagging was 1.31 times that of the latter The average grafting survival rate of 1-year-old stock was 53.89%,36.66%and 31.94%for semi lignified green branch,lignified green branch and brown old branch.The average grafting survival rate of semi lignified green branch was 1.46 times of lignified green branch and 1.68 times of brown old branch.The best combination of autumn grafting technology is budding+1-year-old rootstock+sprouting+bagging+semi lignified green branch.The highest grafting survival rate is 83.75%.Through this study,a set of index system for selection and evaluation of excellent trees of Jatropha curcas was established,excellent single trees were selected,grafting technology of Jatropha curcas was improved,which laid a foundation for clone breeding of Jatropha curcas. |
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