Initial Selection Of Ginkgo Superior Clones For Production Of Nuts

Ginkgo biloba L. is the only extant plant of Ginkgoales, and has high economic and scientific value. This study was carried on system analysis to biology characters of 39 clones, seed traits and chemical component, meanwhile obtained every characters and component correlation situation and variation situation, moreover selected out clone resources that possess significant application value. The results were as follows:1. There were significant differences among different Ginkgo clones. The yield of nuts had a positive correlation with the quantity of fruit-set and fruit-set rates. By path analysis, the contribution of tree characters to yield was different, the contribution from strong to weak was yield of seeds, quantities of ovule and fruit-set rates.2. 23 seed traits of Ginkgo clone were studied. The results showed that there were significant differences in the seed characters. The variances of seeds weight traits including nut ratio, weight of single nut, weight of single seed, weight of single kernel and shell thickness were great, while the variances of shape traits were low. Therefore, selection of clones by raising seed weight traits was more prone to be successful.3. The correlation analysis showed that weight of seed had a positive correlation with weight of single seed, seed length, seed thickness, nut length, nut width, nut thickness, kernel length, kernel width, kernel thickness and weight of kernel. The average weight of round nut was bigger than rectangle nut. The nut shape index had a positive correlation with nut length, stem length and seed shape index.The nut ratio had a positive correlation with seed width, weight of seed, pericarp thickness and shell thickness. Selecting great nut thickness was favorable to selecting clones of great kernel ratio.4. Based on principle component analysis and the cluster analysis method, the Ginkgo clones for production of nuts were divided into three classes. The results of classification by principle analysis method differed greatly from those by traditional method.5. For the chemical component of nuts, amylum> dissolubility sugar >protein>fat> flavones>lactone. For mineral nutrition, N>K>P>Mg>Ca. There were significant differences in chemical component of Ginkgo seeds. The difference in coefficient variation among chemical component was significant. The first 8 characters based on coefficient of variation were phosphorus, fat, nitrogen, dissolubility sugar, calcium, amylase, flavones, protein.Therefore, selecting the expected clones by these eight traits would gain better effect.6. Based on correlation analysis of nut shape traits and chemical component of Ginkgo seeds, the shell thickness had a positive correlation with dissolubility sugar, while had a negative correlation with nitrogen. The nut shape index and nut length had a negative correlation with fat.The ratio of nut width to thickness had a negative correlation with magnesium.7. Selecting out 14 high-yielding clones, 11clones with high weight of single nut, 16 clones with high medicine quality through clustering analysis method.8. Selecting out the first 10 clones for different use on indexes (weight of single seed, weight of single nut, nut ratio, kernel ratio and Chemical component) respectively.