| Melia azedarach Linn is one of native tree species widely distributed in china with fast growing and multifunctional and comprehensive utilization .It will have wider application prospects and development value. There are many advantages in the insecticides which were made of extracts from M. azedarach Linn, such as high efficiency on the pests, safety to non-target biology, easy decomposition, no residue, no pollution to environment and uneasily make the pests resistance. But now the tress species of M. azedarach Linn is very dispersed and seriously destructed, and far away from the industrialization requirements of their utilization. So the research of selection and breeding for improved variety, cultivation technology and its construction of forests of fast-growing and high-yield will be one of research focus.This paper selected some plus trees of high contents of toosendanin based on the investigation of resources of M. azedarach Linn in Fujian Province. In this study, growth situation of young forests, different afforestation density experiment and cuttage technology were carried out, by introducing different provenances from major distribution areas of M. azedarach Linn. The contents variation of nutrient elements and chlorophyll from different provenances were also analysed. And its RAPD molecular maker and its gentic diversity were studied. The main results were as follows:1.By orthogonal experiment of L9 (34) optimizing condition was gotten. The results showed that: the concentration of ethanol is the first key factor of extraction, and immersion time is the second key factor of extraction. The results showed that the simplest extraction method was that added 45 ml alcohol of 95% to the sample of 5 g , then immersed at temperature of 50℃for 60 minutes with 3 repetitions.2. Analysis of correlated factors to between the basic climate factor of the areas of primary selection plus trees and the content of toosendanin showed that longitude and altitude affect the content of toosendanin most. Altitude was beneficial to the accumulation of toosendanin. With the increasing of altitude, the content of toosendanin of M. azedarach Linn trended to increase. Main variations of the trunk character of M. azedarach Linn were tree height and crown.3. Based on the cluster analysis, according to the content of toosendanin 81 primary election plus trees of M. azedarach Linn in Fujian Province can be divided into 4 types.Cluster I was extremely high content provenance which included No.11.And No. 8,23,27,46,49,60,66 belonged to cluster II which were high content provenances. No. 4,5,6,7,9,13,15,16,17,18,20,21,22,24,25,29,33,34,35,36,37,38,39,40,42,45,47,48,50, 51,54,55,56,57,58,59,61,62,63,69,70,71,72 were the members of cluster III, they were middle content provenances. Cluster IV included No. 1,2,3,12,14,19,26,28,30,31,41,43,4 4,52,53,64,65,67,68,73,74,75,76,77,78,79,80,81 which were low content provenances. A ccording to the point system of comprehensive properties, 81 primary election trees a re classified to 4 types respectively for " extremely high " , "high ","middle"," low ".There are 39 officinal type is selected to be plus trees among the first two kinds. The selecting rate is 48.15%.4. Through ladder experiments, the reliable RAPD analysis system was established. The results showed that the bands were clear in the following conditions: the genomic DNA concentration was 60 ng, Mg2+ concentration was 3.0 mmol·L-1, dNTP concentration was 0.25 mmol·L-1, primer concentration was 0.30μmol·L-1. Taq DNA concentration was 1 U. The total reaction volume was 20μL. RAPD program was 2 minutes at 94℃for predenaturation, then 38 cycles of 30 seconds at 94℃for denaturation , of 1 min at 37℃for annealing , of 80 seconds at 72℃for extension , extension at 72℃for 8 min, finally soaked at 4℃.5. Based on 20 primers and optimization of RAPD system for M. azedarach Linn, 15 samples from different provenances were analyzed by RAPD technique. 193 clear and repeat sites were totally detected by 20 primers. The polymorphic degree was up to 97.9%.On the average, one primer produced 9.7 sites.6. UPGMA cluster analysis was carried out basing on the RAPD data. The 15 accessions of M. azedarach Linn were divided into 4 groups at the level of D=0.60.Group I included NO.1,3,9,6,11,12,13,15,14,10 which are from Mianyang Sichuan, Baoshan Yuannan, Yongtai Fuzhou, Liuyang Hunan, Youxi Fujian,Jianou Fujian, Changshan Fuzhou, Yanping Fujian. Group II involved NO.2, 4, 7 from Jinhua Zhejiang, Changjiang Hainan, Longquan Guangxi. Group III included No.8 from Lushan Jiangxi and group IV included No.5 from Nanning Guangxi. It was found that Group I was situated firstly which were from Yanping, Jianou, Changshan, Yongtai, Youxi separately.And it was consistent with the devision of geographical area. It meaned the provenance origins from the same province approximated to same. But the 15 accessions can be divided into 2 kinds at the level of 0.72, and the first kind included group I, group II and group III;the second kind included group IV. The result manifests that the M. azedarach Linn can roughly divided into two populations at the level of molecule DNA.7. There were great differences in the content of nutrient elements of different provenances. The average content of total nitrogen of branch was 7.178 g·kg-1. The average content of total phosphorus of branch was 0.826 g·kg-1. The average content of total potassium of branch was 2.511 g·kg-1. The average content of total nitrogen of leaf was 16.067 g·kg-1. The average content of total phosphorus of leaf was 1.165 g·kg-1. The average content of total potassium of leaf was 2.540 g·kg-1, respectively. The content of total nutrient elements of branch and leaf arranged sequentially large to small: N>K>P. There were obvious differences in the ability of absorption and utilizting nutrient elements of different provenances.Correlation analysis between the content of nutrient elements of branch and leaf of different provenances and the geographical factors and climate factors of different provenances were studied. The results showed that there were not close relationships among them.8. There were great difference in the ability of photosynthesis of different provenances. Based on the content of chlorophyll of mature leaf, results of variance analysis showed that, there were significant difference or extremely significant difference of the content of chlorophyll of different provenances. The content of chlorophyll a were between 0.8642 and 5.4768 mg·g-1·FW, with an average of 2.7444 mg·g-1·FW. The contents of chlorophyll b were between 0.3574 and 3.5528 mg·g-1·FW, with an average of 1.2351 mg·g-1·FW. And the content of total chlorophyll were between 1.2266 and 8.9969 mg·g-1·FW, with an average of 3.9725 mg·g-1·FW.9. From orthodoxy analyze of cuttage experiment for M. azedarach Linn, the best theory cuttage way was A2B1C1, that was using one year of cuttage with IBA 300 mg·L-1 to soak in 2 hours.The effect of cuttage in the mixture of red soil and riversand was the best of the three cuttage medium: riversand, red soil, mixture of riversand and red soil. The cuttage effect of different season arranged sequentially from good to bad: spring (March), autumn (October) summer (July).10. Based on the analysis of 4-year-old growth traits from 5 provenances, the geographic variations of M. azedarach Linn were studied with statistical methods, such as variance and correlation analysis. The results showed that there were negative correlations between height, diameter, volume and latitude, but they were positively correlated with longitude. In addition, precipitation and temperature were important effect factors to M. azedarach Linn growth. The biomasses of single tree and its distribution of tissues of 5 provenances arranged sequentially from great to small: bole, root, branch, and leaf. There were rich variations within M.azedarach Linn resources, the variation coefficients of height, diameter, and crown diameter were 35.29%, 36.89%, and 45.75%. In a word the comprehensive growth of 5 provenances in the induction area arranged sequentially from good to bad: Nanchang Jiangxi, Changsha Hunan, Ninghai Zhejiang, Zhengjiang Jiangsu, Xiangyang Hubei.11.3 kinds of afforestation density of M. azedarach Linn of young forests varied from 1200, 1650, 2500 trees·hm-2 were established to research their afforestation effects. Results showed that, the growth of height, diameter, and crown with volume of 1650 trees·hm-2 was the fast which survival rate and preservation rate were both more than 90%. There were great differences in average individual biomass among different density. The average individual biomass of 1650 trees·hm-2 was the biggest, which fresh weight was 10.160 kg and dry weight was 3.854 kg. The average individual biomass of 1200 trees·hm-2 was the smallest, which fresh weight was only 8.630 kg and dry weight was 3.504 kg. In a word, the afforestation effect of 1650 trees·hm-2 among the three afforestation density was the best. |
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