| Taxus wallichiana var. mairei is the most widely distributed plants of Taxus in China, due to its relative lack of natural germplasm resources and have been greatly damaged by human, and it have been listed as rare and endangered plants. Not only can extract the good anti-cancer drug paclitaxel from it, but also its timber is hard, and wood quality is great.So it can be preciousness commercial tree species. With the rapid development of society, the wood products that people pursuit is not limited in the fast-growing timber, and it will greatly turn to the high quality of valuable timber. Thus, this study used Taxus wallichiana var.mairei provenances and the excellent families from different provenances to carry out the work about the selection of excellent provenances and familes, and the genetic variation of their growth and phenotype, and variation of the family photosynthetic physiology. The results were as follows.1. Genetic variation of different tree age T. wallichiana var. mairei provenances: Most of the growth characteristics of 24 provenances have significant effects on provenance, site, and the interaction effect of provenance site. The variable coefficient of 10 years height, diameter at breast height(DBH), crown diameter of two test points, across provenances were 6.58%,15.14%,11.18% and 9.17%,17.18%,17.14%. The result of site effect indicated that 10 years height and DBH of provenances in Longquan were higher 28.77% and 10.57% than provenances in Anji, respectively. Correlation indicated that the correlation coefficientamong 7-year-old height and 10-year-old height of provenance from Anji and Longquanwere 0.709 and 0.744, respectively. And they were bigger than the correlation coefficient 0.479 and 0.649 among 4-year-old height and 10-year-old height of provenance from Anji and Longquan. It indicated that the age was bigger the select effect was better.We finally selected 7 and 3 excellent provenances from Longquan and Anji by means of independent culling method based on the 10 years height and DBH and 7-10 years growth of height and DBH, respectively.2. The family variation of T. wallichiana var. mairei in multi-point test found that: Based on the study of growth variation of T. wallichiana var. mairei provenance, the result of variation of T. wallichiana var. mairei families!s growth showed that the height, ground diameter and height growth rhythm parameters among the families, sites, and site families were significantly different. The maximum height of families in Fenyi of Jiangxi, Jing shan of Hubei, Chunan and Longquan were 76.20%, 52.98%, 55.42% and 78.10% higher than their minimum height, respectively. For ground diameter, the maximum values were 126.67%, 23.68%, 37.02% and 26.48% higher than the minimum ones, respectively. The heritability of traits was between 0.80 and 0.97. It showed that family early selection has certain reliability.But the significant interaction effect between family and site showed that part of the families growth was influenced strongly by environment, and their genetic stability were weak.In additional, the correlation analysis indicated that there were different relationships between height and parameters of growth rhythm at the different test points. It was a negative correlation between height and linear growth rate in Fenyi, while they were positively related in Longquan. Based on seedling height, we chose 7 good performed families from each of the four test points. Both of JO11 and the SY06 were selected from the four test points so that they had a higher genetic stability, and could be planted in more places for promotion.3. Variation of growth and photosynthetic physiological characteristics on T. wallichiana var. mairei families from different provenances: Based on the study of family growth varuation, we studied the photosynthetic physiological variation on families. The result showed that it was not significantly different on growth, content of chlorophyll and net photosynthetic rate of 2 years seedlings among provenances, but it was significantly different among families. In 20 families, the maximum height and ground diameter of families were higher 52.99% and 29.63% than the minimum value, respectively; The maximum of "maximum growth rate#(MGR), " linear growth rate#(LGR), "total linear growth#(TLG) and " day of linear growth#(LGD) of families were higher than the minimum values by 60%, 62%, 64% and 23%, respectively; And the maximum of net photosynthetic rate in families were 2.19 times as faster as the minimum values of families. The above showed that T. wallichiana var.mairei had rich genetic variation among families. The result of correlation analysis showed that there was significantly positive correlation between height and MGR, LGR, TLG, net photosynthetic rate or content of chlorophyll, but there was not significantly correlation between height and LGD. It indicated that the growth of families was mainly affected by growth rate. According to the result of clustering which was based on growth, growth rhythm parameters, net photosynthetic rate and content of chlorophyll, the 20 families were divided to 4 groups. The first group of families had worst growth, lowest growth rhythm parameters and net photosynthetic rate were the lowest; The second group had better growth, and its net photosynthetic rate was higher, but the content of chlorophyll lower; The third group's growth rate and net photosynthetic rate were worse, however its content of chlorophyll was higher; The indexes of the last group were the best, and it had great growth potential. Therefore, LQ09, LQ11, FY21, FY26, MX12 and MX18 from last group were preliminary selected as excellent families for promotion. |
PDF Full Text Request