| Castanopsis fargesii Franch is the dominant tree species in subtropical evergreen broad-leaved forests. This study is based on the research of different provenances seed germination, seedling and seedling substrate treatments on photosynthetic characteristics, obtaining the seedling container storage and the key technology of C. fargesii seed, providing technical support for the future of C. fargesii seedlings. According to the analysis about the photosynthetic characteristics of different C. fargesii seedlings, we preliminarily screen out the better performance at the seedling stage of 4 provenances from Huitong, Wuyishan,Shangyou and Longnan. The purpose summarize the Castanopsis fargesii seed storage and germination technology, provide technical support for the cultivation of seedlings of Castanopsis fargesi. Also analysis and 11 silk chestnut Castanopsis species source photosynthetic characteristic parameters, for the screening of Castanopsis fargesii seed sources to provide technical support, to provide theoretical basis for the community succession and ecosystem restoration and reconstruction of evergreen broad-leaved forest. The main conclusions are as follows:1. There are significant differences in the thousand-grain weight and germination rate of different C.fargesii seeds. The thousand-grain weight of C. fargesii seed is 532.51 g on average,the maximum value is Qingyuan in Zhejiang provenance with 578.60 g, which is the 1.14 times of the minimum in Xunwu. The germination rate without pregermination is 46.3%-93.8% and the provenance of Huitong has the highest germination rate, reaching 93.8%, which is 2 times of the provenance of Jing dezhen.2. The germination rate of C. fargesii seeds which from Longnan of Jiangxi provenance will be 95% if the seeds are soaked with cold water for 24 h before germinating, which is 5.6% higher than those seeds did not. It can also shorten the germination period for 3-4d. The height growth of C. fargesii seedlings can be divided into three stages in the first year: the seedlings unearthed period is May to June, the mushroom period is July to September, and the slow-growth period is September to November. In the second year, seedlings will grow rapidly from March to September, while grow slowly from September to November.3. Study the seedlings of C. fargesii(A: Yellow subsoil; B: humus; C: humus: Yellow subsoil = 1:1; D: humus yellow soil: sand = 1:1:1; E: Yellow subsoil: burned soil = 3:1; F: Perlite: peat = 1:1) about the varieties, net photosynthetic rate, growth and biomass. The results show that seedlings of C. fargesii have marked differences in the varieties, net photosynthetic rate, growth and biomass. We use perlite: peat = 1: 1 to cultivate the seedlings for two years,then the net photosynthetic capacity, the height, the diameter growth and the biomass of seedlings is 4.78 μmol CO2.m-2s-1,35 cm,3.4cm and 6.05 g.As the result is better than any other treatments, we regard this method as a more suitable method for the cultivation of seedlings.4. Determine 11 different provenances of C. fargesii of photosynthetic rate. The results show that the diurnal dynamics of photosynthetic of C. fargesii presents the“ two peak ”curve, and the minimum net photosynthetic rate appeared at 7:00 with only 0.4μmolm-2s-1.Then its photosynthetic rate increased gradually, reaching the maximum at 11:00 am with the first peak of 3.2μmolm-2s-1.Later the photosynthetic rate showed a downward trend with a "siesta" phenomenon and even appeared a trough of wave at 14:00. At 15:00, the photosynthetic rate appeared the second peak with 2.8μmolm-2s-1, and then the photosynthetic rate decreased gradually.5. Determine 11 different provenances of C. fargesii of net photosynthetic rate. The results show that seedlings of C. fargesii that from different provenances still have significant difference in the maximum net photosynthetic rate. The maximum net photosynthetic rate of Huitong, Wuyishan, Shangyou and Longnan is 7.57μmol m-2s-1, 7.31μmol m-2s-1, 7.02μmol m-2s-1 and 5.82 μmol m-2s-1; the light saturation point of the four cities is 1627μmol m-2s-1,1484μmol m-2s-1,1598μmol m-2s-1 and 1553 μmol m-2s-1. Therefore, from the perspective of photosynthetic characteristics, we can find that the provenances of the four cities possess a wide scope and high ability to adapt the light environment and also have a very good photosynthetic potential. |
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