| As an excellent native hardwood species growing in subtropical regions, Castanopsis tibetana is a valuable timber species with broad prospect. In this paper, four physiological indexes were tested, including seed morphology, quality, seedling growth traits and photosynthetic characteristics and comparing and analyzing the differences of seed and seedling among different provenances. The seeds of Castanopsis tibetana in Hubei Enshi, Fujian Jian’ou, Hunan Liuyang, sangzhi and Yongshun respectively were collected. Due to the present sitiation of its varieious ecotypes, less of nature growing area and low level well-bred. In the paper,the seeds and one-year-old seedling of different provenances and individual were studied as subjects to study the geographical variance of seed quality growth characteristics ,photosynthesis rate and so on. Aimed at choosing Castanopsis tibetana seedling with the features of grow-fast, productive and good adaptability. The variation of seeds of Castanopsis tibetana were founded on the research basement of configuration,seed quality,which would support the reference for seeds allocation. The superior provenances were selected which adapted to Hunan province, after evaluating comprehensively.At the meantime, the growth features of seedlings were mastered, which would support theory foundation for the management of seedling stage of Castanopsis tibetana,and would contribute to protect and utilize Castanopsis tibetana. The main results are as follows:1 There are significant differences among provenances about seed morphology indexes, including length, width, height and grain weight. The distribution of indexes about different provenances are as follows:grain weight is between 344.87g and 442.44g; seed moisture is between 39.29% and 46.01%, which is high, suggesting the seed is not suited to store; starch, as the main component of organic nutrients, is between 341.93 mg·g-1 and 385.35 mg·g-1; soluble sugar is between 20.99 mg-g’1 and 24.86 mg·g-1 and the protein is between 10.43 mg·g-1 and 17.38 mg·g-1 suggesting the nutritionl component is low and the nutritional value is in general. Afte rmoss wet storage, the nuesery germination rate and rapid determination of seed vigor are both high and consistent, suggesting the seed viability is high. The significant differences suggest that the geography and climate are important to seed quality.2 The slow-fast-slow growth rhythm of one-year seedling shows a S-shaped curve, complying with Logistics equation. The seedling grows slowly:the height of one-year seedling is between 14.84 cm and 19.77cm, the ground diameter is between 2.63mm and 4.07mm and the biomass of single plant is between 3.28g and 3.85g respectively. The root-stem ratio of different provenances suggests that the Castanopsis tibetana is not resistant to drought. This result is consistent with performance of seedling. The significant differences from height of seedling, growth of ground diameter, accumulation of biomass and root-stem ratio mean great potential from seedling selection of excellent provenance.3 The Pn diurnal variation of Castanopsis tibetana shows a bimodl curve in spring, summer and autumn and an unimodal curve in winter. The order of Pn daily average value in four seasons is summer> autumn> spring> winter. The order of LCP, LSP, AQY, Rd and Pnmax are all summer> autumn> spring> winter and the photosynthetic superiority is obvious in summer. Photosynthetic capacity of Castanopsis tibetana has some plasticity in physiology, being consistent with intolerant tree species.4 The geography and climate of different growing area not only affect the quality of Castanopsis tibetana seed directly, but also affect the growth of seedling through the effect of chlorophyll content and Pn. After comprehensive evaluation of different provenance, we determine that Hubei Enshi provenance is the most suitable provenance growing in Hunan and become an excellent provenance of rare hardwood species; Hunan Sangzhi provenance is the second excellent provenance. |
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