闽楠幼苗对光照的生态适应性

为了探明闽楠幼苗对光照的生态适应性,寻找最适宜闽楠幼苗生长的光照环境。以一年生闽楠幼苗为材料进行盆栽试验,分析不同光照环境(全光照以及全光照的85%、70%、55%、40%和25%)处理3个月后其生长及生理生化指标变化。结果表明:强光对闽楠幼苗生长产生胁迫,全光照(100%)条件下,幼苗生长及生理生化均受到明显抑制,丙二醛、脯氨酸含量以及质膜相对透性最大,而超氧化物歧化酶(SOD)活性最小;低光环境对于闽楠幼苗有机物质累积和光合、蒸腾等生理过程短时间内表现促进作用,但其生化指标对极弱光照响应很快,25%极弱光照强度下,其生长、生物量积累和光合、蒸腾生理指标均最大,丙二醛含量、质膜透性仅次于100%光强。综合苗木生长及生理指标考虑,闽楠苗期适宜的光照环境为全光照的40%~55%。

Ecological Adaptability of Phoebe bournei Seedlings to Photo-environment

The physiology and biochemical indexes and growth of P.bournei seedlings with one year old planted in pots under different light environments of 100％ light,85％ light,70％ light,55％ light,40％ light and 25％ light for three months were analyzed to explore ecological adaptability of P.bournei seedlings to photo-environment and search the optimum light enviroment for growth of P.bournei seedlings.Results:100％ light inhibits physiology and biochemical indexes and growth of P.bournei seedlings significantly.The leaf MDA and proline content and relative plasma membrane permeability of P.bournei seedlings under 100％ light are the highest but its SOD activity is the minimum.Low light promotes organic matter accumulation and the physiological process of photosynthetic and transpiration in a short time but the biochemical index responds to very lower light quickly.The growth,biomass accumulation,photosynthetic and transpiration indexes of P.bournei seedlings under 25％ light are the maximum but the MDA content and plasma membrane permeability are second only to 100％ light.The suitable light enviroment of P.bournei seedlings is 40％ ～ 55％ of full illumination and physiological indexes of P.bournei seedlings comprehensively.