光强对雾培杉木幼苗生长及生理特征的影响

Effects of Light Intensity on the Growth and Physiological Characteristics of Chinese Fir Seedling under Aeroponics Environment

为研究气雾栽培环境下 LED 白光不同光强对杉木幼苗生长、形态及生理特征的影响,本试验采用波峰为 453nm 的白光光源,设置了 35、25、15、10 和 3 μmol m^-2 s^-1 5 个光强梯度处理,测定 1 年生杉木幼苗的生长、生物量分配和酶活性等特征。结果表明,气雾栽培环境下中高光强处理能明显促进杉木幼苗高的生长,但不同光强处理地径无显著差异;随着光强的减弱,杉木幼苗根长、根表面积和根体积的生长量呈降低趋势;根生物量比和光合与非光合组织生物量比均随着光强的减弱而递减,叶生物量比在光强为 25 μmol m^-2 s^-1的光强处理下最高,茎生物量比和根冠比无显著差异;随着光强的减弱,SOD 活性呈现先上升后下降的趋势,POD 活性随着光强的减弱而上升,MDA含量呈现出先下降后上升的趋势。因此,气雾栽培环境下白光中高光强处理最有利于杉木幼苗生长。

In order to explore the effects of LED White light intensity on growth, morphology and physiological indexes of Chinese fir seedlings under aeroponics environment, The LED white light was composed with peak at 453 nm, treatments with 5 different light intensity: 35, 25, 15, 10 and 3 μmol m^-2 s^-1, the growth, biomass allocation and enzyme activity of one-year-old Chinese fir seedlings under aeroponics environment. The results showed that the medium and high light intensity can significantly promote the growth of Chinese fir seedlings in aeroponics environment, but there was no significant difference in diameter between different light intensity treatments. With the light intensity decreased, the root length, root area and root volume of Chinese fir seedlings decreased. The root biomass ratio and photosynthesis non-photosynthesis biomass ratio decreased with the decrease of light intensity, leaf biomass ratio was the highest under 25 μmol m^-2 s^-1 light intensity, there was no significant difference between stem biomass and the root shoot ratio. SOD presented a trend of first rised and then declined, POD activity increases with the decrease of light intensity, MDA presented a trend that decreased first and then rised. Therefore, white light treatment with medium and high light intensity was the most beneficial to the growth of Chinese fir seedlings under aeroponics environment.