不同沙土配比对约书亚树幼苗生理特征的影响  

Physiological Characteristics of Yucca brevifolia Seedlings at Different Ratios of Sand to Soil

作　　者：刘力宁[1] 满秀玲[1] 唐中华[1] 李奕[1] 曲弨琪[1] 段亮亮[1] 

机构地区：[1]东北林业大学,哈尔滨150040

出　　处：《东北林业大学学报》2012年第7期25-29,共5页Journal of Northeast Forestry University

基　　金：国家林业局"948"项目(2009-4-18)资助

摘　　要：为了确定适宜培育约书亚树幼苗的沙土配比条件,以获得更适应恶劣、干旱环境的壮苗,在温室环境下,利用人工配比栽培土壤培育约书亚树幼苗,并利用LI—6400型光合仪测定2年生幼苗的净光合速率(Pn)、蒸腾速率(Tr)及其环境因子,同时测定幼苗体内渗透调节物质及酶活性指标,研究不同沙土配比对约书亚树幼苗生理特征的影响。结果表明:不同沙土配比对约书亚树幼苗的光合作用及渗透调节物质影响显著,但对幼苗抗氧化酶活性的影响不大。随着土壤环境的旱化,幼苗净光合速率降低,水分利用效率升高。较其它处理,沙土配比为5∶5左右的幼苗水分利用率最高(7.366μmol·m-2·s-1),该处理幼苗体内脯氨酸的质量分数(4.886μg·g-1)及可溶性蛋白质的质量分数(15.554 mg·g-1)均较高,分别为最低值的2.8、1.2倍。除抗氧化酶CAT活性随配比土壤中沙量的增加呈递减趋势外,SOD、POD、APX、GR活性差异不显著。An experiment was conducted to investigate the effects of different ratios of sand to soil on physiological characteristics of 2-year-old potted Yucca brevifolia seedlings in order to obtain strong seedlings which are more adaptive to dry environment. The seedlings were treated under different ratios of sand to soil （9 ： 1,7 ： 3, 5 ： 5, 3 ： 7 and 1 ： 9）. Net photosynthetic rate, transpiration rate, water use efficiency and environmental factor of Y. brevifolia seedlings under the condition of green- house were determined by LI-COR 6400 portable photosynthesis system four months after treatment. In addition, the osmotic adjustment substances and antioxidant enzyme activities were determined. Results show that different ratios of sand to soil have obvious effect on the photosynthesis and osmotic adjustment substances of Y. brevifolia seedlings, but exert little effect on the antioxidant activity of the seedlings. With increasing drought stress of soil, the net photosynthetic rate of the seed- lings decreased, while the water use efficiency increased. Compared with other treatments, the water use efficiency of the seedlings was highest （7. 366μmol · m^-2 · s^-1 ） at the ratio of 5 ： 5, and the contents of preline （4. 886mg·g^-1） and soluble protein （ 15. 554 mg·g^-1 ） of the seedlings became higher after the treatment, which were 2.8 times and 1.2 times of the minimum, respectively. No obvious differences in the activities of SOD, POD, APX and GR were observed, except the activity of antioxidant CAT which exhibited a descending trend with increasing ratio of sand to soil.

关 键 词：约书亚树 沙土配比 光合特性 抗氧化酶 脯氨酸 

分 类 号：S718.43[农业科学—林学]