干旱下白枪杆幼苗生物量及生理活性物质对钙添加的适应性调节  

Adaptive Regulation of Biomass and Physiologically Active Substances in Response toCalcium Addition in Fraxinus malacophylla Seedlings Under Drought

作　　者：茶晓飞 董琼[1] 段华超 郭焕仙 张梅 李燕燕 李世民 CHA Xiao-fei;DONG Qiong;DUAN Hua-chao;GUO Huan-xian;ZHANG Mei;LI Yan-yan;LI Shi-min(Key Laboratory for Resources Conservation and Utilization in the Southwest Mountainous Areas of China,Ministry of Education,Southwest Forestry University,Kunming 650224,Yunnan,China)

机构地区：[1]西南林业大学西南山地森林资源保育与利用教育部重点实验室,云南昆明650224

出　　处：《西北林学院学报》2023年第3期10-17,共8页Journal of Northwest Forestry University

基　　金：科技部国家重点研发子课题(2017YFD0601202);云南省教育厅科学研究基金项目(2021J0166)。

摘　　要：探究白枪杆幼苗对石漠化岩溶地区高钙干旱环境的适应调节机制,为白枪杆在石漠化地区推广造林、植被恢复提供重要理论依据。以1年生白枪杆实生苗为研究对象,采用双因素完全随机区组试验,因素1为干旱程度,设4个干旱梯度(正常水分、轻度干旱、中度干旱、重度干旱);因素2为外源CaCl_(2),浓度设0、25、50、75 mmol·L^(-1)4个水平。栽植6个月后,测定白枪杆幼苗生物量和渗透调节物质(游离脯氨酸、可溶性蛋白、可溶性糖)含量以及抗氧化酶(SOD、POD、CAT)活性。结果表明,1)干旱下添加外源钙能显著增加白枪杆幼苗茎、地下生物量、根茎分配比,减少叶生物量积累与分配比,根冠比降低。2)干旱时期,施加外源钙后白枪杆幼苗叶片MDA含量下降;添加25~50 mmol·L^(-1)钙能有效提高白枪杆叶片3种渗透调节离子(游离脯氨酸、可溶性蛋白、可溶性糖)含量,对可溶性糖、可溶性蛋白含量影响显著。3)干旱下添加钙能显著提高白枪杆幼苗SOD、CAT酶活性,对POD酶活性影响不显著。在干旱时期添加外源钙,能缓解干旱胁迫对白枪杆幼苗的损害并有效提高其抗旱能力。在轻度和中度干旱时期,白枪杆幼苗适应性较强;同期,施用25~50 mmol·L^(-1)外源钙,能够增强白枪杆幼苗生理抗旱能力。It is very important to explore the adaptive adjustment mechanism of Fraxinus malacophylla seedlings to high calcium and arid environment in rocky desertification karst areas.Through the research,the result will provide an important theoretical basis for afforestation and vegetation restoration in similar areas.The experiment was conducted on 1-year-old F.malacophylla seedlings in a two-factor completely randomized group test,with factor 1 being the degree of drought and four drought gradients(normal moisture,mild drought,moderate drought,and severe drought);factor 2 being the exogenous CaCl_(2)concentration and four levels of 0,25,50 and 75 mmol·L^(-1).Six months after planting,the biomass and osmoregulatory substance(free proline,soluble protein,soluble sugar)contents,as well as antioxidant enzyme(SOD,POD,CAT)activities,were measured in F.malacophylla seedlings.1)The addition of exogenous calcium significantly increased the stem and underground biomass and root to stem distribution ratio,decreased the leaf biomass accumulation and distribution ratio,and decreased the root to the crown ratio of the seedlings under drought.2)During drought,the MDA content of the seedling leaves decreased after exogenous calcium was applied;the addition of 25-50 mmol·L^(-1)calcium effectively increased the content of three osmoregulatory substances(free proline,soluble protein,and soluble sugar)in the leaves,and had significant effects on the contents of soluble sugar and soluble protein.3)Calcium addition under drought significantly increased the SOD and CAT enzyme activities of the seedlings,but had no significant effect on POD enzyme activity.Adding exogenous calcium during drought can alleviate the damage of drought stress on F.malacophylla seedlings and effectively improve their drought resistance.During the period of mild and moderate drought,the seedlings were more adaptable;during the same period,the application of 25-50 mmol·L^(-1)exogenous calcium enhanced the physiological drought resistance of the seedlings.

关 键 词：石漠化 旱钙胁迫 生长 渗透调节 抗氧化酶 

分 类 号：S718.43[农业科学—林学]