不同瑞典能源柳无性系对干旱胁迫的生理响应

以瑞典能源柳无性系2、4、C、E的一年生盆栽扦插苗为材料,采用土壤持续强化干旱胁迫实验,系统测定不同胁迫阶段叶片超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)活性,以及丙二醛(MDA)、可溶性蛋白含量和株高净生长量,并采用隶属函数模型综合评定了不同能源柳无性系的耐旱性。结果表明:(1)各能源柳无性系叶片的保护酶活性随干旱胁迫的加剧均呈现先增后降趋势:土壤水分含量>11.4%时,SOD、POD和CAT活性均呈增长趋势,三者协同作用;土壤水分含量<11.4%,能源柳无性系2、4的CAT和POD活性显著降低,细胞膜受损。(2)各无性系MDA含量随干旱胁迫的加剧呈增长趋势,土壤含水量降至11.4%时,MDA含量增长显著,其中能源柳无性系4变化最为剧烈。(3)各无性系可溶性蛋白含量随干旱胁迫的持续而增加,但当土壤含水量低于8.1%时有所下降。(4)各能源柳无性系胁迫阶段株高净生长量随干旱胁迫的加剧而降低。(5)隶属函数综合分析发现,4个无性系耐旱潜力表现为能源柳C>能源柳E>能源柳2>能源柳4。

Physiological Responses of Different Energy Willow Clones under Drought Stress

We studied on the drought tolerance of four different energy willow clones(Salix dasyclados,S.mesu,S.fragilis,S.viminalis).Using potted 1-year old seedlings of the four different clones,we conducted a soil-drought controlled experiment and measured the changes of SOD activity,POD activity,CAT activity,MDA content,protein content and relative growth of height.The results revealed the following consequences.(1)With the decrease of soil water content,the protective enzyme activities of 4 energy willow clones improved until the soil water content was below the level of 11.4%.This phenomenon showed that SOD,CAT and POD acted synergistically on assuring the plants’ regular growth.While the water content fall below 11.4%,both S.dasyclados and S.mesu CAT and POD activities significantly reduced.It indicated that under this water condition the seedlings suffer from the drought stress.(2)The MDA contents of all the four clones increased along with the drought stress enhancing.The growth was remarkable when the water content fall to 11.4%.The change of S.mesu is especially notable.(3)The content of protein was increasing as the soil becoming more and more arid.But it turned to decrease as the water content was fewer than 8.1%.(4)The relative growth of height of all the energy willow clones reduced while the drought condition increased;(5)According to fuzzy synthetic evaluation of the activities of three protective enzymes,MDA content and protein content to water stress in leaves,the drought-tolerance of the four energy willow clones decreased in the following order:S.fragilis>S.viminalis>S.dasyclados>S.mesu.