干旱胁迫对红锥生理生化指标的影响

Effects of Drought Stress on Physiological and Biochemical Properties in Castanopsis hystix

为了评估红锥Castanopsis hystrix的耐旱性,实验以福建10个半同胞家系1.5年生红锥苗为研究对象,采用控制水分盆栽的方式,研究不同基质含水量(含水量分别为15%,30%,50%,75%)持续100 d过程中红锥半同胞家系苗过氧化物酶(POD)、超氧化物歧化酶(SOD)、丙二醛(MDA)、叶绿素含量、类胡萝卜素含量、电导率(Rcond)、叶片含水量(RWC)的变化。结果表明,整个试验阶段家系间POD活性及叶绿素a(C_a)、叶绿素b(C_b)、总叶绿素(C_t)、类胡萝卜素(C_(xc))、总色素(C_(tp))含量差异显著(P<0.05),干旱主要通过影响叶片色素的变化进而影响红锥的生长;叶绿素中以叶绿素a为主;叶片能够较长时间维持较高的相对含水量,但基质含水量15%持续100 d时6个家系苗木因干旱胁迫全部死亡,而基质含水量50%以上时,红锥细胞膜受损程度要小得多;基质适度干旱有利于高根冠比的形成;半同胞家系3、家系8、家系9在参试半同胞家系中为综合表现较佳的半同胞家系。总的来说红锥是比较抗旱的树种,但需进一步开展试验。

Experiments were conducted on different water contents(15%,30%,50%and 75%)of media for potted cultivation of 10 half-sib families of Castanopsis hystix seedlings from Fujian Province for 100 days.Changes in POD,SOD,MDA,chlorophyll content,carotenoid content,electric conductivity,and leaf moisture content were measured in order to evaluate drought tolerance.The results showed that there were significant differences among tested half-sib families in POD activity and contents of chlorophyll a and chlorophyll b(Ca and Cb),total chlorophyll(Ct),carotenoids(Cxc)and total pigment(Ctp),and drought stress had an effect on growth by influencing leaf pigments.Chlorophyll a had a higher content than chlorophyll b.Seedlings of six families treated with a medium moisture content of 15%died 100 days later.The experiment indicated that tested C.hystixcan families were resistant to drought stress.