NaCl胁迫对5年生蜡梅生长及生理特性的影响

为探讨蜡梅对盐胁迫响应机制和耐盐性,利用盆栽5年生‘一品晚黄’蜡梅实生苗,进行质量分数分别为0、0.3%、0.6%、0.9%、1.2%的盐胁迫处理40 d,观测不同质量分数盐胁迫下蜡梅的生长、生理和叶绿素荧光参数等指标。结果表明:植株在低质量分数(0.3%)盐胁迫下存活率高,植株表观特征未受到显著影响,叶片组织含水量、相对电导率均变化不显著,丙二醛(MDA)质量摩尔浓度增加,并通过提高过氧化物酶(POD)、超氧化物歧化酶(SOD)活性和游离脯氨酸(Pro)质量分数、可溶性糖(SS)质量摩尔浓度、可溶性蛋白(SP)质量摩尔浓度来主动响应低盐胁迫;随盐胁迫程度的提高,植株出现叶片发黄焦枯、卷曲,根系减少,植株死亡等现象,生长量与盐质量分数间呈极显著负相关(P<0.01),相对电导率、MDA质量摩尔浓度持续升高,叶片组织含水量、各叶绿素荧光参数值显著降低。蜡梅对低盐胁迫有较强耐受能力,高质量分数盐胁迫对蜡梅的生长和生理有较强的毒害作用,生长受到严重抑制甚至死亡,同时筛选出叶片组织含水量、POD活性、MDA质量摩尔浓度、游离脯氨酸质量分数、可溶性糖质量摩尔浓度、最大光化学效率(F_v/F_m)、实际光合效率(Y_II)、电子传递速率(r_E,T,R)作为评价蜡梅耐盐性的主要生理指标。

Effects of NaCl Stress on the Growth and Physiological Characteristics of Five-year Chimonanthus praecox

In order to investigate the response mechanism and salt tolerance of Chimonanthus praecox to salt stress,five-year seedlings of C.praecox‘Yipin Wanhuang’were potted for 40 d under 0,0.3%,0.6%,0.9% and 1.2% salt stress.The growth,physiological and chlorophyll fluorescence parameters of C.praecox under different concentrations of salt stress were observed.The results showed that the survival rate of plants was high under low concentration(0.3%)salt stress,the phenomenal characteristics of plants were not significantly affected,the water content and relative conductivity of leaf tissue were not significantly changed,the content of malondialdehyde(MDA)increased,and the activities of peroxidase(POD),superoxide dismutase(SOD),free proline(Pro),soluble sugar(SS)and soluble protein(SP)were increased with the deepening of salt stress,and the plant appeared yellow,scorch,curl,root reduction,plant death and other phenomena.There was a very significantly negative correlation between the growth and salt concentration(P<0.01),the relative conductivity,MDA content continued to rise,and the leaf tissue water content,chlorophyll fluorescence parameter value decreased significantly.Therefore,C.praecox has a strong tolerance to low salt stress,high concentration of salt stress has a severe toxic effect on the growth and physiology of C.praecox,growth is severely inhibited or even died,and the leaf tissue water content,POD,MDA,Pro,SS,F_v/F_m,Y_II,r_E,T,R were used as the main physiological indexes to evaluate the salt tolerance of C.praecox.