摘要
为探究西瓜幼苗的耐盐机制和对NaCl胁迫的忍受范围,采用水培试验研究了0、20、70、120、170 mmol/L共5个水平的NaCl浓度对西瓜幼苗叶绿素荧光、光合特性、渗透调节、根系活力及保护酶活性的影响。结果表明,在NaCl浓度0~20 mmol/L范围内,西瓜幼苗叶绿素荧光、净光合速率、脯氨酸含量、可溶性糖含量、根系活力及超氧化物歧化酶活性与对照间差异均不显著;在70~170 mmol/L范围内,随盐胁迫强度的增强,西瓜幼苗叶片Fo逐渐增加,Fm、φPSⅡ和qP呈现逐渐降低的变化规律,且与对照间差异极显著;随着盐胁迫强度的增加,净光合速率、气孔导度和蒸腾速率呈降低趋势,其中,净光合速率在NaCl浓度170 mmol/L时最低,较对照降低56.95%,胞间CO2浓度与净光合速率呈现负相关关系;在0~170 mmol/L范围内,脯氨酸和可溶性糖含量逐渐升高,而根系活力和超氧化物歧化酶活性呈现先升高后降低的单峰变化规律。在NaCl浓度0~20 mmol/L范围内,盐胁迫对西瓜幼苗生理特性的影响不显著,在这一胁迫强度范围内西瓜幼苗可以正常生长,当NaCl浓度达到70 mmol/L及以上时,西瓜幼苗因受逆境伤害而不能正常生长。
To explore the salt tolerance mechanism of watermelon seedlings and the tolerance range of NaCl stress,the effects of 5 levels of NaCl(0,20,70,120,170 mmol/L)on chlorophyll fluorescence,photosynthetic characteristics,osmotic adjustment,root activity and protective enzyme activity of watermelon seedlings were studied by hydroponic experiment.The results showed that there were no significant differences in chlorophyll fluorescence,net photosynthetic rate,proline content,soluble sugar content,root activity and superoxide dismutase(SOD)activity between watermelon seedlings and the control in the range of 0-20 mmol/L NaCl concentration.In the range of 70-170 mmol/L NaCl concentration,with the increase of salt stress,Fo increased,Fm,φPSⅡand qP decreased gradually,and the difference was very significant.With the increase of salt stress,the net photosynthetic rate,stomatal conductance and transpiration rate decreased and the net photosynthetic rate was the lowest at 170 mmol/L NaCl concentration,which was 56.95%lower than that of the control,and the intercellular CO2 concentration was negatively correlated with the net photosynthetic rate.In the range of 0-170 mmol/L NaCl concentration,the contents of proline and soluble sugar increased gradually,while the root activity and SOD activity increased first and then decreased.In a word,the effect of salt stress on physiological characteristics of watermelon seedlings was not significant in the range of 0-20 mmol/L NaCl concentration.In this range,watermelon seedlings could grow normally.When NaCl concentration reached 70 mmol/L or above,watermelon seedlings could not normally grow due to stress damage.
作者
王中玉
逯昀
陈昆
WANG Zhongyu;LU Yun;CHEN Kun(Suixian Agricultural and Rural Bureau,Suixian 476000,China;Shangqiu Vocational and Technical College,Shangqiu 476000,China;Shangqiu Academy of Agriculture and Forestry Sciences,Shangqiu 476000,China)
出处
《山西农业科学》
2020年第12期1909-1912,共4页
Journal of Shanxi Agricultural Sciences
关键词
西瓜
盐胁迫
水培
叶绿素荧光
光合特性
渗透调节
保护酶
watermelon
salt stress
hydroponics
chlorophyll fluorescence
photosynthetic characteristics
osmoregulation
protective enzymes
