铝胁迫对白芨光合与生理特性的影响

Effects of Aluminum Stress on Photosynthesis and Physiological Characteristics of Bletilla striata

采用盆栽白芨苗喷施不同浓度氯化铝溶液模拟Al^(3+)胁迫,在0(CK)、400μmol/L(T_(1))、600μmol/L(T_(2))、800μmol/L(T_(3))、1000μmol/L(T4)浓度处理下,分别以喷后3、5、7、9、11 d测定白芨叶片的各项生理指标和光合指标。结果表明,随Al^(3+)浓度的增加及铝胁迫时间的延长,丙二醛(MDA)含量显著上升,可溶性糖含量呈现先增后降,脯氨酸含量先升高后降低,SOD和POD活性均先升高后降低,2种酶活性都在Al^(3+)浓度为600μmol/L时达到最大值;铝胁迫处理导致白芨胞间CO_(2)浓度升高、气孔导度下降、净光合速率下降、蒸腾速率下降。白芨对铝毒有一定的抗性,但铝胁迫浓度越高,抑制作用越强,白芨的铝胁迫阈值为600μmol/L,当Al^(3+)浓度大于600μmol/L时会对白芨植株产生伤害。

Potted Bletilla striata seedlings sprayed with different concentrations of aluminum chloride solution to simulate Al^(3+)stress,under 0(CK),400μmol/L(T_(1)),600μmol/L(T_(2)),800μmol/L(T_(3))and 1000μmol/L(T4)concentration treatments,the physiological indexes and photosynthetic indexes of the leaves of Bletilla striata were measured at 3,5,7,9 and 11 days after spraying.The results showed that with the increase of Al^(3+)concentration and the prolongation of aluminum stress time,the content of malondialdehyde(MDA)increased significantly,and the content of soluble sugar increased first and then decreased,and the proline content increased first and then decreased,SOD and POD activity both first increased and then decreased,the enzyme activity of the two enzymes reached the maximum when the Al^(3+)concentration was 600μmol/L;the aluminum stress treatment resulted in an increase in the intercellular CO_(2) concentration of Bletilla striata,a decrease in stoma⁃tal conductance,a decrease in the net photosynthetic rate,and a decrease in the transpiration rate.Bletilla striata had certain resistance to alu⁃minum toxicity,but the higher the concentration of aluminum stress,the stronger the inhibitory effect,the aluminum stress threshold of Bletilla striata was 600μmol/L.When the concentration of Al^(3+)was greater than 600μmol/L,Bletilla striata plants would be damaged.