NaCl胁迫对不同倍性西瓜幼苗叶片叶绿素含量的影响

Effect of NaCl stress on the chlorophyll contents of watermelon seedling leaves with different ploidy

为探讨NaCl胁迫对不同倍性西瓜幼苗叶绿素含量的影响,用浓度为0、100、200、300、400 mmol·L-1的NaCl处理西瓜幼苗,95%(φ)乙醇提取叶片中的叶绿素,比较NaCl胁迫下不同倍性西瓜幼苗叶绿素含量的变化。结果表明,在低盐浓度下,西瓜幼苗叶片中的叶绿素含量随胁迫时间增加的变化较小。在NaCl浓度为100 mmol·L-1时,随着NaCl胁迫时间的增加,2x、3x、4x叶片中的叶绿素含量分别由33.4、33.5、32.3 mg·g-1降为30.2、32.8、29.8 mg·g-1。随着NaCl浓度的增加,西瓜幼苗叶片中的叶绿素含量逐渐减少。在NaCl浓度为400 mmol·L-1时,2x、3x、4x叶片中的叶绿素含量分别由33.0、33.6、33.4 mg·g-1减少到9.2、4.6、5.5 mg·g-1。叶绿素含量受低盐浓度影响较小,高盐浓度条件下,叶绿素含量随着NaCl胁迫时间的增加而逐渐减少,2x、3x、4x西瓜叶片叶绿素含量受NaCl胁迫后变化趋势一致,并且在各倍性之间叶绿素含量变化没有明显差异。

The chlorophyll contents were investigated by comparing their tolerances to O, 100,200,100 and 400 mmol· L^-1 NaC1 concentrations in diploid, triploid, and tetraploid watermelon seedlings. The contents of chlorophyll were measured by 95% ethanol. The results showed that the decreasing amplitude of chlorophyll contents changed less with the increasing of salt stress days under low salt concentration. The chlorophyll contents of leaves in 2x, 3x and 4x changed from 33.4,33.5, 32.3 mg·g^-1 to 30.2, 32.8,29.8 mg·g^-1 by prolonging stress time under 100 mmol· L^-1 NaC1 concentration, while at 400 mmol· L^-1 NaC1 concentration, they changed from 33.0,33.6,33.4 mg·g^-1 to 9.2,4.6,5.5 mg· g^-1. Chlorophyll contents in wa- termelon seedlings were less affected by low salt concentration, but the chlorophyll contents in 2x, 3x and 4x watermelon seedlings decreased with the increasing of salt stress days, the chlorophyll contents in the three plants showed the same trend with no obvious difference.