外源水杨酸对多年生黑麦草耐盐性的影响

因水杨酸对盐胁迫下植物的生长和抗性生理具有重要调节作用,在水培条件下,通过裂区设计(主处理为水杨酸,浓度为0、0.25、0.50、1.00 mmol/L;副处理为NaCl胁迫,浓度为0、250 mmol/L)研究了水杨酸对多年生黑麦草耐盐性的影响。结果表明:浓度为0.25、0.50 mmol/L的水杨酸能提高盐胁迫条件下多年生黑麦草的耐盐性,其中0.25 mmol/L比0.50 mmol/L水杨酸提高耐盐性作用更明显;显著提高了坪观质量、根系总长度、根系活力以及叶片光合速率、气孔导度、相对含水量、叶绿素含量、脯氨酸含量,降低了叶片电解质渗出率和丙二醛含量。1.00 mmol/L的水杨酸对多年生黑麦草的耐盐性有抑制作用,降低了坪观质量、光合速率、气孔导度、叶绿素含量、脯氨酸含量,增加了电解质渗出率和丙二醛含量,对相对含水量、根系长度、根系活力的影响不显著。 

Effect of exogenous salicylic acid on salt tolerance in perennial ryegrass

Salicylic acid ( SA ) has an important regulatory effect on plant growth and resistance physiology under salt-stress conditions. The purpose of this study was to explore the effect of salicylic acid on salt tolerance in perennial ryegrass ( Lolium perenne ) . Under hydroponic conditions, split-plot design was adopted ( salicylic acid was used for the main treatment with four levels of 0 , 0. 25 , 0. 50 and 1. 00 mmol/L;NaCl stress was used for the sub-treatment with two levels of 0 and 250 mmol/L) . The results showed that both 0. 25 and 0. 50 mmol/L levels of salicylic acid could improve the salt tolerance of perennial ryegrass under salt-stress conditions, in that they significantly increase the turf visual quality, total root length, root activity (P<0. 05), photosynthetic rate, stomatal conductance, leaf relative water content, total chlorophyll content and the proline content ( P <0. 05 ) , and decrease the electrolyte leakage and malondialdehyde content of leaves. However, the salicylic acid treatment at 1 mmol/L had an inhibiting effect on salt tolerance of perennial ryegrass: it decreased the turf visual quality, photosynthetic rate, stomatal conductance, total chlorophyll content and the proline content, and increased the electrolyte leakage and malondialdehyde ( MDA ) content of leaves. But it had no significant effects on relative water content, root length and root activity ( P>0. 05 ) . By evaluating the influence of salicylic acid at three concentrations on salt tolerance of perennial ryegrass, we reached the conclusion that 0. 25 and 0. 50 mmol/L salicylic acid promoted the salt tolerance of perennial ryegrass with the former having better effects, but 1. 00 mmol/L salicylic acid, on the contrary, inhibited its salt tolerance.