毕氏海蓬子种子萌发及幼苗生长对盐分和水分胁迫的响应

Effects of Salt and Water Stresses on the Seed Germination and Seedling Growth of Salicornia bigelovii Torr.

以等渗的不同浓度NaCl和等渗PEG6000处理盐生植物毕氏海蓬子种子,测定其发芽率、幼苗茎长、地上部O2-·产率、超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性和脯氨酸(Pro)和可溶性蛋白质(SP)的含量。结果表明,NaCl和等渗PEG6000对海蓬子种子萌发都有抑制作用,且PEG的抑制程度大于等渗的NaCl。PEG6000处理的幼苗地上部生长显著低于对照;低盐NaCl处理后幼苗地上部生长稍高于对照,但差异不显著,随着盐度的增加,地上部长度下降。O2-·产率随着PEG浓度的升高而增加。PEG6000胁迫下O2-·产率均高于NaCl处理。两种处理下植物体内抗氧化酶系统变化较复杂,PEG6000处理后SOD、POD的活性均比NaCl处理的要低,CAT活性相反。9.5%、13.0%PEG6000处理下,毕氏海蓬子Pro积累比较显著。毕氏海蓬子对盐分较强的适应性主要在于维持较高的SOD、POD活性和较低的体内活性氧水平。

Seed germination, seedling growth, O2^-· producing rate, SOD, POD and CAT activities, proline and soluble pro-tein contents were tested in Salicornia bigelovii treated with different NaCl and polyethylene glycol 6000（PEG 6000）.The results showed that NaCl and PEG stresses lowered and delayed germination.The inhibition of PEG 6000 on germination was more than that under iso-osmotic NaCl stress.Also did so in seedling growth.O2^-· producing rate increasing along with PEG6000 concentration was more than that under NaCl treatment.Anti-oxidation system was complicated under two kinds of stresses.SOD, POD activities under PEG 6000 stresses were markedly less than that under NaCl stresses.It was contrary on CAT change.Proline accumulation in Salicornia bigelovii was high under 9.5%～13.0% PEG 6000 stresses.The adaptability of Salicornia bigelovii to salt stress was mainly caused by high SOD, POD activities and lower O2^-· level.