松嫩草地不同成熟度羊草种子对盐胁迫的发芽响应

羊草(Leymus chinensis)是多年生根茎型优质禾本科饲草,也是东北松嫩盐碱化草地的建群植物,针对不同成熟度羊草种子对盐胁迫发芽响应在国内外未被涉及的现状,本研究以NaCl为盐胁迫处理液,设置4个胁迫浓度(50, 100, 200和400 mM)研究不同成熟度(盛花期后24, 29, 34和39 d)羊草种子对盐胁迫的发芽响应。结果表明:不同成熟度的羊草种子同样表现出不同的耐盐性,盛花期后39 d的羊草种子活力最大,发芽率、发芽势、复萌率以及总发芽率均优于其余3个发育时期的种子。另外,盐胁迫下未萌发的羊草种子复萌率随着胁迫强度的增加而增加,这是羊草种子对高盐胁迫的生理适应策略,以休眠形式躲避不良环境,待土壤盐浓度降低时萌发出土。本研究可为羊草种子的发育与抗逆生理学等研究提供一定的科学依据。

Germination Responses of Different Maturity Leymus chinensis Seeds to Salt Stress in Songnen Grassland

Leymus chinensis(Trin.) Tzvel. is a perennial rhizomatous forage grass species of Poaceae, which is also the dominant grass species in Songnen Salt-alkali Grassland of Northern China. Due to the fact that no information existed concerning the germination responses of different maturity Leymus chinensis seeds, four kinds of salt stress concentration(50, 100, 200, 400 mM) were designed here in order to investigated the ecological responses of different maturity Leymus chinensis seeds(24, 29, 34 and 39 days after blooming) on the salt stress. Results showed that the germination responses of Leymus chinensis seeds to salt stress greatly differed from different maturation times. Seeds at 39 days after blooming had the highest vigor and the best quality. The germination percentage, germination energy, recovery percentage and total germination percentage were superior to others. In addition, the germination recovery percentage of the seed before germination treated by salinity stress increases compared with no treated. This may be an adaptive strategy of seed germination to salt stress, being a state of dormancy to escape from the rigorous environment. The research can provide scientific basis for seed development and stress tolerance science.