模拟干旱胁迫下3种牧草种子萌发期抗旱性评价

以黑麦草、高羊茅和垂穗披碱草为研究对象,采用0%、5%、10%、15%和20%的PEG-6000浓度处理,测定发芽率、发芽势、发芽指数、活力指数、苗高、根长、苗鲜重和根鲜重,并通过隶属度函数法计算3种牧草种子萌发期抗旱性,运用加权和法得到3种牧草种子综合抗旱指数。结果表明:除根长外,3种牧草其余指标均随PEG-6000浓度的升高而逐渐降低;在发芽指数和活力指数方面,高羊茅抗旱性强于黑麦草和垂穗披碱草;其余各指标中,垂穗披碱草抗旱性最强,黑麦草最弱。综合抗旱指数表明,3种牧草种子萌发期抗旱性由强到弱排序为:垂穗披碱草>高羊茅>黑麦草。

Drought-resistant Evaluation of Three Kinds of Herbage During Seed Germination in Artificial Drought Conditions

The germination rate,germination potential,germination index,vigor index,seedling height,root length,seedling fresh weight and root fresh weight of Lolium perenne,Festuca arundinacea and Elymus nutans were determined under PEG-6000 treatment with 0%,5%,10%,15%and 20%concerntrations.Further,the drought resistance of three kinds of herbage at germination was evaluated by membership function method and the drought resistance index of three kinds of herbage seeds was also obtained by weighted sum method.The results showed that the indexes except for root length decreased gradually with the increase of PEG-6000 concentration in 3 herbage species.In terms of germination index and vigor index,the drought resistance of F.arundinacea was stronger than that of L.perenne and E.nutans.Additionally,among the other indexes,the strongest and the weakest drought-resistance were E.nutans and L.perenne respectively.Based on the analysis of comprehensive drought index,the drought resistance of three kinds of herbage in germination stage ranged from strong to weak were E.nutans>F.arundinacea>L.perenne.