四种果园绿肥种子在PEG-6000模拟干旱胁迫下的萌发特性与抗旱性评价

Germination Characteristics and Evaluation on Drought Resistance of Four Kinds of Orchard Green Manure Crops under PEG-6000 Stress

本试验采用不同浓度聚乙二醇(PEG-6000)溶液模拟干旱胁迫的方法,对黑麦草、鼠茅草、二月兰、毛叶苕子4种果园绿肥种子的萌发特性和抗旱性进行综合评价。结果表明,在PEG-6000浓度为5%时,黑麦草、鼠茅草的相对发芽率分别增加3.26、6.41个百分点,说明低浓度的PEG-6000对黑麦草、鼠茅草种子萌发有一定促进作用;随着胁迫浓度的升高,4种绿肥种子的发芽率、胚根长、胚芽长、萌发胁迫指数、萌发抗旱指数不断下降。隶属函数分析表明不同绿肥种子各单一指标的耐旱性强弱顺序不尽相同,根据综合评估指标值得出4种绿肥种子抗旱性顺序为毛叶苕子>黑麦草>鼠茅草>二月兰。本研究结果对华北地区果园耐旱绿肥种类的选择具有一定指导意义。

The experiment was conducted to study the germination characteristics and evaluate the drought resistance of four orchard green manure crop species(Lolium perenne L.,Vulpia myuros C.,Orychophragmus violaceus L.,Vicia villosa Roth)by simulating drought stress using different concentrations of PEG-6000 solution.The results showed that when the PEG-6000 concentration was 5%,the relative germination rates of Lolium perenne L.and Vulpia myuros C.increased by 3.26 and 6.41 percentage points,respectively,which indicated that low concentration of PEG-6000 had a certain promoting effect on seed germination of Lolium perenne L.and Vulpia myuros C.The seed germination rate,radicle length,plumule length,germination stress index and germination drought resistance index of all species decreased with the increase of PEG-6000 concentration.Through membership function analysis,it was found that the order of drought tolerance of different green manure species in each single index was different.The order of drought resistance of the four species was Vicia villosa Roth>Lolium perenne L.>Vulpia myuros C.>Orychophragmus violaceus L.based on comprehensive evaluation.The results of this study had certain guiding significance to the selection of drought-tolerant green manure species for orchards in North China.