10种禾草苗期抗旱性的比较研究

采用盆栽断水方式模拟土壤干旱胁迫,研究不同程度干旱胁迫对10种禾草苗期7种抗旱性特征的影响,结果表明,随着干旱胁迫程度增加,禾草叶片含水量及相对含水量降低,叶片相对电导率与可溶性糖含量升高,重度干旱胁迫时,草地雀麦、无芒雀麦、苇状羊茅、沙生冰草和草芦根冠比增加,其余草种均有所降低,重度干旱胁迫对禾草株高胁迫指数与干物质胁迫指数影响不大;通过聚类分析可以将10种禾草按苗期抗旱性大小分为3类,强抗旱性禾草有无芒雀麦、草地雀麦、苇状羊茅,中抗旱性禾草有沙生冰草、蓝茎冰草、长穗偃麦草、鸭茅,弱抗旱性禾草有紫羊茅、猫尾草、草芦;通过主成分分析进一步确定10种禾草苗期抗旱性由强到弱的顺序为无芒雀麦>苇状羊茅>草地雀麦>鸭茅>沙生冰草>长穗偃麦草>蓝茎冰草>草芦>猫尾草>紫羊茅.

Drought resistance of ten seedling grasses

The effects of drought stresses on seven drought-resistant characteristics of ten seedling grasses were studied by reducing soil water in a pot experiment.The leaf water content(LWC) and leaf relative water content(LRWC) of the ten seedling grasses decreased,and their leaf soluble sugar content(LSSC) and leaf relative electrical conductivity(LREC) increased with improved drought stress resistance.During severe drought stress,the root/shoot of Bromus riparius,B.inermis,Festuca arundinacea,Agropyron desertorum and Phalaris arundinacea increased,but it decreased in the other five species.Drought stress did not significantly affect height stress index or dry matter stress index of the grasses.Cluster analysis gave three categories of grasses: High drought resistance grasses(B.inermis,B.riparius,and F.arundinacea);Medium drought resistance grasses(A.desertorum,A.smithii,Elytrigia elongate,and Dactylis glomerata);Low drought resistance grasses(F.rubra,Phleum pratense,and P.arundinacea).The order of drought resistance determined by principal component analysis was B.inermis>F.arundinacea>B.riparius>D.glomerata>A.desertorum>E.elongate>A.smithii>P.arundinacea>P.pratense>F.rubra.