低温胁迫对10份鹅观草属野生种质抗寒生理指标的影响

为研究低温胁迫对鹅观草属(Roegneria)野生种质抗寒相关生理指标的影响,以采集自青海三江源区的鹅观草属6个野生种10个居群的植物为研究材料,测定其幼苗在-25~5℃低温胁迫下叶绿素(Chl)、可溶性糖(SS)、丙二醛(MDA)和游离脯氨酸(Pro)含量、过氧化氢酶(CAT)活性、过氧化物酶(POD)活性以及细胞膜透性的变化。结果表明,低温胁迫下供试材料细胞膜透性、Chl含量、MDA含量、SS含量、Pro含量以及CAT、POD活性等抗寒生理指标均有显著变化,不同材料间变化幅度不同,并呈现出不同的变化规律,电解质渗出率持续增加,增加幅度为"小-大-小"的"S"曲线;MDA含量先是所有材料一致逐步提高,后是部分材料降低;CAT活性、POD活性、SS含量和Pro含量变化呈现先增加再降低的倒"V"型;9种供试材料的Chl含量持续降低;应用隶属函数法综合评价鹅观草属各材料的抗寒性能,抗寒性由强到弱顺序为玉树鹅观草(Roegneria yushuensis)(玛多)玉树鹅观草(Roegneria yushuensis)(铁卜加)玉树鹅观草(Roegneria yushuensis)(兴海)肃草(R.stricta)(同仁)曲芒异芒草(R.abolinii var.divaricans)(湟源)曲芒异芒草(R.abolinii var.divaricans)(泽库)短柄鹅观草(R.brevipes)(曲麻莱)紫穗鹅观草(R.purpurascens)(麦秀林场)短柄鹅观草(R.brevipes)(泽库)毛穗鹅观草(R.trichospicula)(泽库)。

Effect of low temperature stress on the cold-resistance physiological indexes of 1 0 germplasm resources of Roegneria in Qinghai

In order to study the effect of low temperature on the physiological indexes of 10 populations of six wild species belonging to the Roegneria genus in the Three Rivers region of Qinghai,seedlings with four to five leaf stages were used as experimental materials,and the leaf chlorophyll (Chl),soluble sugar(SS),malondial-dehyde(MDA),free proline(Pro),catalase(CAT)and peroxidase(POD)activities,and cell membrane per-meability were measured under low temperature stress of between —25 and 5 ℃.The results showed that the cold resistance indexes of plant materials,such as Chl content,MDA,SS content,Pro content,and CAT and POD activity were significantly different under low temperature stress compared to the control.Different mate-rials have different change ranges,and present different change rules,that is electrolyte permeability continues increasing by increasing the size of the S curve.The MDA content of the all experimental materials tended to remain consistent first increase,and then decrease.The contents of SS and Pro presented as an inverted V-shape,increasing first and then decreasing.The Chl content of nine materials continued to decrease.Mem-bership function analysis showed the order of cold resistance of the 10 Roegneria germplasms is:Roegneria yushuensis (Maduo)> R.yushuensis (Tiebujia)> R.yushuensis (Xinhai)> R.stricta (Tongren)>R.abolinii var.divaricans(Huangyuan)>R.abolinii var.divaricans (Zeku)>R.brevipes (Qumalai)>R.purpurascens (Maixiu )>R.brevipes (Zeku)>R.trichospicula (Zeku),in order from the strongest to weakest.