青藏高原地区野生老芒麦苗期抗旱种质材料的筛选

Screening of drought-resistant germplasm at seedlingstage of Elymus sibiricusat originated fromQinghai-Tibet Plateau

摘要:

为筛选苗期抗旱性较强的野生老芒麦种质材料,用于青藏高原人工牧草栽培与育种,采用砂培和盆栽2种培养方式,对青藏高原不同地区收集的25份老芒麦材料进行模拟干旱试验,并使用隶属函数法评价各材料的抗旱性,引入干旱变异指数筛选老芒麦抗旱性评价指标。结果表明:两次筛选结果相似,其中10-124、14-250、16-335、09-118、G23和09-035为抗旱材料,14-234、09-110、川草1号、09-089、09-249、09-129、09-150、09-053、G9、13-306、13-360和10-005为中等抗旱材料;1-1-4-2、09-210、09-149、1-1-5-13、青牧1号、13-364和14-004为不抗旱材料;(2)叶面积、根冠比、根长、丙二醛含量、脯氨酸含量、叶绿素含量、净光合速率、最大光化学效率、光化学淬灭系数和表观电子传递效率的干旱变异系数相对较大,可作为青藏高原老芒麦抗旱种质材料筛选的依据。综上,10-124、14-250、16-335、09-118、G23和09-035抗旱性较强,可作为青藏高原牧草栽培与育种的首选材料;叶面积、根冠比和根长等指标对干旱胁迫较为敏感,可作为老芒麦苗期抗旱性评价指标。

Abstract:

The Elymus sibiricus with strong drought resistance was selected for forage cultivation and breeding in Qinghai-Tibet Plateau.In this study,25 Elymus sibiricus germplasm collected from different areas of Qinghai-Tibet Plateau were exposed to simulated drought stress in sand culture.The membership function method was used to evaluate the drought resistance of each germplasm,and the drought variation index was introduced to screen the drought resistance evaluation index of Elymus sibiricus.The results of two screening experiments were similar,of which 10-124,14-250,16-335,09-118,G23 and 09-035 were classified as drought-resistant materials,14-234,09-110,Chuancao1,09-089,09-249,09-129,09-150,09-053,G9,13-306,13-360 and 10-005 were classified as medium drought-resistant materials,while 1-1-4-2,09-210,09-149,1-1-5-13,Qingmu1,13-364 and 14-004 were classified as drought-sensitive materials.Leaf area,root:shoot ratio,root length,malondialdehyde,proline,chlorophyll,net photosynthetic rate,maximum photochemical efficiency,photochemical quenching coefficient and apparent electron transfer efficiency had relatively large variation,and they could used as the basis for the selection of drought-resistant germplasm of Elymus sibiricus in the Qinghai-Tibet Plateau.Our study found that six germplasm,including 10-124,14-250,16-335,09-118,G23 and 09-035,had strong drought resistance,which could be used as the preferred materials for forage cultivation and breeding in Qinghai-Tibet Plateau.Furthermore,leaf area,root:shoot ratio and root length were sensitive to drought stress,which could be used as evaluation indexes for drought resistance of Elymus sibiricus.