15份垂穗披碱草种质资源苗期抗旱性比较

The comparison in drought resistance of 15 germplasms resource of Elymus nutans at seedling stage

为了筛选出适宜川西北高寒牧区干旱环境下生长的垂穗披碱草(Elymus nutans)种质资源,采用室内盆栽法,对15份21 d龄的种质资源进行8 d的自然干旱处理,测定胁迫后各种质的叶绿素荧光参数、光合色素积累及相对电导率的干旱胁迫指数(DRI),并采用隶属函数法比较了15份不同垂穗披碱草种质资源抗旱性的差异。结果表明:干旱胁迫后,15份种质资源的最大光化学效率(Fv/Fm)、潜在光化学效率(Fv/F0)、表观电子传递速率(ETR)、光化学淬灭系数(qP)、叶绿素a(Chla)、叶绿素b(Chlb)及类胡萝卜素(Car)的含量均下降;而相对电导率(REC)与非光化学淬灭系数(qN)则有不同程度升高。15份垂穗披碱草种质资源苗期的抗旱性强弱依次为:E15>E10>E5>E14>E1>E2>E13>E9>E8>E11>E4>E7>E6>E3>E12。筛选出的抗旱性突出的材料为康北垂穗披碱草、I-1-1-14、11-22,其中康北垂穗披碱草作为国审品种,表现出的很强的优势,适合在干旱、半干旱地区普及推广,I-1-1-14、11-22可作为抗旱牧草新品种选育的备选材料。

To select the drought-resisant germplasm resources of Elymus nutans which is sutitabale for planting in arid environment of alpine pastoral area in Northwestern Sichuan,15 germplasm resources aged 21 days were treated with natural drought for 8 days.After drought stress,chlorophyll fluorescence parameters,photosynthetic pigment accumulation,and drought response index(DRI)of relative electrical conductivity(REC)in different germplasm under drought stress were measured.Furthermore,the difference of dorught-resistance of 15 germplasms were analyzed and compared by the method of membership function.Results showed that the maxinmal photochemical efficiency(Fv/Fm),potential photochemical efficiency(Fv/F0),apparent electron transfer efficiency(ETR),photochemical quenching(qP)of photoreaction center II(PSⅡ)of the 15 germplasms were all declined under the drought stress,and the contents of chlorophyll a(Chla),chlorophyll b(Chl b)and carotenoid(Car)also decreased..Nevertheless,REC and non-photochemical quenching(qN)parameters increased to some extent The drought-resistance of 15 germplasms resources at seedling stage was as follows:E15>E10>E5>E14>E1>E2>E13>E9>E8>E11>E4>E7>E6>E3>E12.The selected materials with outstanding drought resistance were‘Kangbei’,‘I-1-1-14’,‘11-22’.Kangbei,as a state-approved variety,has a strong advantage and is suitable for popularization in arid and semi-arid areas.I-1-1-14 and 11-22 can be used as alternative materials for breeding new varieties of drought resistant forage.