不同种源地云杉的苗期抗旱性评价

以青海云杉、黑云杉、欧洲云杉、蓝云杉和白云杉不同种源的2年生苗木为试材,测定其在不同水分梯度下叶片的保护酶(SOD、POD和CAT)活性、质膜透性(RPP)、游离脯氨酸(Pro)含量、可溶性糖(SS)含量、丙二醛(MDA)含量、叶绿素含量等生理指标,分析其生理指标的变化规律,并利用隶属函数法和灰色关联度法研究其抗旱性.结果表明:在连续干旱胁迫下,5种云杉的SOD、CAT活性和Pro含量均呈现先升高后降低的趋势,SS含量、MDA含量均呈逐渐增加的趋势,POD活性呈降-升-降的趋势,叶绿素则呈逐渐降低的趋势,各指标的变化幅度在不同种及种源间的表现不一.5种云杉的苗期抗旱性大小依次为青海云杉>黑云杉>欧洲云杉>蓝云杉>白云杉;不同种源地云杉的抗旱性大小依次为青海云杉001>黑云杉001>欧洲云杉001>黑云杉002>欧洲云杉002>蓝云杉001>蓝云杉002>白云杉001.关联度分析结果表明,各项抗旱指标与平均隶属函数值的关联顺序依次为过氧化氢酶>可溶性糖>脯氨酸>质膜透性>过氧化物酶>超氧化物歧化酶>丙二醛>叶绿素.

Evaluation of seedling drought resistance of five species in the genus Picea Linn.from diferrent provenance

The seedling drought resistance of five species in the genus Picea Linn.from different provenance,such as Picea crassifolia,Picea mariana,Picea abies,Picea pungens and Picea glauca,was comprehensively identified and evaluated using the simulated drought stress method.Eight physiological indexes such as content of proline(Pro),soluble sugar(SS),malon-dialdehyde(MDA) and chlorophyll(a+b) in the leaves,the activities of superoxide dismutase(SOD),catalase(CAT),peroxidase(POD),relative permeability of plasma(RPP) were measured under four natural moisture content gradients.The results showed that the activities of SOD,POD and CAT of five tree species gradually increased first and then decreased.Content of SS,MDA and relative permeability of RPP gradually decreased,while the activity of POD showed a gradual decreasing-increasing-decreasing trend.The changing of physiological indexes in different species showed different range.The drought resistance of five species decreased in order as follows:Picea crassifolia>Picea mariana>Picea abies>Picea pungens>Picea glauca.The drought resistance of eight provenances decreased in order as follows:Picea crassifolia 001>Picea mariana 001>Picea abies001>Picea mariana002>Picea abies 002>Picea pungens001>Picea pungens002 >Picea glauca001.The results of grey correlative degree analysis indicated that the correlation order between appraise indexes of drought resistance and average subordinate function values was as:CAT>SS>Pro>RPP>POD>SOD>MDA>chl(a+b).