须芒草、虉草和柳枝稷对干旱和盐胁迫的生理响应

Physiological responses of bluestem,reed canarygrass and switchgrass under drought and salinity stress

以营养生长期须芒草(Andropogon virginicus)、虉草(Phalaris arundinacea)和柳枝稷(Panicum virgatum)为试验材料,采用三因素三水平正交设计,用盆栽土培法研究了在不同土壤含水量和盐分浓度下3种草的脯氨酸含量、可溶性糖含量、过氧化物酶(POD)活性和过氧化氢酶(CAT)活性的变化。结果表明,随干旱胁迫加重,3种草脯氨酸、可溶性糖、POD活性、CAT活性均呈持续增加或先减少后增加趋势,而柳枝稷CAT活性则先增加后减少,且在7%土壤含水量下达到最大值;随盐胁迫加重,3种草脯氨酸、可溶性糖、POD活性呈持续增加或先减少后增加趋势,而须芒草可溶性糖含量和POD活性则先增加后减少,且在2‰盐分浓度下达到最大值,须芒草、虉草、柳枝稷CAT活性均先增加后减少,且分别在2‰、4‰、6‰盐分浓度下达到最大值。可初步得出须芒草、虉草对干旱具有一定适应能力,但对NaCl较敏感,柳枝稷对干旱和NaCl均具有较强的适应能力。

Physiological responses of bluestem （Andropogon virginicus ）, reed canarygrass （Phalaris arundinacea）, switchgrass （Panicum virgaturn） under drought and salinity were studied at their vegetative growth stage. The experiments were conducted in pots in greenhouse using orthogonal matrix design at three factors （plant, soil water content and saline concentration） with three levels. The results showed that the contents of proline and soluble sugar, the activities of peroxidase （POD） and catalase （CAT） in leaves only increased or decreased first and then increased along with the reduction of the soil water con- tent. However, the CAT activity of switchgrass firstly increased and then decreased and reached maximum at 7% water concentration. The contents of proline and soluble sugar, POD activity in leaves only increased or firstly decreased and then increased along with the increment of saline concentration, whereas in bluestem increased first and then decreased, reached maximum at 2‰ salt concentration. The CATactivities in bluestem, reed canarygrass and switchgrass firstly increased and then decreased, and reached maximum at saline concentrations of 2‰, 4‰ and 6‰, respectively. Bluestem and reed canarygrass had the strong adaptive capacity under drought stress, but were sensitive to salt stress. Switchgrass has strong adaptability under drought and salinity stress.