干旱胁迫对柳枝稷幼苗生理特征的影响

柳枝稷（Panicum virgatum L 。）是一种优良的纤维素类草本能源植物，被认为是一种理想的可再生替代能源，同时又具有优良的牧草特性及水土保持功能。研究水分胁迫对柳枝稷幼苗生理特性的影响，可为其在干旱地区大面积栽培种植提供依据。研究结果表明，柳枝稷幼苗叶片水分随着停水时间延长逐渐降低，但是叶片含水量下降趋势较为平缓，在试验时段内，柳枝稷叶片具有一定保水能力。干旱胁迫下，柳枝稷幼苗叶片的叶绿素a含量、叶绿素总含量与对照相比均表现为明显减少，干旱对叶绿素a的影响要明显高于叶绿素b；干旱胁迫后期，柳枝稷植株体内游离脯氨酸和可溶性糖含量显著升高，丙二醛含量也有明显增加，可见，柳枝稷幼苗能通过增加游离脯氨酸及提高可溶性糖含量来缓解土壤干旱胁迫的伤害，表现出一定的抗干旱特性。

The Influence on Physiological Characteristics of Switchgrass Seedlings under Soil Drought Stress

Biomass energy was considered to be an ideal renewable alternative energy and herbaceous energy plants as an important biomass resources became research hot spot all over the world. Switch-grass （Panicum virgatum L.） was international recognized as the most suitable bioenergy plant for the past few years. Provided the basis to a large area of cultivation in arid regions, we studied physiologi-cal characteristics of swithgrass seedlings under soil drought condition. The result showed that the leaf water content of swithgrass seedlings decreased with drought stress increasing, but the change kept sta-ble with some water retaining capacity of swithgrass seedlings. Chlorophyll a and total chlorophyll con-tent significantly declined under water stress. The drought affected to chlorophyll a significantly higher than to chlorophyll b. The content of proline and soluble sugar had a large increase in the late drought stress,and like that,the same trend was observed in MDA,which showed soil drought stress had sig-nificantly affected by the increase of the proline and soluble sugar in swithgrass seedlings and the char-acteristics of resistance to soil drought.