摘要在温室条件下,采用反复干旱法,对引进的20份无芒雀麦(Bromus inermis Leyss.)种质材料,以存活率、株高、绿叶数、地上生物量、地下生物量和根冠比6个指标的抗旱系数值,采用聚类分析法、标准差系数赋予权重法进行综合评价.结果表明:20份无芒雀麦苗期抗旱性划分成3个级别,其中抗旱性较强的有9份材料,抗旱性较弱有6份材料,抗旱性居中的有5份材料.20份无芒雀麦种质材料苗期抗旱性排序结果为ZXY06P-1621抗旱性最强,ZXY05P-1171最弱.不同抗旱级别种质材料的光合特性表现为:随着持续干旱胁迫延续,其光合速率(Pn)、蒸腾速率(Tr)和气孔导度(Gn)均呈下降趋势,复水后迅速上升；而CO2浓度的变化趋势则呈相反变化趋势,且在整个胁迫过程中变化差异不显著.干旱胁迫下抗旱性强的材料能够保持较高的光合性能.%Average survival rate, plant height, numbers of green leaves, above-ground biomass, underground biomass, root/shoot ratio of 20 accessions of Bromus inermis Leyss. Were measured using cluster analysis and standard deviation coefficient allocation weighted method at the seedling stage in green house to evaluate comprehensively drought resistance. Result showed that 20 accessions of B. Inermis were classified into three drought resistant grades. ZXY05P-0854 was the strongest drought resistant germplasm at the seedling stage and ZXY05P-1135 was the weakest one among tested 20 accessions. Photosynthetic rates, transpiration rates and stomatal conductance were decreased with continuing drought stress then increased after rehydration. The change of intercellular CO2 consistence did not show significantly different during drought stress. All data suggest that accessions with stronger drought resistance have stronger photosynthetic capability under drought stress.
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