介质供氮水平对10种禾草幼苗生长及氮效率的影响

以10种常用禾草幼苗为材料,通过霍格兰溶液培养法观测了不同供氮水平下禾草的生长及氮效率特性,比较不同禾草的耐介质低氮特征差异.结果表明:介质低氮环境对草地雀麦的株高、根长、根体积、叶面积、地上和地下生物量,以及无芒雀麦的株高、根体积和根长的影响较小;不同介质供氮水平下,草地雀麦能维持相对较高的叶绿素含量,无芒雀麦与苇状羊茅具有较强的氮素吸收和同化能力,从而使草地雀麦、无芒雀麦与苇状羊茅表现出相对较强的耐介质低氮特性.可见,不同禾草草种幼苗对介质供氮水平变化反应存在明显差异,据此可筛选耐介质低氮的禾草草种资源.

Comparative Study on Response to Medium with Different Nitrogen Supply Levels of Ten Grass Species during Seedling Stage

The experiment was conducted to observe biological characteristics of ten grass species under medium with different nitrogen supply levels and study the characteristics of medium poor nitrogen resistance of different grass species by using Hoagland's nutrient solution.The results showed that the characteristics of medium poor nitrogen resistance of different grass species reflected dissimilarly by decreasing medium with nitrogen supply levels.Medium poor nitrogen had less effect on plant height,root length,root volume,leaf area,aboveground and underground biomass of Bromus riparius,plant height and root length,root volume of Bromus inermis;Bromus riparius had stronger ability to maintain higher chlorophyll content,and Bromus inermis and Festuca arundinacea had stronger nitrogen absorbability and assimilation under medium with different nitrogen supply levels.Therefore,medium poor nitrogen resistance of Bromus riparius,Bromus inermis and Festuca arundinacea was better than others.The results could be used to select resource of grass species with medium poor nitrogen resistance.