中文摘要：

利用气相色谱仪测定了7种温带常见牧草表皮蜡质层饱和烷烃（N—alkane）的浓度．对同一牧草种不同生育期的饱和烷烃模式进行方差分析。结果表明，不同生育期牧草饱和烷烃浓度模式存在显著的差异。在生长季节，绝大多数牧草的C29或C31的浓度超过50μg／g，可以应用双烷烃法来估测放牧家畜的采食量。主成分分析和方差分析的结果表明．除了老芒麦与披碱草或羊草在9月份出现重叠外，其它牧草的饱和烷烃特征模式在各取样时间均出现显著差异。因此，在温带草原上．应用饱和烷烃技术估测放牧家畜的采食成分是可行的。

英文摘要：

N-alkane concentrations in the cuticular wax of seven temperate grass species were assayed by gas chromatography. One-way ANOVA was used to examine the effect of sampling time on the concentrations of individual N-alkanes in the same species. The results showed that the effect of growth stage on the N-alkane concentrations of the forage species tested was significant. The concentrations of C29 or C31 in the forage species studied all exceeded 50μg/g DM, indicating they could be used to estimate the intake of grazing animals. The results of principal component and one-way ANOVA indicated that it should be possible to use alkane tech- niques to estimate dietary composition of grazing animals in the grasslands of the north temperate zone of China. At all sampling times there were significant differences （P〈0.05）in terms of the alkane patterns, between the grass species except for those between Elymus sibiricum and Elymus dahuricus or Leymus chinensis when sampled in September 2004.