关键词: 种子活力, 主成分分析, 抗逆指数, 小麦

Abstract: We evaluated the response of rhizosphere AM fungi, root infection rate and seasonal dynamics to grazing. Three dominant plant species (Seriphidium transiliense, Stipa capillata, Festuca ovina, Carex liparocarpos) in theSeriphidiumdominated desert grassland were selected as the research materials. The results showed that the spore density and species richness of AM fungi and root colonization rate of plants decreased significantly with increasing grazing intensity (P<0.05), and diversity index decreased significantly under overgrazing (P<0.05). The spore density, species richness and root colonization rate in the 0-10 cm soil layer were significantly higher than those in the 10-20 cm and 20-30 cm soil layers (P<0.05) under the same grazing intensity. The diversity index showed no significant change with increasing soil depth (P>0.05). Meanwhile, different host plants had different dependence on AM fungi, and the colonization rate was in order of S. transiliense>F. ovina>C. liparocarpos. The spore density, species richness, root colonization rate of arbuscular mycorrhizal fungi had a seasonal variation. All three characters showed a “double peak” phenomenon, reaching the peak in June and September, which were almost synchronized with the growth rhythm of vegetation. Temperature had no significant effect on the spore density, richness and colonization rate of AM fungi, while rainfall had a significantly positive effect on the colonization rate (P<0.01).

Key words: wheat (Triticum aestivum), seed vigor, adversity resistance index, principal component analysis.