少花蒺藜草种子水浸提液对3种禾本科牧草种子萌发的化感效应

为了解少花蒺藜草（Cenchrus pauciflorus）的化感潜力,试验采用生物测定法研究了不同浓度（0、25%、50%、75%、100%）的少花蒺藜草种子水浸提液对无芒雀麦（Bromus inermis）、梯牧草（Phleum pratense）及冰草（Agropyron cristatum）种子的化感作用。结果表明,少花蒺藜草种子水浸提液对3种受体植物种子萌发和幼苗生长均有不同影响。少花蒺藜草种子水浸提液对无芒雀麦种子的发芽势、发芽指数无显著影响,但对其根芽比有显著影响;少花蒺藜草种子水浸提液对梯牧草种子的发芽率、发芽指数、发芽势影响不大,但对根芽比影响显著（P〈0.05）;少花蒺藜草种子水浸提液对冰草种子的发芽率、发芽指数、发芽势及根芽比均有显著影响（P〈0.05）,在100%水浸提液浓度下发芽率仅为18.6%,比对照组低56.8%,发芽势和发芽指数分别为6.7%、3.24,比对照组分别低39.3%、8.94。

Allelopathic Effect of Seed Aqueous Extracts from Cenchrus pauciflorus on Seed Germination of Three Gramineous Grasses

To understand the allelopathic potential of Cenchrus pauciflorus, the allelopathy of different concentrations （0,25%, 50% ,75%, 100% ） of seed aqueous extracts from Cenchrus pauciflorus on seed germination of Bromus inermis, Phleum pratense and Agropyron cristatum was assessed by bioassay. The results showed that the seed aqueous extracts from Cenchrus pauciflorus had effects on seed germination and seedling growth of the three gramineous grasses in different degrees. The seed aqueous extracts from Cenchrus pauciflorus had no significant effects on germination potential and germination index of Bromus inerrnis, but had significant effects on its ratio of root to sprout. The seed aqueous extracts from Cenchrus pauciflorus had no significant effects on germination rate, germination index and germination potential of Phleum pratense, but had significant effects on its ratio of root to sprout （P〈0.05）. The seed aqueous extracts from Cenchrus pauciflorus had significant effects on germination rate, germination index, germination potential and ratio of root to sprout of Agropyron cristatum （P〈0.05）; the germination rate of Agropyron cristatum seed in 100% seed aqueous extracts from Cenchrus paucifloru was 18.6%, which was decreased by 56.8% than that of control; the germination potential and germination index was 6.7% and 3.24, which was decreased by 39.3% and 8.94 than that of control, respectively.