决明属（Chamaecrista spp）豆科牧草8个品种化感潜力的研究

研究决明属（Chamaecrista spp.）豆科牧草8个品种圆叶决明（Chamaecrista rotundifolia）CPI86134、CPI34721、CPI86178、CPI3248、ATF2232、CPI57503和羽叶决明（Chamaecrasta nictitans）ATF2217、ATF2219]对禾本科牧草百喜草（Paspalum notatum）的化感作用,以确定该8个豆科牧草品种的化感潜力。结果表明,8个决明属豆科牧草品种具有较强的化感作用;随着浓度的逐渐降低,8个品种开花期浸提液的化感抑制作用逐渐减弱,结荚期浸提液的化感促进作用逐渐加强;同一品种,同一生长时期,不同浓度（5%、7.5%和10%）的化感作用综合效应表现不同;同一生长时期,同一浓度,不同品种的化感综合效应表现也不同。可见,决明属牧草8个品种的化感作用受浓度、生长时期和品种的影响。

Evaluation of Allelopathic Potential in Eight Accessions of Chamaecrista spp

Eight accessions of Chamaecrista spp,including 6 accessions of Chamaecrista rotundifolia (CPI86134,CPI34721,CPI86178,CPI3248,ATF2232 and CPI57503) and 2 accessions of Chamaecrasta nictitans(ATF2217 and ATF2219) were collected at the flowering or fruitsetting stage and extracted,and the extracts were prepared at the concentrations of 5%,7.5% and 10% and placed on the incubator to observe their allelopathic activities against germination and growth of Paspalum notatum. Results showed that with the fall in concentration,the extracts of all the 8 accessions gave a decreasing allelopathic inhibition against P. notatum when prepared at the flowering stage but an increasing allelopathic inhibition against P. notatum when prepared at the fruitsetting stage. Extracts of the same accessions at the same growth period at different concentrations(5%,7.5% and 10%) produced different overall allelopathic activities; extracts of different accessions prepared at the same growth stage and the same concentration also gave various allelopathic results. In short,the allelopathy of all the accessions of Chamaecrista spp.against P. notatum depends on the accessions and their extract concentration and growth stages.