摘要 : Most parts of alfalfa plants have been reported to contain autotoxic substances that inhibit seed germination and early seedling growth. Effects of seed leachates of alfalfa (Medicago sativa cv. Vernal) were evaluated for inhibiti... 展开 Most parts of alfalfa plants have been reported to contain autotoxic substances that inhibit seed germination and early seedling growth. Effects of seed leachates of alfalfa (Medicago sativa cv. Vernal) were evaluated for inhibition of alfalfa germination and root growth through a bioassay. Seeds (40 g) were soaked in 1 litre deionized water for 1-48 h. Increasing soaking time increased the degree of inhibition of seedling root length, while hypocotyl length was not affected. In another experiment,1-20 g seeds were soaked in 1 litre deionized water for 24 h. Increasing concentration of seed extract progressively decreased root length, whereas hypocotyl length was not affected. Extracts did not affect final germination or speed of germination. Extracts from ground seeds significantly reduced speed of germination (GT 50) and root length. The results indicate that release of autotoxic substances from seeds during seed imbibition was increased with increased soaking time and amount of seeds, and that autotoxicity was greater from ground seeds than whole seeds. 收起