6种化感物质对鬼针草种子萌发及根尖细胞有丝分裂的影响

Effects of Six Allelochemicals on the Seed Germination and Root Tip Cell Mitotic of Bidens pilosa L.

研究不同浓度阿魏酸、香草酸、槲皮黄素、木樨草素、茶碱和可可碱对鬼针草(Bidens pilosa L.)种子萌发、幼苗生长及根尖细胞有丝分裂的影响,以期筛选出安全有效的植物源除草剂。结果表明:除阿魏酸之外,其余5种化感物质对鬼针草种子萌发的抑制作用随浓度增大而增强。在1 mmol·L^(-1)处理下,6种化感物质对鬼针草种子萌发的抑制作用最强,化感综合效应指数分别为-0.929,-0.912,-0.889,-0.995,-0.959和-0.995;除木樨草素和可可碱外,其余4种化感物质在低浓度时促进幼苗生长,高浓度时抑制幼苗生长。在1 mmol·L^(-1)处理下,6种化感物质对鬼针草幼苗生长的抑制作用最强;除木樨草素和可可碱外,其余4种化感物质在低浓度下有丝分裂指数增大,随着浓度增大有丝分裂指数降低,同时分裂中期细胞增多,后-末期细胞减少。这表明,较高浓度的香草酸、槲皮黄素和茶碱对鬼针草种子萌发、幼苗生长和根尖细胞有丝分裂有较强的抑制作用,是筛选植物源除草剂的重要资源。

Effects of ferulic acid, vanillic acid, quercetin, luteolin, theophylline, and theobromine on the seed germination, seedling growth and root tip cell mitosis of Bidens pilosa were investigated. Results in dicated that the seed germination of B. pilosa was inhibited by vanillic acid, quercetin, luteolin, theophyl line, and theohromine. All, tested allelochemicals at the concentration of 1 mmol · L-1 had the strongest inhibitory effects on the seed germination of B. spilosa and the indices of synthesis effects were --0. 929, --0.912, --0.889, --0. 995, --0.99 and --0. 995. The root length and shoot height of B. pilosa were promoted under the low concentrations of tested allelochemicals, while the root length and shoot height were inhibited under the high concentrations of tested allelochemicals except for luteolin and theobromine. The inhibitory effects of tested allelochemicals on the seedling growth of B. pilosa were the strongest at the concentration of 1 mmol · L-1. Ferulic acid, vanillic acid, quercetin, and theophylline at low concen trations increased mitotic index and promoted root length. The mitotic index of B. pilosa decreased withthe increase of allelochemical concentration, whereas anaphase-telophase cell ratios decreased. It was con- cluded that vanillic acid, quercetin and theophylline at high concentrations had stronger allelopathic effects on the seed germination, early seedling growth and root tip cell mitotic of Bidens pilosa. Therefore, the tested allelochemicals are important resources for the development of botanical herbicide.