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通过盆栽和室内试验研究了肉桂酸处理对蚕豆种子萌发,幼苗生长及尖孢镰孢菌菌丝生长,蚕豆枯萎病发生,根际微生物的活性、多样性和群落结构的影响。结果表明:肉桂酸处理抑制了蚕豆种子萌发及幼苗生长,并随处理浓度增加,抑制效应加强,对叶片数和根系的抑制效应最为显著。肉桂酸低浓度处理时显著促进尖孢镰刀菌菌丝生长,而高浓度处理则抑制菌丝生长。肉桂酸在100和200 mg·L-1处理时显著提高了蚕豆枯萎病的病情指数,显著增加了根际土壤中镰刀菌的数量,降低了微生物的活性(AWCD值)、多样性和丰富度指数。主成分分析表明,肉桂酸处理明显改变了蚕豆根际微生物群落结构,糖类、羧酸类和氨基酸类是区分肉桂酸处理导致土壤微生物群落变化的敏感碳源。肉桂酸处理降低了根际微生物多样性,促进病原菌的增殖,加剧了蚕豆枯萎病的发生,证实肉桂酸是蚕豆连作障碍中的自毒物质。
The effects of cinnamic acid treatment on the seed germination, seedling growth, Fusarium oxysporum mycelium growth, the occurrence of Fusarium oxysporum f. Sp., Activity of rhizosphere microorganisms and community structure were studied by potted and laboratory experiments. The results showed that cinnamic acid inhibited seed germination and seedling growth of Vicia faba. The inhibitory effect was enhanced with the increase of treatment concentration, and the inhibitory effect on leaf number and root system was the most significant. Cinnamic acid reduced the mycelial growth of F. oxysporum significantly when treated with low concentrations of cinnamic acid, while the treatment with high concentration inhibited mycelial growth. Cinnamic acid significantly increased the disease index of Fusarium oxysporum f. Sp. At 100 and 200 mg · L-1, significantly increased the amount of Fusarium in the rhizosphere soil, decreased the activity of microorganisms (AWCD), diversity and richness index. The principal component analysis showed that the cinnamic acid treatment significantly changed the microbial community structure in the rhizosphere of Vicia faba, and the sugars, carboxylic acids and amino acids were the sensitive carbon sources to distinguish the changes of soil microbial community caused by cinnamic acid. Cinnamic acid reduced rhizosphere microbial diversity and promoted the proliferation of pathogenic bacteria, aggravating the occurrence of fusarium wilt. It was confirmed that cinnamic acid was a toxic substance in the continuous cropping obstacle of broad bean.