Study On The Effect And Mechanism Of Trichokonins On Lily Root Rot

Lily is a kind of important garden flower plant,the flower appearance is gorgeous,the flower is big and fragrant.But in recent years,lily root rot has become an important factor restricting lily industry development.In this study,lily root rot was isolated and identified by"Sorbonne"as the research object,and the pathogenic bacteria of lily root rot was tested.The control effect and mechanism of Trichokonins,an antimicrobial peptide isolated from trichoderma elongata SMF2,on lily root rot were studied.The results are as follows:1.Isolation and identification of pathogenic bacteria.Two pathogenic bacteria were isolated and purified from the root rot of Oriental lily'Sorbonne'by using kirschner's rule,and two kinds of pathogenic bacteria were identified by comprehensive morphological characteristics and molecular biology methods,respectively Fusarium solani and Fusarium oxysplorum.2.Biological characteristics test of pathogenic bacteria.The determination to find the most suitable for 25³0?two pathogenic bacteria growth,spore production;When the pH value was 6⁸,it was most beneficial to the growth of pathogenic bacteria hyphae.When the pH value was 9,the spore yield of Fusarium oxysporum was the highest.Mycelium development was best when glucose and sucrose were used as carbon sources for pathogenic bacteria,but the use of fructose was more conducive to spore-producing of Fusarium solanum,and trehalose was more conducive to spore-producing of Fusarium oxysporum.When yeast extract and beef extract were used as nitrogen sources,mycelium growth of two pathogenic bacteria of lily root rot was the best.Glycine is the most suitable nitrogen source for sporulation of Fusarium solanum.The yeast extract medium was most suitable for spore-producing Fusarium oxysporum.3.In order to screen the biocides with strong inhibitory activity against lily root rot fungus,the indoor bacteriostatic effect of 5 biocides and 1 chemical biocides was tested.The results showed that matrine had the strongest inhibitory effect on mycelial growth of Fusarium oxysporum and Fusarium solanum,with EC₅₀0 of 5.435 mg/L and2.226 mg/L,respectively.The inhibitory effects of mycetin?3.0%?and matrine?0.3%?on the conidia germination of Fusarium oxysporum were strong,with EC₅₀0 of 1.257 mg/L and8.432 mg/L,respectively.The activity of 0.5%emodin methyl ether and 0.3%matrine in inhibiting the conidia germination of Fusarium solanum was higher,and the EC₅₀0 were1.439 mg/L and 3.388 mg/L,respectively.4.Study on the bacteriostasis and control effect of Trichokonins.The study found that different concentrations of Trichokonins were used to treat both pathogens,damaging their cell membranes.The protein content in the body of the two pathogenic bacteria could be increased by the treatment with various concentrations of Trichokonins.The cell membranes of the two pathogens were constricted.The results of pot experiment showed that the disease index and morbidity were generally decreased after corning mycin root irrigation,and the effect was significant.5.Study on the growth promoting effect of Trichokonins on lily.The growth and physiological conditions of lily plants treated with different concentrations of Trichokonins were studied by root irrigation.The results showed that Trichokonins could effectively control lily root rot.The low concentration of Trichokonins?0.2mg/L⁰.4mg/L?could promote the growth of lily plants,effectively improve the plant height,flower diameter,adjust root to crown ratio,effectively protect the integrity of lily cell membrane,and improve the level of chlorophyll and soluble sugar and soluble protein content.The activity of SOD,SOD and peroxidase were increased and the peroxidation of plant was decreased.