| Cotton Verticillium wilt is a kind of soilborne vascular wilt disease caused byVerticillium dahliae, which seriously affects cotton yield and fiber varieties. CottonVerticillium wilt in China is caused by Verticillium dahliae Kleb, has outbroken repeatedlyand given rise to huge economic loss. V. dahliae microsclerotia are major primary infectionsource of cotton Verticillium wilt, and could survive in soil for many years without hosts.Lacking of effective germplasm resources resistant to disease, soil fumigant, crop rotation,fallow and some tillage measures were taken to control cotton Verticillium wilt in production.However, the effect is not good. Soil fumigation by agriculture chemical exists someproblems such as chemical residues, drug resistance, environment pollution. Biofumigationcould control some soilborne diseases effectively, improve soil organic matter content,increase fertility, improve soil structure, and friendly to environment. It has no phytotoxicityon plants, is regarded as a environmental soilborne disease control strategy which hasdevelopment prospect. Botanical pesticide which has low toxicity, low residue, little impacton the environment, has become the hot spot of plant diseases control, the research anddevelopment of botanical fungicide have broad prospects. Based on the previous results, wecarried out the further study of control efficiency of Chinese chives (Allium tuberosum), mint(Mentha arvensis), ageratum (Agastache rugosa) residues on cotton Verticillium wilt and theeffect of three plant residues on V. dahliae survival in soil, separated and identified theantifungal substances from Chinese chives extracts with antifungal activity test. We expectthat these plant residues could be used for biofumigation to control cotton Verticillium wilt, toprovide reference for the development of new botanical fungicide. The main research resultsare as follows:1. Chinese chives residue has good control efficiency on cotton Verticillium wilt.Chinese chives, mint, ageratum residues all reduced the disease index of cotton Verticilliumwilt and the amount of V. dahliae survival in soil. The control efficiency of Chinese chiveswas the best, followed by ageratum and mint. Cotton plant amended with Chinese chivesresidue treatments and inoculated with V. dahliae inoculum of0.5%,1.0%mass fraction of soil did not show symptom at12th week after seeding. The disease index of cotton plantsamended with ageratum residue treatments and inoculated with the same inoculumconcentration were1.06、2.08, which were significantly lower than29.17,37.22of control.2. Chinese chives, mint, ageratum residues have a certain effect on promoting growth ofcotton plant. Mint residue could increase the height and biomass of cotton plant significantly.In the V. dahliae inoculum concentration of1.0%、2.0%、4.0%、8.0%, the cotton plant heightof mint residue treatment were25.60,24.69,27.82,23.99cm, which were significantly higherthan18.57、19.71、17.05、16.46cm of control; The biomass of mint residue treatment were2.56、2.30、2.18、2.75g, which were significantly higher than2.20、1.95、1.84、1.28g ofcontrol.3. Antifungal activity components of Chinese chives methanol extract were found inpetroleum ether and ethyl acetate extractants. This two kinds of extract were pooled, andseparated by silica gel column chromatography. Nine fractions among of21fractions werefound to have high antifungal rate of100%. The main substances detected by GC-MS fromthe nine fractions were sulfides, alkenyl, aldehydes, alcohols, heterocyclic compounds, ferulicacid derivatives and squalene. The squalene and ferulic acid methyl ester with fungistasisactive to V. dahliae were first detected from Chinese chives.Chinese chives residue and its extracts could effectively inhibit V. dahliae and controlcotton Verticillium wilt, is a new kind of biofumigation material. The results providetheoretical basis for controlling cotton Verticillium wilt by these plant residues asbiofumigation material, also provide reference for research and development of new botanicalfungicide. |
PDF Full Text Request