| Banana Fusarium wilt, Fusarium oxysporum f.sp.cubense, is a destructive soil-borne disease andcaused a serious demage for banana production. The research of the inhibition against Fusarium wilt ofbiocontrol fungi Paecilomyces lilacinus (Thom.)Samson, the control effect of this fungi and microbialfertilizer against Fusarium wilt were carried out and its agent was developed in this paper.P.lilacinus had strong inhibitory effect against Fusarium oxysporum f.sp.cubense at differentconditions, including pH, ultraviolet times, NaCl concentrations, etc. P.lilacinus in40℃condition for30min the inhibitory effect against Fusarium oxysporum f.sp.cubense FJAT-3076and FJAT-370reached84.38%and85.68%respectively. But at60℃condition only a partial kept inhibitory effect and at85℃or105℃conditions almost lost its inhibitory effect.The fermentation liquid of P.lilacinus was analyzed by the GC-MS to get the basic informationabout the composition of secondary metabolic of the fugus in different period. From those, a total of25high match rates secondary metabolic were isolated and indentified, mainly including seventeenalkanes, two benzenes, two hydroxybenzenes, one olelins, one propionitriles, one esters and onecarboxylic acids. Alkanes occupied most in the fermentation liquid during the116-228h.P.lilacinus was fermented and grew at stroma cusion material added with rice bran, peanut powder,rice powder, sweet potato powder, flour, potato starch, rapeseed powder. Among those, when20%sweet potato powder was added to the stroma cusion material, the ferment capacity of P. lilacinus wasthe strongest. The initial viable fungi number from1.0×106cfu/g increased to7.5×108cfu/g through8days fermentation. P.lilacinus was well preserved in the microbial fertilizer at4℃and roomtemperature, it was preserved best in the microbial fertilizer contains30%and50%of water.Sodium alginate method was the best way to embe P.lilacinus and its best solidifyed temperaturewas4℃.Single factor experiment showed that the best solidifyed time for sodium alginate embed P.lilacinus was2h, the best inoculation amount was25%, the best sodium alginate concentration was5%and the best concentration of CaCl2was12%. In Czapek's medium fermented7days increased itsviable fungi number. The sodium alginate embedding method had a good protection and proliferationeffect for P. lilacinus, and its viable cell number from2.63×107cfu/g increased stably to5.50×107cfu/gunder4℃refrigerator for60days.The control efficiency of P.lilacinus and its microbial fertilizer against the Fusarium wilt in pottedbanana plants were reached to78.67%and72.84%. They significantly promoted the growth of bananaroots, stems and leaves. When15%,30%,45%of the microbial fertilizer contained with in total of thesoil, they all had the same promotive effects to the banana roots, stems and leaves, which containedwith15%had the best effects. P.lilacinus could colonize in the rhizosphere soil and root foundation soilof banana roots, but failed in occuring inside the banana roots, stems and leaves. P. lilacinus and its microbial fertilizer could enhance the activity level of PPO and SOD in banana plant, but POD stayedthe same.P.lilacinus and its microbial fertilizer could improve the activity of chitinase, urease and catalase inthe soil around banana roots. P. lilacinus microbial fertilizer treatment group and control group haddetected45different PLFAs mark in different time. Overall, amount of microganisms, bacteria, fungaland simpon, abundance index and diversity index of treatment group were greater than the control. |
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