Resource Of Fungal Parasites Of Root-knot Nematode And Study On Paecilomyces Lilacinus Strain PL89

Surveied the fungal parasites of the root-knot nematode (RKN) in 9 counties (cities) of Fujian province and 888 isolates of fungal parasites were obtained from females, eggs and egg masses of the RKN. These isolates belonged to 26 genera, 18 species and 3 varieties of them were identified. Pochonia chlamydosporia, Paecilomyces lilacinus , Fusarium solani, F. oxysporum were the dominant populations in the fungal parasites from the RKN and the frequency of their appearance was respectively taking up 22.30%, 19.14%, 17.23% and 9.57% of all the isolates. Pochonia chlamydosporia and Paecilomyces lilacinus were usually potential to control plant parasitic nematodes. 143 strains P. chlamydosporia var. chlamydosporia and 32 strains P. chlamydosporia van catenulata were identified by morphological characters observed through light microscopy among 175 strains P. chlamydosporia and P. chlamydosporia var. chlamydosporia was the dominant variety.Five strains (PL89, 021117-77, 021029-27, 021020-65 and 21020-36) with highest abilities of producing chitinases and highest pathogenicity to eggs of the RKN in vitro were obtained from 123 strains of Paecilomyces lilacinus through the model "screened by chitin culture media, the abilities of producing chitinase and pathogenicity to the eggs of RKN in vitro". Five strains with highest abilities of producing extracellular proteases and highest abilities of producing chitinases were obtained from 175 strains of Pochonia chlamydosporia through testing the extracellular proteases activity in gelatin agar substrate and the chitinase activity in chitin agar substrate. And the five stains P. chlamydosporia was 010727-1,021020-30,021120-48,021020-34 and 021120-81.Fermentation biology characteristics tests showed that the best ratio of C/N was 5:1 in liquid fermentation for strain PL89 and 20:1 was the best the ratio of C/N for sporulation in solid fermentation. 1 mol·L^-1 of carbon source was propitious to sporulate quickly in liquid fermentation, and the best concentration of carbon source for sporulation was 0.5 mol·L^-1 in solid fermentation. The best carbon source for increasing biomass and sproulation of the strain PL89 was starch soluble which was the most complex one among 5 carbon source (sucrose, maltose, glucose, lactose and starch soluble) , and the best nitrogen source for increasing biomass and sproulation was yeast extract which was organic nitrogen source. Absence of the macroelement could significantly reduce sporulation of strain PL89. The reducing percentages of sporulation absence of P, S and Mg were 90.8%, 90.6% and 83.1% respectively in liquid fermentation and reducing percentages of sporulation was 83.6%, 59.8% and 58.8% respectively in solid fermentation. Tests indicated that the strain PL89 was sensitive to microelement copper and aluminum but a given concentration of microelement manganese, magnesium and boron could increase the sporulation and the mycelial growth significantly in liquid fermentation. A given concentration of vitamin B₆ and folacin could significantly increase the sporulation of the strain PL89 in liquid fermentation.