EFECTO DE EXTRACTOS VEGETALES EN CRUDO EN EL PARASITISMO DE POCHONIA CHLAMYDOSPORIA VAR. CHLAMYDOSPORIA SOBRE MELOIDOGYNE INCOGNITA

Vichis-Martinez, K., R.H. Manzanilla-Lopez, S.J. Powers, and R. Montes Belmont. 2013. Effect of the addition of crude plant extracts on the parasitism of Pochonia chlamydosporia var. chlamydosporia on Meloidogyne incognita. Nematropica 43:254-260. Two assays were conducted to assess the effect of aqueous crude extracts from six plants with properties against nematodes (Argemone mexicana L., Chenopodium album L., Datura stramonium L., Raphanus raphanistrum L., Nerium oleander L. and Crotalaria ochroleuca G. Don.) on the parasitic activity of strains Pc10 and Pc341 of the nematophagous fungus Pochonia chlamydosporia var. chlamydosporia, a facultative parasite of Meloidogyne incognita eggs. In one of the assays, a suspension of nematode eggs (1000/ml) from infested tomato roots (Solanum lycopersicum L. var. Tiny Tim), a conidia suspension (5.5x10 4 /ml) of P. chlamydosporia (strain Pc10 or Pc341) plus an aliquot of plant extract (25%) were added to yeast extract liquid medium. The medium was incubated at 26°C and was shaken at 150 rpm for up to 48 hr. Results at 24 hr and 48 hr showed that the percentage of egg parasitism was reduced and was statistically different in all treatments. Crotalaria ochroleuca and N. oleander had the lowest and the highest percentage of parasitism, respectively. Results from a second assay carried out under greenhouse conditions using sterile soil in pots, to which, 10 egg masses and chlamydospores (5.5x10 4 /ml) were inoculated, and pots watered daily with aqueous plant crude extract (25%), showed that 12 days after inoculation there was an increase in parasitic fungus activity for all treatments.