Effects of crop plants on abundance of Pochonia chlamydosporia and other fungal parasites of root-knot and potato cyst nematodes

Abstract

The effects of a host plant on reproduction/abundance of fungal populations in relation to soil nutrients released by plants in the rhizosphere were studied. Abundance in the soil and potato rhizosphere of the fungi Paecilomyces lilacinus, Monographella cucumerina (CABI 380408) and Pochonia chlamydosporia var. chlamydosporia (Pc280, potato cyst nematode biotype) and P. chlamydosporia var. catenulata (Pc392, root-knot nematode biotype) were assessed. The different ability of break crops (oilseed rape, sugarbeet and wheat) in the potato rotation to support Pa. lilacinus, Pochonia isolates Pc280 and Pc392 and abundance of the latter two isolates in soil and rhizosphere of potato plants infected with Meloidogyne incognita were also studied. Potato chits and crop seedlings were planted into boiling tubes containing 5000 chlamydospores or conidia g −1 in acid washed sand (pH 6) and kept in a growth chamber at 20 • C, and 16 h of light for up to 9 weeks. The abundance of the fungi in sand (fallow) differed significantly between fungal species, being in general less abundant in the absence than in the presence of the plant, although there was no interaction between plant species and fungal isolate. There was evidence of a different response to Me. incognita for Pc392 than for Pc280 but there was no significant effect of the presence of the nematode on the rate of increase of the fungus.

Observations on the effect of trophic conditions onPochonia chlamydosporiagene expression

“…Finally, the differences observed in the effects induced by the two P. chlamydosporia isolates on the growth performance of inoculated barley plants confirm previous observations on the diversity encountered among the populations of the fungus with different origins and their differential host and plant specialisations (Kerry, 2000;Siddiqui et al, 2009;Manzanilla-López et al, 2011).…”

Arabidopsis thalianaroot colonization by the nematophagous fungusPochonia chlamydosporiais modulated by jasmonate signaling and leads to accelerated flowering and improved yield

“…Pochonia chlamydosporia also acts as a true root endophyte in monocot and dicot plants (Bordallo et al ., ; Manzanilla‐López et al ., ; Escudero & Lopez‐Llorca, ). Moreover, previous results strongly suggest that P. chlamydosporia can promote plant growth of economically important crops such as barley and wheat (Monfort et al ., ; Macia‐Vicente et al ., ; Rosso et al ., ) as well as reduce flowering and fruiting times in tomato (Zavala‐González et al ., ).…”

Some isolates of the nematophagous fungusPochonia chlamydosporiapromote root growth and reduce flowering time of tomato

“…P . chlamydosporia colonises endophytically monocotyledon (Maciá‐Vicente et al , ; Lopez‐Llorca et al , ) and dicotyledon plant roots (Bordallo et al , ; Manzanilla‐López et al , ; Escudero & Lopez‐Llorca, ). This fungus has been shown to improve yields of infested nematode crops such as cotton (Wang et al , ), chilli (Singh et al , ), lemon (Deepa et al , ), potato (Muthulakshmi et al , ), okra (Chaya & Rao, ), eggplant (Khan et al , ), lettuce (Dias‐Arieira et al , ) and the ornamental plants tuberose ( Polyanthus tuberosa L.), hollyhock ( Althea rosea L.), petunia ( Petunia hybrid Vilm.)…”