Response of meloidogyne hapla to mycorrhiza fungi inoculation on pyrethrum

Five arbuscular mycorrhiza fungi (AMF) isolated from pyrethrum were screened in the greenhouse for efficacy in improving pyrethrum growth and in suppressing a root-knot nematode, Meloidogyne hapla. The fungi screened were Glomus spp. (isolates LM61, ML34 and ML35), Scutellospora sp. (isolate KS74) and Gigaspora sp. (isolate LM83). A 20g mixed fungal inoculum was incorporated into sterilized sand-soil mixture before transplanting 6-week-old pyrethrum seedlings. The inoculum consisted of the growth medium, spores, external mycelia and infected rootsegments. The plants were inoculated with 6000 M. hapla second stage juvenile (J-2) 3 months after fungal inoculation. Dry shoot weights, fresh root weights, percent root colonization by the fungi, nematode gall indices, number of eggs and females in the root system and number of J-2 in the soil were determined at the end of the experiment, two months after nematode inoculation. Glomus LM61 and Scutellospora KS74 significantly improved top biomasses of fungus-treated and fungus-nematodetreatedplants. Glomus LM61was more effective (33% top biomass increase). Glomus ML34 and ML35 and Gigaspora LM83 improved top biomasses of fungus-nematode-treated plants. Scutellospora KS74 and Glomus ML34 significantly increased fresh root weights of pyrethrum by 45% and 50%, respectively. Glomus LM61, Scutellospora KS74 and Gigaspora LM83 caused 86%, 32% and 37% nematode suppression, respectively. All the fungal isolates significantly reduced the number of females and J-2. The presence of nematodes in fungus-treated plants did not affect rootcolonization by the fungi except in plants treated with Glomus ML34 and ML35

Suppression of root-knot nematode by mycosymbionts on pyrethrum (Chrysanthemum cinerariefolium Vis.)

Five arbuscular mycorrhiza fungi (AMF) obtained from pyrethrum fields were screened for efficacy in improving pyrethrum (Chrysanthemum cinerariefolium Vis.) growth and in suppressing a root-knot nematode, Meloidogyne hapla Chitwood in the greenhouse. The fungi screened were Glomus macrocarpum Tul and Tul, G. constrictum Trappe, G. monosporum Gerd. & Trappe, Scutellospora calospora (Nicol. Gerd.) Walker & Sanders and Gigaspora gigantea (Nicol. Gerd.) Gerd. & Trappe. A mixed fungal inoculum was incorporated into sterilized sand-soil mixture before transplanting 6-week-old pyrethrum seedlings. The inoculum consisted of the growth medium, spores, external mycelia and infected root segments. The plants were inoculated with 6000 M. hapla second stage juvenile (J-2) 3 months after fungal inoculation. Dry shoot weights, fresh root weights, percent root colonization by the fungi, nematode gall indices, number of eggs and females in the root system and number of J-2 in the soil were determined at the end of the experiment, 2 months after nematode inoculation. Glomus macrocarpum and S. calospora significantly improved top biomasses of fungus-treated and fungusnematode- treated plants. Glomus macrocarpum was the most effective, causing a 35% top biomass increase. Glomus constrictum, G. monosporum and G. gigantea improved top biomasses of fungusnematode- treated plants. Scutellospora calospora and G. constrictum significantly increased fresh root weights of pyrethrum by 46% and 53%, respectively. Except G. constrictum and G. monosporum, all the other fungi suppressed M. hapla disease severity and egg production. Glomus macrocarpum was the most effective, causing 87% nematode suppression. Scutellospora calospora and Gigaspora gigantea suppressed disease severity and egg production by up to 33% and 37%, respectively. All the fungi significantly reduced the number of females and J-2 in pyrethrum roots. Nematodes did not affect root colonization by the fungi except in G. constrictum and G. monosporum-colonized plants. Key Words: Gigaspora gigantea, Glomus macrocarpum, G. constrictum, G. monosporum, Meloidogyne hapla, pyrethrum, Scutellospora calospora, suppression J. Trop. Microbiol Vol.1 2002: 64-7

Tomato growth and fungal parasitism of Meloidogyne javanicaeggs as affected by nematicides, time of harvest, and intercropping

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