COMBINATION OF ISOLATES OF Pochonia chlamydosporia FOR THE CONTROL OF Meloidogyne javanica IN TOMATO

Abstract

Three different isolates of Pochonia chlamydosporia (Pc-3, Pc-10 and Pc-28) were evaluated in a greenhouse experiment when applied individually and in combinations. A control treatment with no application of isolates of P. chlamydosporia var. chlamydosporia was included, while neither isolates nor nematodes were used in another untreated treatment. One-liter pots were filled with sterilized soil, and each pot was infested with 3 g of rice substrate colonized with the respective isolate plus 3,000 eggs of Meloidogyne javanica. One 'Santa Clara' tomato seedling was transplanted to each pot after fifteen days. None of the isolates (applied individually or in combinations) was able to reduce the number of galls when compared to the control treatment. However, the number of eggs of M. javanica decreased for isolates Pc-10 and mixtures Pc-10 + Pc-3, and Pc-10 + Pc-28 + Pc-3. The association of isolates of P. chlamydosporia var. chlamydosporia did not increase the control of M. javanica when compared to the application of Pc-10 individually.Key words: biological control, nematodes, nematophagous fungi, root-knot nematode. RESUMENEl experimento se realizó en invernadero, donde se evaluaron tres aislamientos de Pochonia chlamydosporia (Pc-3, Pc-10 y Pc-28), que se aplicaron individualmente y en combinaciones. En el tratamiento testigo no se aplicó P. chlamydosporia var. chlamydosporia al suelo, y también se incluyó un tratamiento testigo sin nematodos. Vasos de un litro de capacidad con suelo esterilizado fueron infestados con 3 g de sustrato de arroz colonizados con el respectivo aislamiento del hongo más 3.000 huevos de M. javanica. Quince días más tarde, se trasplantó en cada vaso una plántula de tomate 'Santa Clara'. Ninguno de los aislamientos del hongo, en forma individual o en mezcla, fueron capaces de reducir el número de agallas en comparación con el tratamiento testigo. Sin embargo, el número de huevos de M. javanica se redujo para el aislamiento Pc-10 y las combinaciones de Pc-10 + Pc-3 y Pc-10 + Pc-28 + Pc-3. La asociación de los aislamientos de P. chlamydosporia var. chlamydosporia no aumentó el control de M. javanica en comparación con la aplicación de Pc-10 individualmente.

Meloidogyne incognita and melon plants: host status, induced resistance and biological control

“…In agreement with this, similar reproduction was achieved in tomatoes evaluated 45 days after transplanting to pots, containing soil infested with 3000 eggs (Xavier et al 2017). Despite this reason, the low M. incognita development on the trial #1 did not invalidate or disqualify our data, since most results showed consistence in the other trials, except for P. chlamydosporia, which will be discussed separately.…”

“…Furthermore, the inoculated plants presented small young galls and the egg masses were not abundant, as on trial #2. Taking this into account, longer period was necessary to allow properly nematode development .Moreover, regarding the evaluation at 40 DAI, similar reproduction was achieved on tomatoes evaluated 45 days after transplanting to pots, containing soil infested with 3000 eggs (Xavier et al 2017). Despite the reason for the poor development, the nematode reproduction parameters of the trial #1 and #2 will be further discussed below.…”

Bionomics and the role of antinemic metabolites of the nematophagous fungus, Pochonia chlamydosporia in suppressing phytonematodes - A Comprehensive Review

“…Colonization and growth of P. chlamydosporia in soil was documented by several authors (LACR 1991, Bontempo et al, 2014, Xavier et al, 2017 (Plate 2a). Abundant growth was observed when P. chlamydosporia was inoculated in the soil as only hyphal fragments and chlamydospores without any food base than applied as colonized sand bran.…”

“…P. chlamydosporia has high ability to colonize the rhizosphere and the persistence was about 10 weeks on tomato rhizosphere. Single or individual isolate treatment of P. chlamydosporia in soil resulted in improved M. javanica control on tomato (Xavier et al, 2017, Coutinho et al, 2021. The application of fungus before planting in the rhizosphere resulted in 50% of infected eggs, 25% reduction of multiplication and root galling of root knot nematode (Affokpon et al, 2015).…”

Recent Advances in the Development of Environmentally Benign Treatments to Control Root-Knot Nematodes

“…In contrast, the effect of three P. chlamydospora isolates (Pc-3, Pc-10, and Pc-28) for the control of M. javanica on tomato was not promising ( Xavier et al., 2017 ) as none of the isolates were able to reduce gall severity whether applied individually or in combination. However, the number of eggs was decreased in comparison to the control for isolate Pc-10 and the mixtures Pc-10 + Pc-3 and Pc-10 + Pc28 + Pc-3.…”