Search Results

You are looking at 1 - 10 of 16 items for :

  • "Meloidogyne incognita race 3" x
  • All content x
Clear All
Free access

Sindynara Ferreira, Luiz Antonio A. Gomes, Wilson Roberto Maluf, Vicente Paulo Campos, José Luiz S. de Carvalho Filho, and Daniela Costa Santos

This study assessed the reaction of dry bean and snap bean cultivars to infection by Meloidogyne incognita (races 1, 3) and by Meloidogyne javanica, two species of root-knot nematodes. Three independent experiments were done, one for each species or race of Meloidogyne, using randomized complete block designs with four replications (plots) and four plants per plot. A plot with the susceptible tomato cultivar Santa Clara was used in each block to determine the efficiency of the inoculum and to calculate the reproduction rate for each of the genotypes assessed. The bean cultivars Aporé and Talismã were highly resistant to Meloidogyne javanica, slightly resistant to Meloidogyne incognita race 1, and moderately resistant and slightly resistant, respectively, to Meloidogyne incognita race 3. The snap bean cultivars Macarrão Atibaia and Macarrão Preferido were slightly resistant to Meloidogyne javanica and moderately resistant and susceptible, respectively, to Meloidogyne incognita race 1. The reactions of the latter cultivars against Meloidogyne incognita race 3 were very resistant and slightly resistant, respectively. The results of these experiments showed that the dry bean cultivars Aporé and Ouro Negro and the snap bean cultivar Macarrão Atibaia have potential to be used in breeding programs for a broader spectrum of root-knot nematode resistances.

Free access

Judy A. Thies, Richard L. Fery, John D. Mueller, Gilbert Miller, and Joseph Varne

Resistance of two sets of bell pepper [(Capsicum annuum L. var. annuum (Grossum Group)] cultivars near-isogenic for the N gene that conditions resistance to root-knot nematodes [Meloidogyne incognita (Chitwood) Kofoid and White, M. arenaria (Neal) Chitwood races 1 and 2, and M. javanica (Treub) Chitwood] was evaluated in field tests at Blackville, S.C. and Charleston, S.C. The isogenic bell pepper sets were `Charleston Belle' (NN) and `Keystone Resistant Giant' (nn), and `Carolina Wonder' (NN) and `Yolo Wonder B' (nn). The resistant cultivars Charleston Belle and Carolina Wonder were highly resistant; root galling was minimal for both cultivars at both test sites. The susceptible cultivars Keystone Resistant Giant and Yolo Wonder B were highly susceptible; root galling was severe at both test sites. `Charleston Belle' had 96.9% fewer eggs per g fresh root than `Keystone Resistant Giant', and `Carolina Wonder' had 98.3% fewer eggs per g fresh root than `Yolo Wonder B' (averaged over both test sites). `Charleston Belle' and `Carolina Wonder' exhibited a high level of resistance in field studies at both sites. These results demonstrate that resistance conferred by the N gene for root-knot nematode resistance is effective in field-planted bell pepper. Root-knot nematode resistant bell peppers should provide economical and environmentally compatible alternatives to methyl bromide and other nematicides for managing M. incognita.

Free access

Judy A. Thies and Richard L. Fery

Expression of the N gene, which confers resistance to southern root-knot nematode (Meloidogyne incognita Kofoid and White) in bell pepper [(Capsicum annuum L. var. annuum (Grossum Group)], is modified at high temperatures (28 °C and 32 °C), but its expression in the heterozygous condition (Nn) has not been documented at moderate or high temperatures. Responses of the near-isogenic bell pepper cultivars, Charleston Belle and Keystone Resistant Giant (differing at the N locus), and the F1 and reciprocal F1 crosses between these cultivars to M. incognita race 3 were determined at 24, 28, and 32 °C in growth chamber experiments. `Keystone Resistant Giant' (nn) was susceptible at 24, 28, and 32 °C. `Charleston Belle' (NN) exhibited high resistance at 24 °C and resistance was partially lost at 28 and 32 °C. However, at 32 °C root gall and egg mass severity indices for `Charleston Belle' were still in the resistant range, and the number of M. incognita eggs per gram fresh root and reproductive index were 97% and 90% less, respectively, than for `Keystone Resistant Giant'. Responses of the F1 and F1 reciprocal hybrid populations to M. incognita were similar to the response of the resistant parent at all temperatures. Root fresh weights and top dry weights indicated that both hybrid populations tolerated M. incognita infections at least as well as `Charleston Belle'. These findings indicate that i) only one of the parental inbred lines needs to be converted to the NN genotype to produce F1 hybrid cultivars with fully functional N-type resistance to M. incognita; and ii) cytoplasmic factors are not involved in expression of N-type resistance and the resistant parental inbred can used to equal advantage as either the paternal or the maternal parent.

Free access

A. G. Hunter and O. L. Chambliss

Screening for resistance to blackeye cowpea mosaic virus (BlCMV) and rootknot nematode on the same plant is possible if the two pathogens do not interact significantly. To determine if such interactions were present four cultivars were planted in 72-cell styrofoam flats, with a combination of BlCMV and nematode inoculations (--, -+, +-, and ++). `Freezegreen' is known to be susceptible to both pathogens, `Mississippi Silver' is resistant to both, `California Blackeye #5' is susceptible to BlCMV, and `Worthmore' is resistant to BlCMV. Nematode treated seeds were inoculated at planting with 2,000 eggs of (Meloidogyne incognita Race 3); BlCMV was inoculated on primary leaves a week later. Plants were visually rated for symptoms: either negative or positive for BlCMV and 1-5, no galls and heavily galled respectively, for rootknot. Analyses of variance using percentage of plants negative for virus symptoms or average nematode score as the dependent variable, resulted in non-significant virus × nematode interactions. Results by cultivar indicated simultaneous screening did not change their resistance/susceptible classifications.

Free access

Judy A. Thies and Amnon Levi

. citroides PIs that showed moderate resistance to M. arenaria race 1 for resistances to M. incognita race 3 and M. arenaria race 2. Materials and Methods Inocula. Meloidogyne incognita race 3 and M. arenaria race 2 were cultured on

Free access

Richard L. Fery and Judy A. Thies

Resistant Giant’ (susceptible control) plants grown in soil infested with the southern root-knot nematode, Meloidogyne incognita race 3 (Greenhouse Experiment, 2008). z The root-knot nematode-resistant ‘Truhart-NR’ is recommended for use by both home

Free access

Richard L. Fery and Judy A. Thies

-426 (Scotch Bonnet-type donor parent of resistance gene), PA-350 (susceptible Habanero-type recurrent parent), and TigerPaw-NR plants grown in soil infested with the southern root-knot nematode, Meloidogyne incognita race 3 (greenhouse experiment

Free access

Richard L. Fery and Judy A. Thies

) plants grown in soil infested with the southern root-knot nematode, Meloidogyne incognita race 3 (greenhouse experiment). z The root-knot nematode-resistant PA-559 is recommended for use as a parental line by pepper breeders interested in

Free access

Richard L. Fery and Judy A. Thies

) plants grown in soil infested with the southern root-knot nematode, Meloidogyne incognita race 3 (Greenhouse Experiment, 2008). z The root-knot nematode-resistant PA-566 is recommended for use as a parental line by pepper breeders interested in

Free access

Richard L. Fery and Judy A. Thies

) grown in soil infested with the southern root-knot nematode, Meloidogyne incognita race 3 (Greenhouse Experiment, 2006–2007). z The southern root-knot nematode-resistant PA-560 is recommended for use as a parental line by pepper breeders interested in