Heat Stability of Resistance to Southern Root-knot Nematode in Bell Pepper Genotypes Homozygous and Heterozygous for the N Gene

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.

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Controlling the southern root-knot nematode (Meloidogyne incognita Chitwood) with grafted and resistant pepper varieties

International Journal of Horticultural Science ◽

10.31421/ijhs/16/2/881 ◽

2010 ◽

Vol 16 (2) ◽

Author(s):

Z. Mándoki

Keyword(s):

Meloidogyne Incognita ◽

Control Method ◽

Environmentally Friendly ◽

Bell Pepper ◽

N Gene ◽

Root Knot Nematode ◽

Resistant Varieties ◽

Environmentally Safe ◽

Resistant Rootstock ◽

Southern Root Knot Nematode

Newly bred resistant bell pepper varieties and those grafted onto resistant rootstock s were tested in soil severely infested with southern root-knot nematode [Meloidogy11e incognita (Kofoid and White) Chitwood] in unheated plastic house and compared to varieties on their own roots, in order to evaluate the efficiency of this environmentally friendly control method. 'Cinema F I ' carrying the N gene yielded significantly more than the two susceptible varieties. Varieties grafted onto resistant rootstocks outyielded those on their own roots although to different extent, which was not always significant. At the end of the vegetat ion period the roots of the rootstocks were undamaged and the roots of some resistant varieties were slightly infected. whereas the roots of susceptible varieties were severely damaged. According to our result . both the use of resistant varieties and grafted plants offer an effective and environmentally safe way of controlling M. incognita.

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Modified Expression of the N Gene for Southern Root-knot Nematode Resistance in Pepper at High Soil Temperatures

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.123.6.1012 ◽

1998 ◽

Vol 123 (6) ◽

pp. 1012-1015 ◽

Cited By ~ 17

Author(s):

Judy A. Thies ◽

Richard L. Fery

Keyword(s):

Cropping Systems ◽

N Gene ◽

Egg Mass ◽

Root Knot Nematode ◽

Partial Loss ◽

Resistant Cultivars ◽

High Soil ◽

Loss Of Resistance ◽

Soil Temperatures ◽

Southern Root Knot Nematode

Heat stability of the N gene that confers resistance to the southern root-knot nematode, Meloidogyne incognita (Kofoid & White) Chitwood in pepper (Capsicum annuum L.), was determined at 24, 28, and 32°C. Responses of resistant bell pepper cultivars Charleston Belle and Carolina Wonder (homozygous for the N gene) and their respective susceptible recurrent backcross parents, `Keystone Resistant Giant' and `Yolo Wonder B', to M. incognita were compared. Numbers of eggs/g fresh root, reproductive factor of M. incognita, numbers of second-stage juveniles in soil, egg mass production, and root galling increased (P < 0.05) for all cultivars as temperature increased. The response of the resistant cultivars to temperature increase was less dramatic than the response of the susceptible cultivars. Both `Charleston Belle' and `Carolina Wonder' exhibited a partial loss of resistance at 28 and 32 °C. Reproduction of M. incognita was minimal on the resistant cultivars at 24 °C, but increased at higher temperatures. However, at 32 °C reproduction of M. incognita on the resistant cultivars was only 20% of that on the susceptible cultivars and root gall indices were within the range considered moderately resistant. Unlike the susceptible cultivars, the shoot dry weights of the resistant cultivars were not suppressed at 32 °C. This suggests that `Charleston Belle' and `Carolina Wonder' may be somewhat tolerant to M. incognita at high soil temperatures. Although results indicate a partial loss of resistance occurred in `Charleston Belle' and `Carolina Wonder' under high soil temperatures, resistant cultivars may be a useful component of cropping systems designed to manage M. incognita in hot climates.

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Development of Bell Peppers with Resistance to the Southern Root-knot Nematode

HortScience ◽

10.21273/hortsci.32.4.600c ◽

1997 ◽

Vol 32 (4) ◽

pp. 600C-600

Author(s):

R.L. Fery ◽

P.D. Dukes ◽

J.A. Thies

Keyword(s):

Field Tests ◽

Field Evaluation ◽

Nematode Resistance ◽

The United States ◽

Bell Pepper ◽

Root Knot Nematode ◽

Bell Peppers ◽

Major Pest ◽

Southern Root Knot Nematode ◽

Homozygous Resistant

The southern root-knot nematode (Meloidogyne incognita) is a major pest of bell peppers (Capsicum annuum) in the United States. Since none of the leading bell pepper cultivars grown in the U.S. exhibit adequate levels of resistance, a breeding program was initiated to incorporate the N root-knot nematode resistance gene into commercial bell pepper germplasm. A backcross breeding procedure was used. The donor parent of the N gene was the open-pollinated, pimiento pepper cultivar Mississippi Nemaheart, and the recurrent parents were the open-pollinated bell pepper cultivars Keystone Resistant Giant and Yolo Wonder. A large number of homozygous resistant BC6 populations were evaluated in field tests in 1995, and two lines (PA-440, an isoline of `Keystone Resistant Giant', and PA-453, an isoline of `Yolo Wonder') were selected for further field evaluation and seed multiplication in 1996. Results of replicated field and greenhouse tests conducted in 1996 indicate that root-knot nematode resistance has been incorporated successfully in `Keystone Resistant Giant' and `Yolo Wonder' backgrounds.

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Host Resistance and Metam Sodium for Managing Root-knot Nematodes in a Pepper–Cucumber Rotation

HortScience ◽

10.21273/hortsci.40.7.2080 ◽

2005 ◽

Vol 40 (7) ◽

pp. 2080-2082 ◽

Cited By ~ 3

Author(s):

Judy A. Thies ◽

Richard F. Davis ◽

John D. Mueller ◽

Richard L. Fery ◽

David B. Langston ◽

...

Keyword(s):

Drip Irrigation ◽

Irrigation System ◽

Bell Pepper ◽

Recurrent Parent ◽

Drip Irrigation System ◽

Root Knot Nematode ◽

Nematode Reproduction ◽

Metam Sodium ◽

Southern Root Knot Nematode ◽

Treatment Application

Root-knot nematode-resistant `Charleston Belle' bell pepper (Capsicum annuum L. var. annuum) and metam sodium treatment were evaluated for managing the southern root-knot nematode [Meloidogyne incognita (Chitwood) Kofoid and White] in fall-cropped cucumber (Cucumis sativus L.). `Charleston Belle' and its susceptible recurrent parent, `Keystone Resistant Giant', were planted as spring crops at Blackville, S.C., and Tifton, Ga. `Charleston Belle' exhibited high resistance and `Keystone Resistant Giant' was susceptible at both locations. After termination of the bell pepper crop, one-half of the plots were treated with metam sodium delivered through the drip irrigation system. Cucumber yields and numbers of fruit were highest for cucumber grown in plots treated with metam sodium following either `Charleston Belle' or `Keystone Resistant Giant'; however, root gall severity and numbers of M. incognita eggs in the roots were lowest for cucumber grown in plots treated with metam sodium following `Charleston Belle'. Conversely, root gall severity and nematode reproduction were highest for cucumber grown in plots following `Keystone Resistant Giant' without metam sodium treatment. Application of metam sodium through the drip irrigation system following a spring crop of root-knot nematode-resistant bell pepper should reduce severity of root galling and reproduction of M. incognita as well as increase fruit yield of fall-cropped cucumber.

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Characterization of New Sources of Resistance in Cowpea to the Southern Root-knot Nematode

HortScience ◽

10.21273/hortsci.29.6.678 ◽

1994 ◽

Vol 29 (6) ◽

pp. 678-679 ◽

Cited By ~ 8

Author(s):

Richard L. Fery ◽

Philip D. Dukes ◽

Judy A. Thies

Keyword(s):

Egg Production ◽

Nematode Resistance ◽

Field Studies ◽

Egg Mass ◽

Root Knot Nematode ◽

Sources Of Resistance ◽

Dominant Type ◽

Plant Introductions ◽

Nematode Resistance Gene ◽

Southern Root Knot Nematode

A series of greenhouse and field studies was conducted over 9 years to characterize three new sources of resistance in cowpea [Vigna unguiculata (L.) Walp.] to the southern root-knot nematode [Meloidogyne incognita (Kofoid & White) Chitwood] and to determine if the resistances are conditioned by genes allelic to the Rk root-knot nematode resistance gene in `Mississippi Silver'. Three plant introductions (PI), PI 441917, PI 441920, and PI 468104, were evaluated for reaction to M. incognita in four greenhouse tests, and in every test each PI exhibited less galling, egg mass formation, or egg production than `Mississippi Silver'. F2 populations of the crosses between `Mississippi Silver' and each of the three resistant PIs were also evaluated for root-knot nematode resistance in a greenhouse test. None of the F2 populations segregated for resistance, indicating that PI 441917, PI 441920, and PI 468104 each has a gene conditioning resistance that is allelic to the Rk gene in `Mississippi Silver'. Our observations on the superior levels of resistances exhibited by PI 441917, PI 441920, and PI 468104 suggest that the allele at the Rk locus in these lines may not be the Rk allele, but one or more alleles that condition a superior, dominant-type resistance. The availability of additional dominant alleles would broaden the genetic base for root-knot nematode resistance in cowpea.

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Stability of Resistance to Root-knot Nematodes in ‘Charleston Belle’ and ‘Carolina Wonder’ Bell Peppers in a Sub-tropical Environment

HortScience ◽

10.21273/hortsci.43.1.188 ◽

2008 ◽

Vol 43 (1) ◽

pp. 188-190 ◽

Cited By ~ 9

Author(s):

Judy A. Thies ◽

Don W. Dickson ◽

Richard L. Fery

Keyword(s):

Methyl Bromide ◽

Meloidogyne Incognita ◽

Bell Pepper ◽

Root Knot Nematode ◽

Nematode Reproduction ◽

Tropical Environments ◽

Bell Peppers ◽

Stability Of Resistance ◽

Soil Temperatures ◽

Southern Root Knot Nematode

Two root-knot nematode-resistant bell pepper cultivars, ‘Charleston Belle’ and ‘Carolina Wonder’ (Capsicum annuum L. var. annuum], and their susceptible parents, ‘Keystone Resistant Giant’ and ‘Yolo Wonder B’, were compared for managing the southern root-knot nematode [Meloidogyne incognita (Chitwood) Kofoid and White] in fall and spring tests at Citra, FL. In the fall test, ‘Charleston Belle’ and ‘Carolina Wonder’ exhibited minimal root galling and nematode reproduction, and ‘Keystone Resistant Giant’ and ‘Yolo Wonder B’ exhibited severe root galling and high nematode reproduction. Fruit yield of ‘Charleston Belle’ was 97% greater than yields of the two susceptible cultivars (P ≤ 0.006). In the spring test, one-half of the plots were treated with methyl bromide/chloropicrin before planting the same four bell pepper cultivars. ‘Keystone Resistant Giant’ and ‘Yolo Wonder B’ grown in untreated control plots exhibited severe root galling and high nematode reproduction, but the other six cultivar × methyl bromide combinations exhibited minimal root galling and nematode reproduction. Although soil temperatures (10-cm depth) were greater than 30 °C on 78 days and 57 days during the Fall 2002 and Spring 2003 trials, respectively, resistance did not break in ‘Charleston Belle’ and ‘Carolina Wonder’ in either test. These results demonstrate that root-knot nematode-resistant cultivars such as Charleston Belle and Carolina Wonder are viable alternatives to methyl bromide for managing southern root-knot nematode in bell pepper in sub-tropical environments.

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Response of Bell Pepper Cultivars Near-isogenic for the N Gene to Meloidogyne incognita in Field Trials

HortScience ◽

10.21273/hortsci.38.7.1394 ◽

2003 ◽

Vol 38 (7) ◽

pp. 1394-1396 ◽

Cited By ~ 3

Author(s):

Judy A. Thies ◽

Richard L. Fery ◽

John D. Mueller ◽

Gilbert Miller ◽

Joseph Varne

Keyword(s):

Meloidogyne Incognita ◽

Field Tests ◽

Nematode Resistance ◽

Field Studies ◽

Field Trials ◽

Bell Pepper ◽

N Gene ◽

Root Knot Nematode ◽

High Level ◽

Fresh Root

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.

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Double-Cropping Cucumbers and Squash After Resistant Bell Pepper for Root-Knot Nematode Management

Plant Disease ◽

10.1094/pdis.2004.88.6.589 ◽

2004 ◽

Vol 88 (6) ◽

pp. 589-593 ◽

Cited By ~ 20

Author(s):

Judy A. Thies ◽

Richard F. Davis ◽

John D. Mueller ◽

Richard L. Fery ◽

David B. Langston ◽

...

Keyword(s):

Cucumis Sativus ◽

Meloidogyne Incognita ◽

Cucurbita Pepo ◽

Cropping Systems ◽

Bell Pepper ◽

Recurrent Parent ◽

Root Knot Nematode ◽

Nematode Reproduction ◽

Double Cropping ◽

Southern Root Knot Nematode

‘Charleston Belle’, a root-knot nematode-resistant pepper (Capsicum annuum var. annuum [Grossum Group]), and its susceptible recurrent parent, ‘Keystone Resistant Giant’, were compared as spring crops for managing the southern root-knot nematode (Meloidogyne incognita) in fall-cropped cucumber (Cucumis sativus) and squash (Cucurbita pepo) at Blackville, SC and Tifton, GA. ‘Charleston Belle’ exhibited minimal root galling and nematode reproduction, and ‘Keystone Resistant Giant’ exhibited severe root galling and high nematode reproduction. Cucumber grown in plots following ‘Charleston Belle’ had lower (P ≤ 0.001) root gall severity indices than following ‘Keystone Resistant Giant’ (4.2 versus 4.9, respectively). Cucumber yields were 87% heavier (P ≤ 0.0001) and numbers of fruit were 85% higher (P ≤ 0.0001) in plots previously planted to ‘Charleston Belle’ than to ‘Keystone Resistant Giant’. Squash grown in plots following ‘Charleston Belle’ had lower (P ≤ 0.001) root gall severity indices than following ‘Keystone Resistant Giant’ (4.0 versus 4.8, respectively). Squash yields were 55% heavier (P ≤ 0.01) and numbers of fruit were 50% higher (P ≤ 0.001) in plots previously planted to ‘Charleston Belle’ than to ‘Keystone Resistant Giant’. These results demonstrate that root-knot nematode-resistant bell pepper cultivars such as ‘Charleston Belle’ are useful tools for managing M. incognita in double-cropping systems with cucurbit crops.

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First Report of the Root-Knot Nematode, Meloidogyne floridensis, on Tomato in Georgia, USA

Plant Disease ◽

10.1094/pdis-10-20-2286-pdn ◽

2020 ◽

Author(s):

Josiah Marquez ◽

Fereidoun Forghani ◽

Abolfazl Hajihassani

Keyword(s):

South Carolina ◽

Mass Culture ◽

Prunus Persica ◽

Large Subunit ◽

N Gene ◽

Egg Mass ◽

Vegetable Crops ◽

Root Knot Nematode ◽

First Report ◽

Tomato Field

Meloidogyne floridensis, also known as the peach root-knot nematode (RKN), is a new emerging species found to break crop host-resistance to M. incognita (Stanley et al. 2009). It was first described from Florida (Handoo et al. 2004) parasitizing M. incognita-resistant rootstock cultivars of peach (Prunus persica), and tomato (Solanum lycopersicum) (Church 2005). The nematode has recently been reported in California’s almond orchards (Westphal et al. 2019) and peach rootstock (cv. Guardian) in South Carolina (Reighard et al. 2019). In a 2018 survey of vegetable fields sampled randomly in South Georgia, RKN was found with a high density (5,264 second-stage juveniles (J2)/100 cm3 of soil) from a tomato field in Ware County, GA. The soil sample consist of 30 soil cores sampled at 20-cm depth across the field in a zig-zag motion. To perform Koch’s postulate, 2,000 eggs from a single egg-mass culture were inoculated into deepots filled with mixture of sand and sterilized field soil (1:1 v/v) and grown with tomato cv. Rutgers for 60 days in the greenhouse. A reproduction factor of 21.1 ± 6.1 was obtained confirming the nematode parasitism on tomato (Fig. 1S). For molecular identification, DNA was extracted by smashing three individual females isolated from the galled roots in 50 µl sterile distilled water, followed by a freeze-thaw (95°C, 1 min). Results of PCR analyzes by species-specific primers (Fjav/Rjav, Finc/Rinc and Far/Rar) did not detect the nematode species (Zijlstra et al. 2000). PCR products were obtained and sequenced from two primer sets consisting of the forward NAD5F2 (5’-TATTTTTTGTTTGAGATATATTAG-3’) and the reverse NAD5R1 (5’-CGTGAATCTTGATTTTCCATTTTT-3’) for amplification of a fragment of the NADH dehydrogenase subunit 5 (NADH5) gene (Janssen et al. 2016), and the forward TRANH (5’-TGAATTTTTTATTGTGATTAA-3’) and the reverse MRH106 (5’-AATTTCTAAAGACTTTTCTTAGT-3’) for amplification covering a portion of the cytochrome c oxidase subunit II (COII) and large subunit 16SrDNA (16S) gene (Stanton et al. 1997). DNA sequence of NADH5 gene fragment (accession no. MT795954) was 100% identical (532/532 bp) with a M. floridensis isolate from California and South Carolina (accession no. MH729181 and MN072363), while fragment of the COII and 16S genes (accession no. MT787563) was 99.76% identical (421/422 bp) with an isolate from Florida (accession no. DQ228697). The nematode females were also used for morphometric and perennial pattern analysis. Several micrographs with the inverted microscope (ZEISS Axio Vert.A1, Germany) and camera (ZEISS Axiocam 305 color, Germany) were taken from ten J2s for mean, standard deviation and range of body length: 362.7 ± 11.2 (340.4-379) µm, maximum body width: 15 ± 1.3 (12.4-16.4) µm, stylet length: 12.3 ± 1.3 (9.5-14) µm, hyaline tail terminus: 8.9 ± 1.1 (7.5-10.9) µm and tail length: 35.7 ± 4.4 (28.5-39.5) µm. Morphological measurements and configuration of perineal patterns (Fig. 2S) were comparable to previous reports of M. floridensis isolates from Florida (Handoo et al. 2004; Stanley et al. 2009). To the best of our knowledge, this is the first report of M. floridensis in Georgia as the fourth state in the USA after South Carolina, California and Florida. This nematode has been reported to parasitize several vegetable crops, including cucumber, eggplant, tomato, snap bean and squash. Furthermore, RKN resistant cultivars of tomato (harboring Mi-1 gene), pepper (harboring N gene), corn cv. Mp-710 and tobacco cv. NC 95 have been found susceptible to M. floridensis (Stanley et al. 2009), making it a serious threat.

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