Efficient Evaluation of Resistance to Three Root-knot Nematode Species in Selected Sweetpotato Cultivars

Five sweetpotato [Ipomoea batatas (L.) Lam.] cultivars (`Beauregard', `Excel', `Jewel', `Hernandez', and `Porto Rico') were evaluated for resistance to three root-knot nematode species: Meloidogyne arenaria (Neal) Chitwood (race 2), M. incognita (Kofoid & White) Chitwood (race 3), and M. javanica (Treub) Chitwood. Resistance screening efficiency was assessed in both 400-cm3 square pots and 150-cm3 Conetainers™. Nematode infection was assessed as the percentage of root system galled, percentage of root system necrosis, and the number of nematode eggs produced per gram of root tissue. Means of these dependent variables were not different (P ≤ 0.05) between container types, with Conetainers™ being more efficient to use. Root necrosis was not related to nematode infection, but was significant among cultivars (P = 0.0005). The resistance responses of the cultivars differed depending on the nematode species. All five cultivars were resistant to M. arenaria race 2. `Hernandez', `Excel', and `Jewel' were also resistant to M. incognita race 3 and M. javanica.

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Evaluation of Sweetpotato Cultivars to Root-knot Nematodes

HortScience ◽

10.21273/hortsci.35.4.569e ◽

2000 ◽

Vol 35 (4) ◽

pp. 569E-569d

Author(s):

J.C. Cervantes ◽

D.L. Davis ◽

G.C. Yencho

Keyword(s):

Ipomoea Batatas ◽

Nematode Species ◽

Nematode Resistance ◽

Root Knot Nematode ◽

Resistance Response ◽

Root Knot Nematodes ◽

Nematode Eggs ◽

Resistance Reaction ◽

Gall Index ◽

Race 2

This study was conducted to determine whether the type of pot used for the evaluation affected the resistance response of the sweetpotato plants, and to assess the resistance response to different root-knot nematode species. Five sweetpotato [Ipomoea batatas (L.) Lam] cultivars, `Beauregard', `Exce'l, `Jewel', `Hernandez', and `Porto Rico', were screened for M. incognita (race 3), Meloidogyne arenaria (race 2), and M. javanica, in both 10-cm-side, square pots and 4-cm-diameter, cone pots. Gall index, necrosis index, and number of nematode eggs per gram of root were used to estimate nematode-resistance reaction. Mean of all indices between the 2 pot types were not significantly different (α = 0.05). Gall and necrosis indices were not correlated in any of the cultivars. Resistance response depended on cultivars and nematode species for all variables analyzed. `Beauregard' was the most susceptible to Meloidogyne. `Hernandez' and `Excel' were found to be the most resistant cultivars to the Meloidogyne species.

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CHARACTERIZATION OF RESISTANCE TO ROOT-KNOT NEMATODES IN SWEETPOTATO

HortScience ◽

10.21273/hortsci.40.3.868e ◽

2005 ◽

Vol 40 (3) ◽

pp. 868e-869

Author(s):

J.A. Thies

Keyword(s):

Meloidogyne Incognita ◽

Ipomoea Batatas ◽

Nematode Species ◽

Plant Introduction ◽

Root Knot Nematode ◽

Race 1 ◽

Race 2 ◽

The U.S ◽

Greenhouse Tests

Thirteen sweetpotato (Ipomoea batatas) genotypes were characterized for resistance to Meloidogyne incognita, M. javanica, M. hapla, and M. arenaria races 1 and 2 in greenhouse tests. The following sweetpotato genotypes representing a range of reactions to M. incognita were evaluated: U.S. Plant Introduction (PI) 399163 (highly resistant = HR), Sumor (HR), Nemagold (HR), Excel (HR), Tinian (HR), Hernandez (resistant = R), Jewel (R), Regal (R), Porto Rico (intermediate = I), Centennial (susceptible = S), Georgia Jet (S), Sulfur (S), and Beauregard (S). Meloidogyne incognita was most pathogenic to sweetpotato of the four Meloidogyne spp. evaluated in these studies. The U.S. Plant Introduction (PI) 399163 and Sumor were resistant to M. incognita in all tests. Only two genotypes, Beauregard and Porto Rico, were susceptible to M. javanica. All genotypes evaluated were resistant to M. hapla, M. arenaria race 1, and M. arenaria race 2. Sumor, U.S. PI 399163, and Nemagold appear to provide the highest levels of resistance against the four Meloidogyne spp. used in these studies. Since M. incognita is the most commonly occurring root-knot nematode species in sweetpotato growing areas of the southern U.S. and is pathogenic to most of the commonly grown sweetpotato cultivars, efforts to develop resistant cultivars that have desirable horticultural characteristics for the U.S. market should be directed toward this root-knot nematode species.

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(362) Assessment of Woody Ornamental Plants for Resistance to Three Meloidogyne Species

HortScience ◽

10.21273/hortsci.40.4.1025a ◽

2005 ◽

Vol 40 (4) ◽

pp. 1025A-1025

Author(s):

Jyotsna Sharma ◽

Jim Rich

Keyword(s):

Ornamental Plants ◽

Nematode Species ◽

Leaf Margin ◽

Infested Soil ◽

Native Plant ◽

Root Knot Nematode ◽

Aesthetic Value ◽

Ligustrum Japonicum ◽

Nematode Eggs ◽

Native Shrubs

Plants infected with Meloidogyne spp. (root-knot nematodes) often are stunted and lose aesthetic value due to chlorosis, wilting, and leaf margin necrosis. We assessed reproduction of three root-knot nematode species, Meloidogyne arenaria, M. incognita, and M. javanica, on five plant taxa native to the southeastern U.S. The plant taxa included were: Hydrangea quercifolia `Oakleaf', Viburnum obovatum `Densa', Itea virginica `Little Henry', Illicium parviflorum, and Clethra alnifolia `Ruby Spice'. Three commonly grown non-native shrubs, Ligustrum japonicum `Texanum', Ilexcrenata `Compacta', and Buxus microphylla `Wintergem', also were included in the study to serve as susceptible, positive controls. Highest gall rating (10) was observed on roots of I. crenata `Compacta' infected with M. incognita, but highest number of eggs (6397 eggs/g of roots) was observed in plants of this cultivar inoculated with M. javanica. Few or no galls were observed on roots of the five native plant taxa, and nematode eggs were recovered only from roots of I. virginica `Little Henry' inoculated with M. arenaria and M. javanica (13 and 20 eggs/g of roots, respectively). Fresh weights of shoots or roots were not affected by nematode inoculation. Due to lack of root gall development and little or no reproduction on the native taxa, we conclude that these are resistant or immune to the three species of Meloidogyne and might be suitable for planting in infested soil.

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Host Reactions of Sweetpotato Genotypes to Root-knot Nematodes and Variation in Virulence of Meloidogyne incognita Populations

HortScience ◽

10.21273/hortsci.37.7.1112 ◽

2002 ◽

Vol 37 (7) ◽

pp. 1112-1116 ◽

Cited By ~ 18

Author(s):

J.C. Cervantes-Flores ◽

G.C. Yencho ◽

E.L. Davis

Keyword(s):

North Carolina ◽

Ipomoea Batatas ◽

Nematode Species ◽

Host Race ◽

Root Knot Nematode ◽

Root Knot Nematodes ◽

Differential Reaction ◽

Geographical Regions ◽

Host Status ◽

Soil Mix

Sweetpotato [Ipomoea batatas (L.) Lam.] genotypes were evaluated for resistance to North Carolina root-knot nematode populations: Meloidogyne arenaria (Neal) Chitwood races 1 and 2; M. incognita (Kofoid & White) Chitwood races 1, 2, 3, and 4; and M. javanica (Treub) Chitwood. Resistance screening was conducted using 150-cm3 Conetainers containing 3 sand: 1 soil mix. Nematode infection and reproduction were assessed as the number of egg masses produced by root-knot nematodes per root system. Host suitability for the root-knot nematode populations differed among the 27 sweetpotato genotypes studied. Five genotypes (`Beauregard', L86-33, PDM P6, `Porto Rico', and `Pelican Processor') were selected for further study based on their differential reaction to the different root-knot nematodes tested. Two African landraces (`Tanzania' and `Wagabolige') were also selected because they were resistant to all the nematode species tested. The host status was tested against the four original M. incognita races, and an additional eight populations belonging to four host races, but collected from different geographical regions. The virulence of root-knot nematode populations of the same host race varied among and within sweetpotato genotypes. `Beauregard', L86-33, and PDM P6 were hosts for all 12 M. incognita populations, but differences in the aggressiveness of the isolates were observed. `Porto Rico' and `Pelican Processor' had different reactions to the M. incognita populations, regardless of the host race. Several clones showed resistance to all M. incognita populations tested. These responses suggest that different genes could be involved in the resistance of sweetpotato to root-knot nematodes. The results also suggest that testing Meloidogyne populations against several different sweetpotato hosts may be useful in determining the pathotypes affecting sweetpotato.

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Greenhouse and field resistance in cucumber to root-knot nematodes

Nematology ◽

10.1163/156854199508270 ◽

1999 ◽

Vol 1 (3) ◽

pp. 279-284 ◽

Cited By ~ 5

Author(s):

S. Alan Walters ◽

Todd C. Wehner ◽

Kenneth R. Barker

Keyword(s):

Cucumis Sativus ◽

Multiple Root ◽

Nematode Species ◽

Nematode Resistance ◽

Field Resistance ◽

Field Conditions ◽

Meloidogyne Arenaria ◽

Root Knot Nematode ◽

Root Knot Nematodes ◽

Race 2

Abstract Ten cultigens were evaluated for resistance to Meloidogyne arenaria races 1 and 2, and M. javanica under greenhouse and field conditions. Resistance to M. arenaria races 1 and 2, and M. javanica was verified in Cucumis sativus var. hardwickii line LJ 90430 and to M. arenaria race 2 in C. sativus var. sativus Southern Pickler and Mincu in a greenhouse test. Another cultigen of C. sativus var. hardwickii (PI 215589) was found to be resistant to M. arenaria race 2 but not to other root-knot nematode species tested. LJ 90430 is the cultigen of choice to develop root-knot nematode resistant cucumbers, since it has multiple root-knot nematode resistance and is cross-compatible with cucumber. Greenhouse and field data were positively correlated (r = 0.74) over both years. Experiment repeatabilities were calculated from the cultigens infected with root-knot nematodes under both greenhouse and field conditions. Four environments (greenhouse and field over 2 years) were used in the analysis. Repeatabilities were high in all instances (ranging from 0.83-0.99) and indicated that the environment (field or greenhouse) was not an important factor in assessing root-knot nematode resistance for the cultigens evaluated. Resistenz von Gurkengegen Wurzelgallennematoden im Gewachshaus undim Freiland - Unter Gewachshausund Freilandbedingungen wurden zehn Cultigene auf ihre Resistenz gegen Meloidogyne arenaria Rassen 1 und 2 und gegen M. javanica gepruft. Bei Cucumis sativus var. hardwickii Linie LJ 90430 wurde im Gewachshausversuch Resistenz gegen M. arenaria Rassen 1 und 2 sowie gegen M. javanica nachgewiesen, und in C. sativus var. sativus "Southern Pickler" und "Mincu" Resistenz gegen M. arenaria Rasse 2. Cultigen C. sativus var. hardwickii (PI 215589) war resistent gegen M. arenaria Rasse 2 aber nicht gegen die anderen gepruften Arten von Wurzelgallennematoden. LJ 90430 ist das Cultigen der Wahl bei der Entwicklung von Gurken, die gegen Wurzelgallennematoden resistent sind, da es multiple Resistenzen gegen Wurzelgallennematoden besitzt und kreuzungsvertraglich mit Gurke ist. Die Ergebnisse der Gewachshaus- und Feldversuche waren uber beide Versuchsjahre hin positiv korreliert (r = 0,74). Ausgehend von den Cultigenen, die im Gewachshaus und im Freiland mit Wurzelgallennematoden infiziert waren, wurden die Wiederholbarkeiten der Versuche berechnet. Dabei wurden vier verschiedene Umweltbedingungen (Gewachshaus und Freiland uber zwei Jahre) verwendet. Die Wiederholbarkeiten waren in allen Fallen hoch (0,83-0,99) und zeigten an, dass die Umwelt (Freiland oder Gewachshaus) kein wichtiger Faktor bei der Bestimmung der Resistenz gegen Wurzelgallennematoden bei den gepruften Cultigenen war.

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Biostimulants for Plant Growth Promotion and Sustainable Management of Phytoparasitic Nematodes in Vegetable Crops

Agronomy ◽

10.3390/agronomy9100616 ◽

2019 ◽

Vol 9 (10) ◽

pp. 616 ◽

Cited By ~ 7

Author(s):

D’Addabbo ◽

Laquale ◽

Perniola ◽

Candido

Keyword(s):

Growth Promotion ◽

Raw Materials ◽

Control Strategies ◽

Nematode Species ◽

Suppressive Effect ◽

Vegetable Crops ◽

Root Knot Nematode ◽

Phytoparasitic Nematodes ◽

Nematode Eggs ◽

Almost All

The parasitism of root-knot nematodes, Meloidogyne spp., can cause heavy yield losses to vegetable crops. Plant biostimulants are often reported for a side-suppressive effect on these pests and many commercial products are increasingly included in sustainable nematode control strategies. Source materials of most biostimulants derived from plant or seaweed raw materials were documented for a reliable suppression of root-knot nematode species, whereas the suppressiveness of microbial biostimulants was found largely variable, as related to the crop and to environmental factors. Chitosan-based biostimulants were also stated for a variable phytonematode suppression, though clearly demonstrated only by a few number of studies. In a preliminary experimental case study, four commercial biostimulants based on quillay extract (QE), sesame oil (SO), seaweeds (SE), or neem seed cake (NC) were comparatively investigated for their effects against the root-knot nematode M. incognita on potted tomato. Soil treatments with all the four biostimulants resulted in a significant reduction of nematode eggs and galls on tomato roots, though NC and SO were significantly more suppressive than QE or SE. In addition, almost all biostimulant treatments also resulted in a significant improvement of tomato growth compared to the non-treated control. These preliminary results seem to confirm the literature data and clearly indicate the potential role of biostimulants for a safe nematode management both in organic and integrated crop systems.

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Screening Sweetpotato Genotypes for Resistance to a North Carolina Isolate of Meloidogyne enterolobii

Plant Disease ◽

10.1094/pdis-02-20-0389-re ◽

2020 ◽

Author(s):

Tanner Schwarz ◽

Eric Davis ◽

G. Craig Yencho ◽

Kenneth Pecota ◽

Chunying Li ◽

...

Keyword(s):

North Carolina ◽

Ipomoea Batatas ◽

Post Inoculation ◽

State University ◽

Root Knot Nematode ◽

Soil Mixture ◽

Initial Inoculum ◽

Meloidogyne Enterolobii ◽

Nematode Eggs ◽

Reproduction Factor

Potential resistance to the guava root-knot nematode, Meloidogyne enterolobii, in ninety-one selected sweetpotato [Ipomoea batatas (L.) Lam.] genotypes was evaluated in six greenhouse experiments. Ten thousand eggs of M. enterolobii were inoculated on each sweetpotato genotype grown in a 3:1 sand to soil mixture. Sixty days post inoculation, percent of total roots with nematode-induced galls was determined, and nematode eggs were extracted from roots. Significant differences (P ˂ 0.001) among sweetpotato genotypes were found in all six tests for gall rating, total eggs, and eggs per gram of root. Resistant sweetpotato genotypes were determined by final eggs per root system divided by the initial inoculum where Pf/Pi < 1 (reproduction factor; final egg count divided by initial inoculum of 10,000 eggs), and statistical mean separations were confirmed by Fisher’s LSD t test. Our results indicated that 19 out of 91 tested sweetpotato genotypes were resistant to M. enterolobii. Some of the susceptible genotypes included ‘Covington’, ‘Beauregard’, ‘NCDM04-001’, and ‘Hernandez’. Some of the resistant sweetpotato genotypes included ‘Tanzania’, ‘Murasaki-29’, ‘Bwanjule’, ‘Dimbuka-Bukulula’, ‘Jewel’, and ‘Centennial’. Most of the 19 resistant sweetpotato genotypes supported almost no M. enterolobii reproduction with less than 20 eggs/g root of M. enterolobii. A number of segregants from a ‘Tanzania’ x ‘Beauregard’ cross demonstrated strong resistance to M. enterolobii observed in the ‘Tanzania’ parent. In collaboration with NC State University sweetpotato breeding program, several of the genotypes evaluated in these tests are now being used to incorporate the observed resistance to M. enterolobii into commercial sweetpotato cultivars.

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Variation in Root Architecture Attributes at the Onset of Storage Root Formation among Resistant and Susceptible Sweetpotato Cultivars Infected with Meloidogyne incognita

HortScience ◽

10.21273/hortsci10746-18 ◽

2018 ◽

Vol 53 (12) ◽

pp. 1924-1929

Author(s):

Arthur Villordon ◽

Christopher Clark

Keyword(s):

Meloidogyne Incognita ◽

Ipomoea Batatas ◽

Root Formation ◽

Lateral Roots ◽

Root System Architecture ◽

Nematode Infection ◽

Storage Root ◽

Root Knot Nematode ◽

Inoculum Level ◽

Area And Volume

In sweetpotato (Ipomoea batatas), the successful emergence and development of lateral roots (LRs), the main determinant of root system architecture (RSA), determines the competency of adventitious roots (ARs) to undergo storage root formation. The present study investigated the effect of three levels of root-knot nematode (RKN) inoculum of race 3 of Meloidogyne incognita on LR length, number, area, and volume in ‘Beauregard’, ‘Evangeline’, and ‘Bayou Belle’, sweetpotato cultivars which are highly susceptible, moderately resistant, and highly resistant, respectively, to M. incognita. The three RKN levels were control (untreated), medium (500 eggs/pot), and high (5000 eggs/pot). In general, the number of galls after 20 days for each cultivar was consistent across RKN levels and two planting dates (PDs). ‘Beauregard’ inoculated with medium and high RKN levels showed 2.9 and 18.9 galls on each AR, respectively. ‘Evangeline’ had 0.5 and 3.4 galls at medium and high RKN levels, respectively. By contrast, ‘Bayou Belle’ showed only 0.9 galls at the high inoculum level. There was a significant PD × cultivar effect and cultivar × RKN level effect for all root attributes. LR attributes varied within and among resistant and susceptible cultivars with a general trend for increase in all root growth attributes in response to RKN infection in the first (PD1) and second PD (PD2). ‘Evangeline’ showed relatively consistent within-cultivar increase across PD1 (medium and high RKN levels) and PD2 (medium RKN level only). LR length, number, area, and volume within ‘Evangeline’ plants subjected to high RKN increased 122%, 126%, 154%, and 136%, respectively, relative to the untreated control plants in PD1. ‘Evangeline’ (PD1 and PD2) and ‘Bayou Belle’ (PD1 only) showed significant increase in all root attributes relative to the susceptible ‘Beauregard’ at medium or high RKN levels. In PD1, LR length, number, area, and volume in ‘Evangeline’ plants subjected to high RKN increased 165%, 167%, 176%, and 190%, respectively, relative to ‘Beauregard’ plants at the same RKN level. These findings are consistent with some data in other systems wherein nematode infection is associated with cultivar-specific root compensatory growth and demonstrate how genotype and environment interact to modify root development responses. These data can be used to further understand the role of cultivar-specific responses to nematode infection and can lead to the consideration of root traits in selection strategies.

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Host suitability of vetiver grass to Meloidogyne incognita and M. javanica

Nematology ◽

10.1163/156854107779969736 ◽

2007 ◽

Vol 9 (1) ◽

pp. 49-52 ◽

Cited By ~ 3

Author(s):

Hendrika Fourie ◽

Caroline Leswifi ◽

Alex H. McDonald ◽

Dirk De Waele

Keyword(s):

Production Systems ◽

Nematode Species ◽

Host Suitability ◽

Egg Laying ◽

Vetiver Grass ◽

Root Knot Nematode ◽

Green Pepper ◽

Nematode Reproduction ◽

Rf Values ◽

Race 2

Abstract Root-knot nematodes (Meloidogyne spp.) are economically important pathogens of many agricultural crops, and the frequency of occurrence, abundance and importance of these nematodes in resource-poor agricultural production systems make control necessary. The host suitability of vetiver grass to Meloidogyne javanica and M. incognita race 2 was investigated and compared with the host status of the six crops included in the North Carolina Differential Host Range Test, i.e., tomato (cv. Rutgers), groundnut (cv. Florunner), watermelon (cv. Charleston Gray), green pepper (cv. California Wonder), cotton (cv. Deltapine) and tobacco (line NC 95). Each plant was inoculated with 10 000±500 eggs and second-stage juveniles (J2) of either M. javanica or M. incognita race 2, 3 weeks after emergence. Nematode reproduction assessments were done 56 days after inoculation. Significant differences in egg-laying female (ELF) indices, number of egg-masses and eggs and J2 per root system and reproduction factor (RF) values were recorded among the crops for both nematode species. Vetiver grass exhibited RF-values lower than 1 for both M. javanica and M. incognita race 2, indicating resistance to these root-knot nematode species.

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Effect of natural disinfectant (Moringa oleifera) and a chemical disinfectant (calcium hypochlorite) on nematode eggs: bioefficiency and impact of physico-chemical variables

Journal of Water Sanitation and Hygiene for Development ◽

10.2166/washdev.2020.001 ◽

2020 ◽

Vol 10 (2) ◽

pp. 335-346

Author(s):

Arnold Landry Fotseu Kouam ◽

Gideon Aghaindum Ajeagah

Keyword(s):

Petri Dish ◽

Nematode Species ◽

Optical Microscope ◽

Chemical Parameters ◽

Calcium Hypochlorite ◽

Physico Chemical ◽

Before And After ◽

Nematode Eggs ◽

Chemical Disinfectant ◽

Physical And Chemical

Abstract The aim of this study is to determine the effectiveness of disinfectant on the viability of eggs from three nematode species (Ascaris, Trichuris, Ankylostoma). It was conducted in a microcosm from June 2018 to June 2019. The wastewater scan was sampled using 5 L sterile containers, the sample was arranged in four replicas, three tests and one control. The test samples received three disinfectants (Moringa, calcium hypochlorite and Moringa associated with calcium hypochlorite) at varying concentrations. The physical and chemical parameters were measured before and after the application of each disinfectant. The samples were then observed under an optical microscope. The viability of the eggs was determined by incubating the Petri dish samples at 30 °C for 30 days. The analyses show that some physicochemical parameters can significantly influence the efficacy of disinfectant on the eggs. The calcium hypochlorite associated with Moringa at 0.6 g/L showed greater efficacy on reducing viability and inactivation of eggs with 100% efficacy yield rates on Ankylostoma and Trichuris trichiuria and 97% on Ascaris lumbricoides eggs; this efficacy is significantly different from that observed on samples treated with Moringa and simple calcium hypochlorite. Of the three parasites tested, A. lumbricoides showed greater resistance to the disinfectant.

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