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

HortScience ◽  
2002 ◽  
Vol 37 (7) ◽  
pp. 1112-1116 ◽  
Author(s):  
J.C. Cervantes-Flores ◽  
G.C. Yencho ◽  
E.L. Davis

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.

HortScience ◽  
2004 ◽  
Vol 39 (1) ◽  
pp. 120-123 ◽  
Author(s):  
Martin Schochow ◽  
Steven A. Tjosvold ◽  
Antoon T. Ploeg

Lisianthus [Eustoma grandiflorum (Raf.) Shinn.] plants were grown in soil infested with increasing densities of Meloidogyne hapla Chitwood, M. incognita (Kofoid & White) Chitwood, or M. javanica (Treub) Chitwood, root-knot nematodes. Compared to tomato plants grown in soil with the same nematode numbers and species, lisianthus had less severe root symptoms, suffered less damage, and resulted in lower nematode multiplication rates. Lisianthus was a better host for M. javanica than for M. incognita, and a poor host for M. hapla. Lisianthus shoot weights were significantly reduced after inoculation with M. javanica or M. hapla, but not after M. incognita inoculation. The number of flowers produced per lisianthus plant was reduced by all three nematode species. The results show that the root-knot nematode species that are most common in California may cause significant damage in the cut-flower production of lisianthus.


HortScience ◽  
2000 ◽  
Vol 35 (4) ◽  
pp. 569E-569d
Author(s):  
J.C. Cervantes ◽  
D.L. Davis ◽  
G.C. Yencho

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.


2005 ◽  
Vol 95 (2) ◽  
pp. 158-165 ◽  
Author(s):  
A. Pegard ◽  
G. Brizzard ◽  
A. Fazari ◽  
O. Soucaze ◽  
P. Abad ◽  
...  

In the pepper Capsicum annuum CM334, which is used by breeders as a source of resistance to Phytophthora spp. and potyviruses, a resistance gene entirely suppresses reproduction of the root-knot nematode (Meloidogyne spp.). The current study compared the histological responses of this resistant line and a susceptible cultivar to infection with the three most damaging root-knot nematodes: M. arenaria, M. incognita, or M. javanica. Resistance of CM334 to root-knot nematodes was associated with unidentified factors that limited nematode penetration and with post-penetration biochemical responses, including the hypersensitive response, which apparently blocked nematode migration and thereby prevented juvenile development and reproduction. High-performance liquid chromatography analysis suggested that phenolic compounds, especially chlorogenic acid, may be involved in CM334 resistance. The response to infection in the resistant line varied with root-knot nematode species and was correlated with nematode behavior and pathogenicity in the susceptible cultivar: nematode species that quickly reached the vascular cylinder and initiated feeding sites in the susceptible cultivar were quickly recognized in CM334 and stopped in the epidermis or cortex. After comparing our data with those from other resistant pepper lines, we suggest that timing of the resistance response and the mechanism of resistance vary with plant genotype, resistance gene, and root-knot nematode species.


Nematology ◽  
2021 ◽  
pp. 1-9
Author(s):  
Hung X. Bui ◽  
Johan A. Desaeger

Summary Cover crops can be a useful tool for managing plant-parasitic nematodes provided they are poor or non-hosts for the target nematode species. A glasshouse experiment was done to determine the host status of four common cover crops in Florida, sunn hemp, cowpea, sorghum sudangrass and sunflower, to pure populations of four common tropical root-knot nematode (RKN) species Meloidogyne javanica (Mj), M. incognita (Mi), M. enterolobii (Me) and M. arenaria (Ma). Tomato was included as a susceptible control. Eight weeks after nematode inoculation (WAI), tomato showed the highest root gall damage for all tested RKN species, with gall indices (GI) between 7 (Ma) and 8.5 (Me) and reproduction factor (RF) ranging from 20 (Ma) to 50 (Mj). No visible root galls were observed for any of the RKN species on sunn hemp and sorghum sudangrass at 8 WAI. However, Mj and Mi were able to reproduce slightly on sorghum sudangrass (RF = 0.02 and 0.79, respectively). Sunflower and cowpea were infected by all four tested RKN species, but host suitability varied. Sunflower root galling ranged from 1.1 (Me) to 4.5 (Mj) and RF = 3.2 (Me) to 28.7 (Mj), while cowpea root galling ranged from 0.6 (Mi) to 5.1 (Me) and RF = 0.8 (Mi) to 67.3 (Mj). Sunn hemp and, to a lesser extent, sorghum sudangrass were poor hosts to all four tested RKN species. Sunflower was a good host to all RKN species, but root gall damage and RF were lowest for Me. Cowpea was a good host to Mj, Me and Ma, but a poor host to Mi. Our results confirm and stress the importance of RKN species identification when selecting cover crops as an RKN management strategy.


HortScience ◽  
2005 ◽  
Vol 40 (3) ◽  
pp. 868e-869
Author(s):  
J.A. Thies

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.


HortScience ◽  
2008 ◽  
Vol 43 (6) ◽  
pp. 1911-1914 ◽  
Author(s):  
G. Craig Yencho ◽  
Kenneth V. Pecota ◽  
Jonathan R. Schultheis ◽  
Zvezdana-Pesic VanEsbroeck ◽  
Gerald J. Holmes ◽  
...  

‘Covington’ is an orange-fleshed, smooth-skinned, rose-colored, table-stock sweetpotato [Ipomoea batatas (L.) Lam.] developed by North Carolina State University (NCSU). ‘Covington’, named after the late Henry M. Covington, an esteemed sweetpotato scientist at North Carolina State, was evaluated as NC98-608 in multiple state and regional yield trials during 2001 to 2006. ‘Covington’ produces yields equal to ‘Beauregard’, a dominant sweetpotato variety produced in the United States, but it is typically 5 to 10 days later in maturity. ‘Covington’ typically sizes its storage roots more evenly than ‘Beauregard’ resulting in fewer jumbo class roots and a higher percentage of number one roots. Total yields are similar for the two clones with the dry matter content of ‘Covington’ storage roots typically being 1 to 2 points higher than that of ‘Beauregard’. ‘Covington’ is resistant to fusarium wilt [Fusarium oxysporum Schlect. f.sp. batatas (Wollenw.) Snyd. & Hans.], southern root-knot nematode [Meloidogyne incognita (Kofoid & White 1919) Chitwood 1949 race 3], and moderately resistant to streptomyces soil rot [Streptomyces ipomoeae (Person & W.J. Martin) Wakswan & Henrici]. Symptoms of the russet crack strain of Sweet Potato Feathery Mottle Virus have not been observed in ‘Covington’. The flavor of the baked storage roots of ‘Covington’ has been rated as very good by standardized and informal taste panels and typically scores as well or better in this regard when compared with ‘Beauregard’.


2021 ◽  
Author(s):  
Radwa G. Mostafa ◽  
Aida M. El-Zawahry ◽  
Ashraf E. M. Khalil ◽  
Ameer E. Elfarash ◽  
Ali D. A. Allam

Abstract Background Plant-parasitic nematodes are extremely dangerous pests in a variety of economically important crops. The purpose of this study was a survey of all nematode species existing in banana from three sites in Assiut Governorate, Egypt and to characterize the most common species by morphological, morphometric and molecular techniques (PCR with species-specific primers). Then, study of resistance or sensitivity of some banana cultivars to root-knot nematodes.Methods and Results Four nematodes, Meloidogyne, Rotylenchulus reniformis, Helicotylenchus and Pratylenchus were isolated and identified from soil and root samples collected from banana plants. Most frequently occurring of plant parasitic nematode species in banana was Meloidogyne. Former research found differences in species and in resistance to root-knot nematodes among the examined plant cultivars. Identification of Root-knot nematodes by Characterize of morphometric, molecularly, morphological isolate of Meloidogyne related to banana plants. The results revealed that the identified nematode species, Meloidogyne javanica, is the most common plant-parasitic nematodes in all locations. Data on the susceptibility of the tested banana cultivars to M. javanica revealed that Grand Naine was highly susceptible (HS) however, Magraby was susceptible (S) but Williams and Hindi cultivars were moderately resistant (MR).Conclusions we concluded that a survey revealed the significant prevalence of Meloidogyne javanica, the most important nematodes on banana in Assiut. The morphometric, morphological, and molecular identification were harmonic with one another. In addition to the host response of certain banana cultivars, to M. javanica that resistance is of significance and can be helpful to incorporate through planning control measures for root- knot nematodes.


Plant Disease ◽  
2019 ◽  
Vol 103 (9) ◽  
pp. 2288-2294
Author(s):  
Shamsul A. Bhuiyan ◽  
Kylie Garlick ◽  
George Piperidis

Root-lesion nematode (Pratylenchus zeae) and root-knot nematode (Meloidogyne javanica) are two important pathogens of sugarcane (Saccharum hybrid). No commercial cultivars are resistant to these nematodes in Australia. Twenty accession lines of S. spontaneum, a wild relative of sugarcane, were tested against these two nematode species. S. spontaneum lines were tested twice for resistance to root-lesion nematode and three times for root-knot nematode. Reproduction (final population/starting population) of root-lesion nematodes was significantly lower in 17 of the 20 S. spontaneum accession lines tested in two experiments compared with two commercial cultivars. Four S. spontaneum lines supported a significantly lower number of root-lesion nematodes per gram of root than that of two commercial sugarcane cultivars. Reproduction of root-knot nematodes was significantly lower in 16 S. spontaneum lines compared with two commercial cultivars. Fourteen of the S. spontaneum lines tested supported significantly fewer eggs per gram of root compared with two commercial cultivars. This study showed that S. spontaneum lines possessed resistance for root-lesion and root-knot nematodes. Targeted crossing with commercial hybrid parental lines should be conducted to introduce nematode resistance into sugarcane cultivars for the Australian sugar industry.


Nematology ◽  
1999 ◽  
Vol 1 (3) ◽  
pp. 279-284 ◽  
Author(s):  
S. Alan Walters ◽  
Todd C. Wehner ◽  
Kenneth R. Barker

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.


Plant Disease ◽  
1997 ◽  
Vol 81 (11) ◽  
pp. 1333-1333 ◽  
Author(s):  
A. Zazzerini ◽  
L. Tosi ◽  
P. M. Vicente

Sunflower (Helianthus annuus L.) recently was reintroduced to Mozambique because of renewed interest in oil-seed production for domestic consumption. In April 1997, disease surveys were carried out in two fields in southern Mozambique (Maputo region). Several plants of Pan 735, a South African cultivar, showed yellowing of the leaves and stunting. These plants wilted during the day but recovered their turgidity at night. Diseased plants were easily pulled from the soil due to almost complete destruction of the root system. Numerous galls were found on affected roots, compared with healthy plants. Meloidogyne javanica (Treub) Chitwood and M. incognita (Kofoid & White) Chitwood were identified by M. Di Vito (personal communication) based on 20 female perineal patterns observed with a light microscope. M. incognita was more prevalent than M. javanica. Also observed were Alternaria helianthi (Hansf.) Tubaki & Nishihara and Sclerotium bataticola Taub. Root-knot nematodes (Meloidogyne spp.), common on sunflower, cause severe damage and reduce both seed yield and seed oil content (1). These two nematode species have also been observed on sunflower in other African countries (Zambia, South Africa, Egypt) but this is the first report of root-knot nematode on sunflower in Mozambique. Reference: (1) M. Di Vito et al. Nematol. Medit. 24:109, 1996.


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