Reproduction of Meloidogyne arenaria race 2 on flue-cured tobacco with putative resistance derived from Nicotiana repanda

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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Characterization of Resistance Conferred by the N gene to Meloidogyne arenaria Races 1 and 2, M. hapla, and M. javanica in Two Sets of Isogenic Lines of Capsicum annuum L.

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.125.1.71 ◽

2000 ◽

Vol 125 (1) ◽

pp. 71-75 ◽

Cited By ~ 26

Author(s):

Judy A. Thies ◽

Richard L. Fery

Keyword(s):

Capsicum Annuum ◽

Nematode Resistance ◽

N Gene ◽

Recurrent Parent ◽

Resistance Locus ◽

Meloidogyne Arenaria ◽

Meloidogyne Hapla ◽

Root Knot Nematode ◽

Race 1 ◽

Race 2

Two isogenic sets of bell pepper (Capsicum annuum L.) lines (differing at the N root-knot nematode resistance locus) were characterized for resistance to Meloidogyne arenaria (Neal) Chitwood races 1 and 2, M. hapla Chitwood, and M. javanica (Treub) Chitwood in greenhouse and growth chamber tests. The isogenic sets of C. annuum were `Charleston Belle' (NN) and `Keystone Resistant Giant' (nn-recurrent parent), and `Carolina Wonder' (NN) and `Yolo Wonder B' (nn-recurrent parent). Meloidogyne arenaria race 1 is pathogenic to C. annuum. `Charleston Belle' and `Carolina Wonder' exhibited high resistance to M. arenaria race 1. Their respective recurrent backcross parents, `Keystone Resistant Giant' and `Yolo Wonder B', were susceptible to M. arenaria. Meloidogyne arenaria race 2 and M. javanica are not highly pathogenic to pepper. However, `Charleston Belle' and `Carolina Wonder' both exhibited higher (P≤0.05) resistance to M. arenaria race 2 and M. javanica than `Keystone Resistant Giant' and `Yolo Wonder B'. Meloidogyne hapla is pathogenic to pepper. Both `Charleston Belle' and `Carolina Wonder' and their respective recurrent parents, `Keystone Resistant Giant' and `Yolo Wonder B', were susceptible to M. hapla. We concluded that the N gene confers resistance to M. arenaria races 1 and 2, and M. javanica in C. annuum, but the N gene does not condition resistance to M. hapla.

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Soil temperature and egg mass formation by Meloidogyne arenaria on oriental melon (Cucumis melo L.)

Nematology ◽

10.1163/156854103322746896 ◽

2003 ◽

Vol 5 (5) ◽

pp. 721-725 ◽

Cited By ~ 6

Author(s):

So Deuk Park ◽

Dong Geun Kim ◽

Il Kweon Yeon

Keyword(s):

Soil Temperature ◽

Threshold Temperature ◽

Egg Mass ◽

Data Sets ◽

Meloidogyne Arenaria ◽

Degree Days ◽

Oriental Melon ◽

Race 2 ◽

Cucumis Melo L ◽

Mass Formation

AbstractEgg masses of Meloidogyne arenaria race 2 were observed on the second planting of oriental melon by the time of its first harvest under glasshouse conditions in Korea. Time and degree-days above 5°C (DD5) for egg mass formation after April were about 24.5 days and 500 DD5. Higher mean soil temperature shortened the days required for egg mass formation. A threshold temperature for degree-days accumulation of 12.2°C was selected on the basis of lowest coefficient of variation among data sets of time to egg mass formation. We propose the use of DD12.2 for predicting the time to egg mass formation of M. arenaria under these glasshouse conditions.

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First Report of the Root-Knot Nematode Meloidogyne arenaria Race 2 from Several Vegetable Crops in Jordan

Plant Disease ◽

10.1094/pd-89-0206b ◽

2005 ◽

Vol 89 (2) ◽

pp. 206-206 ◽

Cited By ~ 3

Author(s):

M. Karajeh ◽

W. Abu-Gharbieh ◽

S. Masoud

Keyword(s):

North Carolina ◽

Meloidogyne Arenaria ◽

Vegetable Crops ◽

Root Knot Nematode ◽

Lateral Field ◽

Differential Host ◽

First Report ◽

Race 1 ◽

Meloidogyne Spp ◽

Race 2

Meloidogyne arenaria (Neal) Chitwood (race 2) is reported for the first time in Jordan. The nematode populations were recovered from several vegetable crops, including tomato (Lycopersicon esulentum Mill), squash (Cucurbita pepo L.), cucumber (Cucumis sativus L.), and bean (Phaseolus vulgaris L.), at Dier Alla in the northern area of the Jordan Valley. Symptoms included root galling, leaf chlorosis, and stunting. Galled plant root samples were collected during a survey conducted from May 2002 to August 2003 covering most of the irrigated agricultural areas of Jordan. Eighty-three Meloidogyne spp. populations were collected from various vegetable crops and fruit trees. Identification to species and race levels of the nematode populations was based on combination of currently available methods including nematode morphology, host preference based on the North Carolina (NC) differential host test (1), and cytogenetics and DNA-fingerprinting. Seventy of the eighty-three collected populations were identified as M. javanica, five as M. incognita (race 1), three as M. incognita (race 2), and five as M. arenaria (race 2). The perineal patterns of M. arenaria were characterized by a low, round to indented dorsal arch near the lateral field with irregular forks in the lateral field, fine smooth striae, and a distinct whorl. Race 2 was identified with the NC differential host test. Cytogenetic studies indicated that M. arenaria populations were triploid with an average of 52.2 chromosomes, while the populations of M. incognita (race 1), M. incognita (race 2), and M. javanica were hypotriploid with an average of 45.2, 46.1, and 46.7 chromosomes, respectively. Two polymerase chain reaction (PCR)-based assays were used to confirm species identification and to study genetic variability of the Meloidogyne spp. populations including sequence characterized amplified regions (SCAR) and random amplified polymorphic DNA (RAPD). In the SCAR-PCR-based assay (2), typical DNA products of 420, 670, or 1,200 bp in size were amplified by using extracted DNA of M. arenaria (race 2), M. javanica, or M. incognita (race 1 or 2), respectively, as template DNA. The RAPD-PCR primer, OPA-01, produced DNA patterns with bands that clearly distinguished M. arenaria from the other two Meloidogyne spp. To our knowledge, this is the first report of the root-knot nematode, M. arenaria race 2, in Jordan. References: (1) A. Taylor and J. Sasser, North Carolina State University Graphics, Raleigh, NC, 1978. (2) C. Zijlstra et al. Nematology 2:847, 2000.

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Reproduction of Meloidogyne arenaria race 2 on Flue-cured tobacco possessing resistance genes Rk1 and/or Rk2

Journal of Nematology ◽

10.21307/jofnem-2021-042 ◽

2021 ◽

Vol 53 ◽

pp. 1-13

Author(s):

Noah Adamo ◽

Charles S. Johnson ◽

T. David Reed ◽

Jonathan D. Eisenback

Keyword(s):

Resistance Genes ◽

Meloidogyne Arenaria ◽

Race 2

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Diversity of Meloidogyne arenaria using morphological, cytological and molecular approaches

Nematology ◽

10.1163/156854108786161526 ◽

2008 ◽

Vol 10 (6) ◽

pp. 819-834 ◽

Cited By ~ 23

Author(s):

Maria Ritta Almeida ◽

Regina Carneiro ◽

Marcilene dos Santos ◽

Myrian Tigano ◽

Ana Cristina Gomes ◽

...

Keyword(s):

Bootstrap Support ◽

Meloidogyne Arenaria ◽

Molecular Approaches ◽

Morphological Studies ◽

Race 1 ◽

Unidentified Species ◽

High Bootstrap ◽

Race 2 ◽

Species Specific ◽

High Level

AbstractThirteen Meloidogyne arenaria isolates representing two cytological types (3n = 51-56, 2n = 42-48) and four enzymatic phenotypes (esterase and malate dehydrogenase: A3N1, A2N1, A1N1, A2N3) were studied using different approaches. The analysis of molecular markers showed a high level of polymorphism among the isolates. The trees obtained with RAPD or ISSR polymorphisms showed concordant results and agree with morphological studies. By considering morphometrical and morphological features, it was possible to conclude that the isolate with enzymatic phenotype A2N3 race 1 was the M. arenaria described in 1949 by Chitwood and appearing clearly separated in the trees, as well as in the outgroups. The seven isolates with phenotype A2N1 from different localities and isolate A1N1 can be considered morphometrically typical of M. arenaria race 2 and they were apparently clustered by geographical origin. Morphologically, they differed from isolate A2N3 race 1. The two isolates with phenotype A3N1 appeared to be closely related to the isolate of M. morocciensis and, considering all of the features described for this species, were identified as such. The two isolates A2N3 race 2 were identified either as an atypical M. arenaria or an unidentified species (females and males having atypical stylets), and clustered together and separated from other M. arenaria isolates with high bootstrap support. The same M. arenaria isolates were tested with the species-specific molecular marker, type SCAR. A fragment of 420 bp was obtained for ten isolates of M. arenaria, including the atypical A2N3 race 2 and M. morocciensis. This fragment was not amplified for three typical A2N1 isolates of M. arenaria.

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Pathogenicity and Host–Parasite Relationships of Meloidogyne arenaria in Sweet Basil

Plant Disease ◽

10.1094/pdis-92-9-1329 ◽

2008 ◽

Vol 92 (9) ◽

pp. 1329-1335 ◽

Cited By ~ 3

Author(s):

N. Vovlas ◽

A. Troccoli ◽

A. Minuto ◽

C. Bruzzone ◽

N. Sasanelli ◽

...

Keyword(s):

Population Density ◽

Plant Height ◽

Initial Population ◽

Meloidogyne Arenaria ◽

Fresh Weight ◽

Nematode Reproduction ◽

Initial Population Density ◽

Sweet Basil ◽

Vascular Elements ◽

Race 2

Stunted growth of sweet basil (cv. Genovese) associated with large patches and severe soil infestations by the root-knot nematode Meloidogyne arenaria race 2 were observed in open fields at the end of the crop-growing season in Albenga, province of Savona, Northern Italy by early September 2007. Observed morphological traits of nematode life stages and results of analysis of isozyme electrophoretic patterns and differential host tests were used for nematode species and race identification. Nematode-induced mature galls (either in naturally infected plants or in artificially inoculated root tissues) were spherical or ellipsoidal and confluent along the root axis, containing usually several females, males, and egg-masses with eggs. Feeding sites were characterized by the development of giant cells that contained several hypertrophied nuclei and nucleoli. Giant cell cytoplasm was aggregated along the thickened cell walls. Vascular elements within galls appeared disorganized and disrupted. Due to the heavy damage observed, the relationships between the initial population density and growth of basil plants was also tested in a greenhouse experiment in which inoculum levels varied from 0 to 512 eggs and juveniles/cm3 of soil. Height and top fresh weight data of the inoculated and control plants was fitted to Seinhorst's model. Tolerance limits with respect to plant height and fresh top weight of basil cv. Genovese plants to M. arenaria race 2 were estimated as 0.15 eggs and juveniles/cm3 of soil. The minimum relative values (m) for plant height and top fresh weight were 0.39 and 0.19 at initial nematode population density (Pi) ≥16 eggs and juveniles/cm3 of soil, respectively. The maximum nematode reproduction rate (Pf/Pi) was 448.7 times at an initial population density of 4 eggs and second-stage juveniles/cm3 of soil.

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Campus Diversity: Implementing the Town Hall Approach for Racial and Cultural Understanding at a Predominantly White University

NASPA Journal ◽

10.2202/0027-6014.1191 ◽

2002 ◽

Vol 40 (1) ◽

Author(s):

Celina Valentina Echols ◽

Young Suk Hwang ◽

Connie Nobles

Keyword(s):

Predominantly White ◽

Campus Climate ◽

Cross Cultural ◽

Town Hall ◽

Campus Diversity ◽

Predominantly White University ◽

Attitudes And Knowledge ◽

Race 2 ◽

The Town ◽

Cultural Interactions

This paper uses students responses from the dialogues of a town hall meeting to examine the beliefs, attitudes, and knowledge about racial and cultural diversity at a mid-size, predominantly white university in Louisiana. The four major themes that emerged from this experience were: (1) perceptions about race, (2) stereotypical beliefs about cross-cultural interactions, (3) uncomfortable campus climate, and (4) disequilibria associated with prejudicial teaching by parents. Implications and recommendations for increasing positive cross-cultural interactions among members of the campus community are discussed.

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DISTRIBUTION AND RACE COMPOSITION OF DOWNY MILDEW (Plasmopara halstedii (Farl.) Berl. and de Toni) IN BULGARIA / EXTENSION Y RAZAS DEL MILDIU (Plasmopara halstedii (Farl.) Berl. y de Toni) EN BULGARIA / ÉTENDUE ET RACES DE LA ROUILLE (Plasmopara halstedii (Farl.) Berl. and de Toni) EN BULGARIE

Helia ◽

10.1515/helia.2000.23.33.25 ◽

2000 ◽

Vol 23 (33) ◽

pp. 25-32

Author(s):

P.S. Shindrova

Keyword(s):

Downy Mildew ◽

Resistance Gene ◽

The Other ◽

Plasmopara Halstedii ◽

North West ◽

North East ◽

Race 1 ◽

Race 2 ◽

Production Areas ◽

Number Of Authors

SUMMARY Downy mildew caused by the fungus Plasmopara halstedii is the main disease on sunflower in Bulgaria. In recent years a number of authors have reported the occurrence of new more virulent races of the pathogen. According to other authors these races demonstrate resistance to the fungicides used up to now. This fact is rather alarming and imposes the necessity of annual researches with the aim of following the changes in the downy mildew race variability. In the period 1995-1997 downy mildew isolates were collected from the following locations: Bourgas, Boyanovo, Karnobat, Ognyanovo, Selanovtsi, Kroushari, Lovech, Koubrat, Brashlyan, Sitovo, Tervel, Targovishte, IWS “Dobroudja” and Dobrich. The samples were assessed for virulence on a set of sunflower differential - lines under greenhouse conditions. The obtained results do not reveal a great race variability of downy mildew population in Bulgaria. In the period of study two races of the pathogen were identified: race 1 which infects the differential lines without genes for resistance to the pathogen. It is distributed in all sunflower production areas of the country. The other one is race 2. It is of limited distribution and has been registered in individual fields of north-east and north-west Bulgaria. It attacks the differential lines carrying the resistance gene Pl-1.

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Reactions of lines of Phaseolus atropurpureus to four species of root-knot nematode

Australian Journal of Agricultural Research ◽

10.1071/ar9720623 ◽

1972 ◽

Vol 23 (4) ◽

pp. 623

Author(s):

EM Hutton ◽

WT Williams ◽

LB Beall

Keyword(s):

Lycopersicon Esculentum ◽

Differential Resistance ◽

Meloidogyne Arenaria ◽

Root Knot Nematode ◽

Root Knot Nematodes ◽

Increased Susceptibility

In each of two years the reactions of 36 lines of Phaseolus atropurpureus to the four root-knot nematodes Meloidogyne arenaria, M. hapla, M. incognita, and M. javanica were studied. Seven of the experimental lines were common to the two years. Two known susceptible species, Phaseolus lathyroides and Lycopersicon esculentum (tomato cv. Grosse Lisse), were used as controls. Four macroscopic and four microscopic reactions were recorded on each occasion, and the results analysed. Resistance to the four nematodes was present in all lines of P. atropurpureus. There was also evidence of differential resistance between lines; some showed increased resistance to all nematodes except M. hapla, and others showed both increased susceptibility to M. hapla and increased resistance to M. javanica. The severity of attack on thc controls was significantly less in the second ycar. Several explanations for this are advanced.

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