scholarly journals Variations in the level of resistance to root-knot nematodes (Meloidogyne spp.) infestation among ten cowpeas (Vigna unguiculata L. Walp.) genotypes

2019 ◽  
Vol 54 (2) ◽  
pp. 68-78
Author(s):  
F. Kankam ◽  
E. N.K. Sowley ◽  
J. Adomako ◽  
A. Boateng
Keyword(s):  
Vigna Unguiculata ◽  
Root Knot Nematode ◽  
Root Knot Nematodes ◽  
Second Stage ◽  
Randomized Design ◽  
Significant Difference ◽  
Environmentally Safe ◽  
Meloidogyne Spp ◽  
The University ◽  
Moderately Resistant

The cultivation of cowpea (Vigna unguiculata L. Walp.) cultivars that are tolerant to root-knot nematode attack is among the environmentally safe approach to managing the root-knot nematode menace in cultivated crops. In this study, the tolerance of 10 cowpea genotypes to root-knot nematodes infestation was evaluated in a pot experiment conducted in a Screenhouse, at the University for Development Studies, Nyankpala Campus. The experiment was laid out in a completely randomized design with three replications. The number of second stage juveniles (J2) per 250 cm3 of soil sample were counted while the severity of root-knot nematode damage (root galls) was assessed. The reproduction index (RI) was used to classify the varieties as resistant or susceptible. There was a significant difference (P < 0.05) in the number of second stage juveniles of root-knot nematode (RKN), galling index and RI among the genotypes tested. The study revealed that cowpea genotypes SARI 1-4-90, Padi tuya, Songotra, IT99K-1122, Sanzi and Apagbaala were moderately resistant whereas cowpea genotypes IT86D-610, Zaayura, SARI 5-5-5 and IT07K-299-6 were slightly resistant. Thus, the six moderately resistant cowpea genotypes were suggested to be used as a source of resistance to RKN in future breeding works.

scholarly journals Root-knot Nematode Resistance in Cucumber and Horned Cucumber

HortScience ◽  
1993 ◽  
Vol 28 (2) ◽  
pp. 151-154 ◽  
Author(s):  
S. Alan Walters ◽  
Todd C. Wehner ◽  
Kenneth R. Barkel
Keyword(s):  
Cucumis Sativus ◽  
Nematode Resistance ◽  
Plant Introduction ◽  
Root Knot Nematode ◽  
Root Knot Nematodes ◽  
Breeding Lines ◽  
Meloidogyne Spp ◽  
Race 2 ◽  
Moderately Resistant

Cucumber (Cucumis sativus L.) and horned cucumber (C. metuliferus Naud.) germplasm were evaluated for their resistance to root-knot nematodes (Meloidogyne spp.). All 24 C. metuliferus cultigens evaluated were resistant to all root-knot nematodes tested-M. incognita (Kofoid and White) Chitwood race 3, M. arenaria (Neal) Chitwood race 2, and M. hapla Chitwood. All 884 C. sativus cultigens (cultivars, breeding lines, and plant introduction accessions) tested were resistant to M. hapla and few to M. incognita race 3. Only 50 of 884 C. sativus cultigens evaluated were somewhat resistant to M. arenaria race 2 and M. incognita race 3. A retest of the most resistant C. sativus cultigens revealed that LJ 90430 [an accession of C. sativus var. hardwickii (R.) Alef.] and `Mincu' were the only cultigens that were moderately resistant to M. arenaria race 2. LJ 90430 was the only cultigen, besides the two retested C. metuliferus cultigens, that was resistant to M. javanica (Treub) Chitwood. All C. sativus cultigens retested, including LJ 90430, were highly susceptible to M. incognita races 1 and 3. The two C. metuliferus cultigens retested were highly resistant to all root-knot nematodes tested-M. arenaria race 2, M. incognita races 1 and 3, and M. javanica.

Genetic diversity of Meloidogyne spp. parasitising potato in Brazil and aggressiveness of M. javanica populations on susceptible cultivars

Nematology ◽  
2017 ◽  
Vol 19 (1) ◽  
pp. 69-80 ◽  
Author(s):  
Israel L. Medina ◽  
Cesar B. Gomes ◽  
Valdir R. Correa ◽  
Vanessa S. Mattos ◽  
Philippe Castagnone-Sereno ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Rapd Markers ◽  
Potato Production ◽  
Potato Cultivars ◽  
Root Knot Nematode ◽  
Root Knot Nematodes ◽  
Nematode Reproduction ◽  
Meloidogyne Spp ◽  
Prevalent Species ◽  
Reproduction Factor

Root-knot nematodes (Meloidogyne spp.) significantly impact potato production worldwide and in Brazil they are considered one of the most important group of nematodes affecting potatoes. The objectives of this study were to survey Meloidogyne spp. associated with potatoes in Brazil, determine their genetic diversity and assess the aggressiveness of M. javanica on two susceptible potato cultivars. Fifty-seven root-knot nematode populations were identified using esterase phenotyping, including Meloidogyne javanica, M. incognita, M. arenaria and M. ethiopica. Overall, root-knot nematodes were present in ca 43% of sampled sites, in which M. javanica was the most prevalent species, and the phenotypes Est J3, J2a and J2 occurred in 91.2, 6.7 and 2.1% of the positive samples, respectively. Other species, such as M. incognita, M. arenaria and M. ethiopica, were found less frequently and occurred at rates of 6.4, 4.3 and 2.1% of the samples, respectively. Sometimes, M. javanica was found in mixtures with other root-knot nematodes in ca 10.6% of sites containing Meloidogyne. After confirming the identification of 17 isolates of M. javanica and one isolate each of M. incognita, M. arenaria and M. ethiopica by SCAR markers, the populations were used to infer their genetic diversity using RAPD markers. Results revealed low intraspecifc genetic diversity among isolates (13.9%) for M. javanica. Similarly, M. javanica sub-populations (J2a) clustered together (81% of bootstrap), indicating subtle variation from typical J3 populations. The aggressiveness of four populations of M. javanica from different Brazilian states on two susceptible potato cultivars was tested under glasshouse conditions. Results indicated differences in aggressiveness among these populations and showed that potato disease was proportional to nematode reproduction factor.

scholarly journals A new root-knot nematode, Meloidogyne vitis sp. nov. (Nematoda: Meloidogynidae), parasitizing grape in Yunnan

PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0245201
Author(s):  
Yanmei Yang ◽  
Xianqi Hu ◽  
Pei Liu ◽  
Li Chen ◽  
Huan Peng ◽  
...  
Keyword(s):  
New Species ◽  
Rapid Identification ◽  
Root Knot Nematode ◽  
Morphometric Traits ◽  
Head Region ◽  
Root Knot Nematodes ◽  
Lateral Field ◽  
Sequence Characterized Amplified Region ◽  
Second Stage ◽  
Labial Disc

An unknown root-knot nematode was found at high density on grape roots collected from Yunnan Province. Morphometric traits and measurements, isozyme phenotypes, and molecular analysis clearly differentiated this nematode from previously described root-knot nematodes. This new species is described, illustrated and named Meloidogyne vitis sp. nov. The new species can be distinguished from other Meloidogyne spp. by a unique combination of characters. Females display a prominent neck, an excretory pore is located on the ventral region between 23rd and 25th annule behind lips, an EP/ST ratio of approximately 2.5 (1.98–2.96), a perineal pattern with two large and prominent phasmids, and a labial disc fused with the medial lips to form a dumbbell-shaped structure. Males display an obvious head region, a labial disc fused with the medial lips to form a dumbbell-shaped structure, no lateral lips, a prominent slit-like opening between the labial disc and medial lips, a distinct sunken appearance of the middle of the medial lips, and four incisures in the lateral field. Second-stage juveniles are characterized by a head region with slightly wrinkled mark, a labial disc fused with the medial lips to form a dumbbell-shaped structure, a slightly sunken appearance of the middle of the medial lips, a slit-like amphidial openings between the labial disc and lateral lips, and four incisures in the lateral field. The new species has rare Mdh (N3d) and Est phenotypes (VF1). Phylogenetic analysis based on ITS1-5.8S-ITS2, D2D3 fragments of rDNA, and coxI and coxII fragments of mtDNA sequences clearly separated the new species from other root-knot nematodes, and the closest relative was Meloidogyne mali. Meloidogyne mali was collected for amplifying these sequences as mentioned above, which were compared with the corresponding sequences of new species, the result showed that all of these sequences with highly base divergence (48–210 base divergence). Moreover, sequence characterized amplified region (SCAR) primers for rapid identification of this new species were designed.

scholarly journals A Modern Perspective on Phishing: An investigation into susceptibility to phishing attacks between mobile and desktop email clients

2021 ◽  
Author(s):  
◽  
Jayden Nowitz
Keyword(s):  
Mobile Device ◽  
User Behavior ◽  
Administrative Staff ◽  
Second Stage ◽  
Significant Difference ◽  
Device Type ◽  
Group A ◽  
Group B ◽  
The University ◽  
Modern Perspective

<p>Research on how to counter phishing from a user behavior perspective has been explored for over a decade, yet the prevalence of such threats is increasing. This thesis aims to provide a modern perspective by considering if there is a difference in how susceptible an individual is on a mobile device versus a desktop email client. Currently very few studies consider phishing on mobile devices and the research is unclear as to the potential difference in susceptibility rates between the two device types. Initially a review of 60 phishing emails received by the university that had passed mail filtering were used to assist in the design of the messages to be used in the second stage of the study. Following this a simulated phishing attack on two groups in one unit of professional administrative staff in the university (141 in total with 71 in Group A and 70 in Group B) within the university was undertaken. The defining characteristic between the groups was how they responded to a message with a ‘loss versus gain’ appeal. This area has received limited exploration in the research and findings remain unclear. This study found that people were statistically far more susceptible to the ‘gain’ message of a free coffee at 28.2% than the ‘loss’ message of Office365 account suspension 7.1% . For device type there appears to be no statistically significant difference, even between the groups. This study highlights the complexities of device usage around phishing, that have not been clearly highlighted in previous studies, such as people viewing emails with one device and falling victim on another device.</p>

scholarly journals Assessment of the Potential of Eco-Friendly Nematicides in the Management of Root-Knot Nematodes on French Beans in Kenya

2019 ◽  
Vol 7 (1) ◽  
pp. 62-67
Author(s):  
E. O. Ogumo ◽  
W. M. Muiru ◽  
J. W. Kimenju ◽  
D. M. Mukunya
Keyword(s):  
Reproductive Potential ◽  
Negative Control ◽  
French Bean ◽  
Economic Losses ◽  
Root Knot Nematode ◽  
Population Densities ◽  
Root Knot Nematodes ◽  
French Beans ◽  
Wide Range ◽  
Significant Difference

Root-knot nematodes (RKN) (Meloidogyne spp) are a serious pest causing heavy economic losses in a wide range of agricultural crops. A trial was carried out to evaluate the effectiveness of various eco-friendly nematicides in the management of RKN affecting French bean. The field trial was carried out in two seasons with the following treatments; Rigel-G (salicylic acid), Phyto Protect (Sesame oil extract), Mytech (Paecilomyces lilacinus), Neemraj 0.3% (Azadirachtin), Vydate® (Oxamyl) as a positive control and an untreated control. Various rates; Rigel –G (2.5 ml/l), Phyto Protect (10 l/ha), Mytech (125 g/ha) Neemraj 0.3% (3L/ha) and Vydate® (6 l/ha) of treatments were administered and damage on plants was assessed based on galling indices, crop biomass and yield whereas nematode reproductive potential was assessed based on the J2 counts. There was no significant difference (P ≥ 0.05) in the nematode population densities and galling indices observed among the eco-friendly nematicides and the conventional nematicide (Vydate®). Eco-friendly nematicides had a significant (P ≤ 0.05) reduction of RKN J2 population densities compared to the negative control. The negative control had the highest mean of root-knot nematode densities (240 RKN/200 cc soil) and a galling index of 3.77 while Vydate and Neemraj had the lowest mean density (40 RKN/200 cc soil) in the first season. Similar results were observed in the second season with control having the highest RKN J2 population densities (285 RKN/200 cc soil) and a galling index of 3.89 and Vydate had the lowest (23 RKN/200 cc soil). The results of this study clearly indicate that eco-friendly nematicides can be fully adopted to suppress RKN in French beans as alternatives to conventional nematicides.

scholarly journals Reproduction of Meloidogyne enterolobii in lettuce cultivars of the American group

2015 ◽  
Vol 33 (2) ◽  
pp. 147-150
Author(s):  
Érika CSS Correia ◽  
Norberto Silva ◽  
Marylia GS Costa ◽  
Silvia RS Wilcken
Keyword(s):  
Reproductive Potential ◽  
Egg Mass ◽  
Root Knot Nematodes ◽  
Second Stage ◽  
American Group ◽  
Meloidogyne Enterolobii ◽  
Meloidogyne Spp ◽  
Gall Index ◽  
Summer Time ◽  
Reproduction Factor

Lettuce is the main vegetable cultivated in Brazil, in volume and in marketed value. There are ranges of diseases which may affect lettuce crops, including those caused by root-knot nematodes (Meloidogyne spp.). We evaluated the reproductive potential of Meloidogyne enterolobii in 22 lettuce cultivars. The plants were inoculated with 5,000 eggs and eventuals second stage juveniles of nematode per pot, two days after the transplanting. 'Rutgers' tomato was used as standard for inoculum viability of M. enterolobii. We evaluated, 60 days after inoculation, the gall index, egg mass index and reproduction factor (RF). The 'Ithaca', 'Raider Plus', 'RS-1397', 'L-104', 'Challenge', 'IP-11', 'Classic', 'Salinas 88', 'Vanguard 75', 'Calona' and 'Desert Queen' were resistant to M. enterolobii with RF varying from 0.22 to 0.9, and the cultivars Lady Winterset, Robinson, Sonoma, Raider, Lucy Brown, Bnondaga, Summer Time, Taina, Sundevil and L-109 were susceptible to this nematode, with RF ranging from 1.06 to 5.73.

Comparison of host recognition, invasion, development and reproduction of Meloidogyne graminicola and M. incognita on rice and tomato

Nematology ◽  
2011 ◽  
Vol 13 (5) ◽  
pp. 509-520 ◽  
Author(s):  
Tushar K. Dutta ◽  
Stephen J. Powers ◽  
Brian R. Kerry ◽  
Hari S. Gaur ◽  
Rosane H.C. Curtis
Keyword(s):  
Meloidogyne Incognita ◽  
Host Recognition ◽  
Cortical Region ◽  
Root Knot Nematode ◽  
Root Tips ◽  
Root Knot Nematodes ◽  
Tomato Plants ◽  
Meloidogyne Graminicola ◽  
Second Stage ◽  
Tomato Roots

AbstractThe rice root-knot nematode Meloidogyne graminicola normally infects rice, wheat and several other graminaceous plants. Meloidogyne incognita is a serious pest of dicotyledonous crops, although it can infect and reproduce on some cereals. This paper demonstrates and compares host recognition, development and reproduction of these two species of root-knot nematodes on rice and tomato plants. Attraction bioassays in pluronic gel clearly showed that M. incognita preferred tomato roots to rice or mustard roots, whilst M. graminicola was more attracted towards rice compared with tomato or mustard roots. Based on the attraction data from this study, it can be hypothesised that either: i) the blend of attractants and repellents are different in good and poor hosts; or ii) relatively long-range attractants, together with shorter-range repellents, might affect nematode movement patterns. Some host specific attractants might also be involved. Meloidogyne incognita was able to invade and develop to adult female but did not produce eggs in rice roots. By contrast, M. graminicola developed and reproduced faster on both rice and tomato plants compared with M. incognita. Nevertheless, second-stage juveniles of both these root-knot nematodes showed a similar pattern of distribution inside the roots, preferring to accumulate at the root tips of rice or in the vascular cylinder and cortical region of tomato.

Resistance in Mungbean Against Meloidogyne incognita and its Impact on Nodulation

2020 ◽  
Author(s):  
Narpinderjeet Kaur Dhillon ◽  
Rohit Kumar ◽  
Sukhjeet Kaur ◽  
Anupam Anupam ◽  
Asmita Srari
Keyword(s):  
Plant Growth ◽  
Growth Parameters ◽  
Root Knot Nematode ◽  
Sources Of Resistance ◽  
Kharif Season ◽  
Breeding Programmes ◽  
Meloidogyne Spp ◽  
Moderately Resistant ◽  
The Impact ◽  
Resistant Genotypes

Mungbean is an economically as well as nutritionally enriched crop. Of the different soil borne pathogens attacking mungbean, root-knot nematode (Meloidogyne spp.) is an important pathogen affecting growth and production of mungbean. It is grown in summer as well as in kharif season. The germplasm of mungbean of two seasons’ viz., summer and kharif was screened to identify new sources of resistance against root knot nematode, M. incognita. In addition to screening; studies were also conducted on the impact of root knot nematode infestation in roots on nodulation character of mungbean and growth parameters. Of the sixty three genotypes evaluated in summer, seven were found to be moderately resistant. In kharif season, only three genotypes were found to be moderately resistant. M. incognita infestation was also observed to affect the plant growth parameters as well as nodulation on roots of mungbean genotypes. Comparatively, better plant growth and higher nodulation was observed in moderately resistant genotypes as compared to the susceptible ones. The ten identified moderately resistant genotypes from two seasons can be a useful source in breeding programmes for developing cultivars to manage root knot nematode.

scholarly journals Resistance sources to root-knot nematode Meloidogyne enterolobii in Solanum species

2020 ◽  
pp. 303
Author(s):  
Jadir Borges Pinheiro ◽  
Giovani Olegario da Silva ◽  
Jhenef Gomes de Jesus ◽  
Danielle Biscaia ◽  
Raphael Augusto de Castro e Melo
Keyword(s):  
Solanum Species ◽  
Experimental Unit ◽  
Egg Mass ◽  
Root Knot Nematode ◽  
Sources Of Resistance ◽  
Second Stage ◽  
Randomized Design ◽  
Meloidogyne Enterolobii ◽  
Plant Grown ◽  
Reproduction Factor

The objective of this work was to prospect sources of resistance to root-knot nematode Meloidogyne enterolobii in Solanum species with potential to be used as rootstocks for cultivated Solanaceae. Nine accessions of Solanum sessiliflorum, 27 accessions of S. lycocarpum, 21 accessions of S. acanthodes, 22 accessions of S. scinericum and 26 accessions of S. scuticum for resistance to M. enterolobii. Rutgers and Nemadoro tomatoes were used as susceptible and resistant controls, respectively. The experiment was conducted in a greenhouse at Embrapa Vegetables, Brasília-DF, Brazil, in a completely randomized design with six replications. The experimental unit was a represented by a single plant grown in a plastic pot containing 3 L of substrate. 4000 eggs and eventual juveniles of second stage M. enterolobii were inoculated per pot. At 119 days after inoculation, gall index (Gi), egg mass index (EMI), number of eggs per root gram (NE) and reproduction factor (Fr) were evaluated. Data were subjected to analysis of variance and grouping of treatments by Scott-Knott. It was verified that S. acanthodes and S. Lycocarpum are species with high resistance to M. enterolobii, with accessions being classified identified as immune. S. scuticum also has great potential, as several resistant accessions were identified, although some accessions were quite susceptible; whereas for S. subinerme only 4 resistant accessions were identified, although all others presented a reproduction factor much lower than tomato cv. Nemadoro as control; and all evaluated S. sessiliflorum accessions were susceptible.

scholarly journals IDENTIFICATION OF COWPEA GENOTYPES RESISTANT TO FUSARIUM WILT1

2021 ◽  
Vol 34 (4) ◽  
pp. 957-964
Author(s):  
RISONEIDE DE CÁSSIA ZEFERINO SILVA ◽  
ANTHONY CARLOS DA SILVA ◽  
REZANIO MARTINS CARVALHO ◽  
ANTONIO FÉLIX DA COSTA ◽  
ALESSANDRO NICOLI ◽  
...  
Keyword(s):  
Fusarium Wilt ◽  
Conidial Suspension ◽  
The North ◽  
Randomized Design ◽  
Susceptible Control ◽  
Bean Yield ◽  
Descriptive Scale ◽  
The University ◽  
Moderately Resistant ◽  
Resistant Genotypes

ABSTRACT Fusarium wilt, caused by soil-borne Fusarium oxysporum f. sp. tracheiphilum (Fot), can reduce cowpea bean yield. Considering that genetic control through resistant genotypes is pivotal for Fusarium wilt control, the aim of the present study was to identify cowpea genotypes that are resistant to Fot from the Germplasm Bank of the Pernambuco Agronomic Institute, Embrapa Middle North, and other producing areas in the North and Northeast regions of Brazil. The cultivar BR-17 Gurguéia was used as a susceptible control and MNC01-649F-2-1 was used as a resistant control. Two experiments were carried out in a completely randomized design in the greenhouse of the Department of Agronomy of the University Federal Rural of Pernambuco. Plants with the first pair of expanded leaves were inoculated with a conidial suspension (106 conidia/mL) using the conidia root-immersion methodology. Fusarium wilt severity in plants was assessed 21 d after inoculation, with the aid of a descriptive scale. In the first experiment, we evaluated the resistance of 38 cowpea genotypes, of which 19 (5 moderately resistant and 14 resistant) were selected for the second experiment. In the first experiment, four genotypes (Canapu PE, Miranda IPA 207, Esperança, and BRS Pujante) did not show any symptoms of Fusarium wilt. In the second, 15 genotypes showed high resistance to Fot, including Canapu PE and Miranda IPA 207, which again had no symptoms of Fusarium wilt. In conclusion, this study identified that the genotypes, Canapu PE, Miranda IPA 207, Esperança, and BRS Pujante have greater resistance to Fusarium wilt.

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