scholarly journals Screening Selected Solanum Plants as Potential Rootstocks for the Management of Root-Knot Nematodes (Meloidogyne incognita)

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Benjamin A. Okorley ◽  
Charles Agyeman ◽  
Naalamle Amissah ◽  
Seloame T. Nyaku

Root-knot nematodes (RKNs) (Meloidogyne spp.) represent agricultural pest of many economic crops, including tomatoes and potatoes. They advance a complex parasitic relationship with roots of tomato plants leading to modification of host structural and physiological functions in addition to significant yield loss. Resistance in solanaceous plants to RKNs has been identified and associated with the possession of Mi gene. The reaction of four Solanum rootstocks (S. aethiopicum L., S. macrocarpon L., S. lycopersicum L.“Mongal F1,” and S. lycopersicum L. “Samrudhi F1”) was evaluated in pots and in a natural Meloidogyne spp.-infested field in a two-year trial (2015–2016), to identify RKN-resistant rootstock(s), which can be utilized in tomato grafting as a management measure against these nematodes. A rootstock’s reaction to RKNs was assessed using root gall scores (GSs), egg count/g of root, and reproductive factors (Rfs) at the end of 6 and 12 weeks after transplanting (wat) in infested fields, respectively. Solanum macrocarpon, S. aethiopicum, and Mongal F1 showed tolerant responses with reduced root galling and low to high reproductive factors in pot and field experimentation. Although Samrudhi F1 was resistant in both pot and field trials and consistently decreased nematode root galling (<1.00) and reproduction (Rf < 1.00), it failed to significantly increase yield, as compared with the highest yield obtained by the tolerant rootstock, Mongal F1 (870.3 and 1236.6 g/plant, respectively). Evaluation of the four rootstocks against four (0, 500, 1,000, and 5000) RKN inocula levels (Juveniles) showed no significant differences among the growth parameters (fresh and dry shoot and root weights). Root-knot nematode-susceptible tomato varieties, for example, Pectomech F1, a popular tomato variety in Ghana, can be grafted onto the RKN-resistant and RKN-tolerant rootstocks for increased yields.

1982 ◽  
Vol 22 (117) ◽  
pp. 357 ◽  
Author(s):  
GR Stirling ◽  
MF Wachtel

The performance of 15 potentially useful nematode-resistant tomato varieties (Ace Hy, Better Boy, Bigset, Bonus, Calmart, Magnifico, Monte Carlo, Patriot, Red Supreme, Rich Reward, Surprise, Terrific, VFN Bush, VFN 8 and Vine Ripe) was assessed in field trials at Loveday and Loxton, South Australia. All varieties showed some nematode resistance when grown in sites heavily infested with root-knot nematodes (Meloidogyne javanica) and most produced yields which were not significantly less than the commonly used susceptible varieties (Burnley Gem, Floradade, Grosse Lisse and Q3) grown in soil treated with nematicides. However, the nematode-resistant varieties were of limited value commercially because the fruit was either susceptible to cracking or too soft to be transported long distances. In glasshouse tests, biotypes of root-knot nematode capable of attacking resistant varieties were not observed. All resistant varieties exhibited resistance against populations of M. javanica from grape, peach, sweet corn, tomato (variety Floradade), tomato (variety VFN Bush), and against field populations of Meloidogyne from both resistant and susceptible tomato varieties. These results suggest that agronomically acceptable nematode-resistant varieties would be useful in management programs to control root-knot nematodes in the Murray Valley.


2019 ◽  
Vol 7 (2) ◽  
pp. 240
Author(s):  
Joshua K. Njenga ◽  
Geofrey K. Gathungu ◽  
Jesca N. Mbaka

Root-knot nematodes (Meloidogyne spp.) are a major problem in French bean production within the smallholder farming systems. Control of root-knot using synthetic nematicides is not viable due to environmental concerns relating to their toxic residues. There is need to develop alternative control options that will promote soil health and reduce parasitic nematode densities. A study was conducted to determine the efficacy of Neem (Azadirachta indica A. Juss), Tithonia (Tithonia diversifolia) and Tephrosia (Tephrosia purpurea) leaf extracts in management of root-knot. Controlled lath house and field trials were conducted where the treatments were extracts from Neem, Tithonia and Tephrosia at different concentration levels of 25 ml/L, 50 ml/L and 100 ml/L). Vydate (Oxamyl 10%) a synthetic nematicide served as a standard positive control while treatments with no extracts application and no nematode application served as negative controls. The treatments in the lath house were arranged in completely randomized design while the field trials were arranged in randomized complete block design. Fench beans were planted on nematode infested soils and data on root galling indices and yield components was collected. Data collected was subjected to analysis of variance and significantly different means separated using Tukey’s Studentized Range Test at P=0.05. The extracts evaluated reduced root galling with their efficacy being similar to that of Vydate® (Oxamyl 10%) which was used as a positive control. Neem extracts treatments had the lowest mean galling index of the extracts, followed by Tithonia. Root-knot nematode galling indices were highest in the untreated control at 10 both in trial I and trial II. Treatment trials from Neem and Tithonia at concentration levels of 100 ml/L resulted in highest yield of French beans while yield from the untreated plants were the lowest. The results indicate extracts can be adopted to suppress root-knot nematodes.


2020 ◽  
Vol 30 (1) ◽  
Author(s):  
Ghena Mamdouh AbdelRazek ◽  
Rabaa Yaseen

Abstract Background Root-knot nematodes are among the world’s most damaging endoparasitic sedentary nematodes, especially, Meloidogyne incognita that infects a wide range of plant hosts. The activity of different antagonistic bacteria was studied for the low-cost and eco-friendly management of M. incognita on eggplant. Main body Twenty-five isolates were isolated from rhizosphere soils infected with nematodes. Of these, 6 isolates displayed the highest activity, demonstrating 100% mortality of J2 nematodes under laboratory conditions. Partial sequencing of 16S rRNA gene and phylogenetic analysis was used to identify the selected isolates and they were found to be Paenibacillus amylolyticus, Brevibacillus agri, Gluconobacter frateurii, Beijerinckia mobilis, Achromobacter aloeverae, and Pseudomonas stutzeri. The abilities of the selected isolates to produce hydrogen cyanide, siderophores, chitinase, protease, indole acetic acid, and to dissolve phosphorus were also detected. Conclusion The results of the greenhouse experiment indicated that all the tested bacteria had a greatly significant effectiveness for suppressing root-knot nematode M. incognita. Application of all the rhizosphere bacteria and their combinations reduced the number of galls, number of juveniles, egg-masses, eggs, females, and total final population. All bio-agent treatments succeeded in improving the plant growth parameters and increased the microbial density in eggplant rhizosphere.


Plant Disease ◽  
2019 ◽  
Vol 103 (9) ◽  
pp. 2392-2396 ◽  
Author(s):  
J. O. Becker ◽  
A. Ploeg ◽  
J. J. Nuñez

California grows approximately 80% of the U.S. carrot production. The primary production challenges derive from root-knot nematodes (Meloidogyne spp.). Between 2013 and 2016, we evaluated three novel fluorinated nonfumigant nematicides in five field trials. Fluensulfone, fluopyram, and fluazaindolizine were applied as product-ready formulations at various rates, dates, and formulations. They were rated for their efficacy against the Southern root-knot nematode (M. incognita), their ability to mitigate nematode-caused crop damage, and potential to produce marketable carrot yield under high disease pressure. All trials were conducted in randomized complete block designs in M. incognita–infested, sandy-loam fields. Soil population of M. incognita at seeding and harvest, midseason plant vigor and fibrous root galling, harvest taproot galling, and marketable carrot yield were analyzed by ANOVA. Midseason gall ratings were indicative of disease ratings at harvest. All fluazaindolizine and fluensulfone treatments reduced at-harvest galling compared with the untreated controls. Fluopyram resulted in less galling but did not sufficiently protect the lower part of the taproot. Overall, fluazaindolizine at 2.24 kg/ha resulted in the most consistent and highest marketable carrot yield, followed by fluensulfone at 2.95 kg/ha. Both fluazaindolizine and fluensulfone will likely provide effective and target-selective crop protection against root-knot nematodes in fresh carrot production.


Plant Disease ◽  
2010 ◽  
Vol 94 (8) ◽  
pp. 1015-1021 ◽  
Author(s):  
C. L. Rivard ◽  
S. O'Connell ◽  
M. M. Peet ◽  
F. J. Louws

Southern blight (Sclerotium rolfsii) and root-knot nematodes (Meloidogyne spp.) cause severe damage to fresh-market tomato (Solanum lycopersicum) throughout the southeastern United States. Grafting is an emerging technology in U.S. tomato production, and growers require information regarding the resistance characteristics conferred by rootstocks. In this study, southern blight (SB) and root-knot nematodes (RKN) were effectively managed using interspecific hybrid rootstocks. During 2007 and 2008, field trials were carried out at two locations that had soils naturally infested with S. rolfsii. At the end of the growing seasons, the mean SB incidence of nongrafted plants was 27 and 79% at the two sites. SB incidence among plants grafted onto rootstock cultivars Big Power (one location only), Beaufort, and Maxifort ranged from 0 to 5%, and area under the disease progress curve (AUDPC) values were lower than for nongrafted and self-grafted controls (P < 0.01). At one location, soils were naturally infested with RKN, and all three rootstocks reduced RKN AUDPC and RKN soil populations at first harvest (P < 0.01). Big Power was particularly effective at reducing RKN galling and RKN soil populations at final fruit harvest (P < 0.01). Fruit yield was higher when resistant rootstocks were utilized (P < 0.05), and in our study grafting was effective at maintaining crop productivity in soils infested with S. rolfsii and M. incognita.


Author(s):  
Thomas Assinger ◽  
Stefano F. F. Torriani ◽  
Salvatore Accardo ◽  
James Fountaine ◽  
Siegrid Steinkellner

AbstractRamularia collo-cygni B. Sutton and J.M. Waller is a major disease in Austrian barley-growing regions. To date, fungicide application is the most effective method to manage the disease; however, fungicide resistance to demethylation and succinate dehydrogenase inhibitors has developed over the last few years. In the growing seasons 2016/2017 and 2017/2018, field trials were carried out to analyze the efficiency of fungicide strategies based on different fungicide classes. Disease development, growth parameters and monitoring of CYP51 and sdh mutations were determined. Fungicide treatments resulted in higher disease control, green leaf area and grain yield. In Austrian R. collo-cygni field populations, the frequency of the mutations CYP51-I325T and CYP51-I328L was low to moderate. Frequency of mutations sdhC-H146R and sdhC-H153R was low. Frequencies of CYP51-I325T and -I328L were similar and increased following DMI application. Frequency of sdhC-H146R was higher compared to sdhC-H153R. The SDHI benzovindiflupyr showed a higher selection rate for sdh mutations compared to bixafen. These sdh mutations were not selected if chlorothalonil was used as mixing partner, leading to a stable composition of sdh resistance alleles over the last two years. Chlorothalonil was proven to be an effective tool for anti-resistance strategies. Currently, SDHIs and DMIs are the backbone of Ramularia leaf spot control in Austria; however, the level of resistance is likely to increase in absence of suitable anti-resistance strategies and following the ban of chlorothalonil.


1972 ◽  
Vol 23 (4) ◽  
pp. 623
Author(s):  
EM Hutton ◽  
WT Williams ◽  
LB Beall

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.


1999 ◽  
Vol 29 (2) ◽  
pp. 42-45 ◽  
Author(s):  
Kazuyoshi CHUBACHI ◽  
Makoto FURUKAWA ◽  
Shigeaki FUKUDA ◽  
Senji TAKAHASHI ◽  
Shoji MATSUMURA ◽  
...  

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 ◽  
2017 ◽  
Vol 19 (1) ◽  
pp. 69-80 ◽  
Author(s):  
Israel L. Medina ◽  
Cesar B. Gomes ◽  
Valdir R. Correa ◽  
Vanessa S. Mattos ◽  
Philippe Castagnone-Sereno ◽  
...  

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.


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