scholarly journals Polysulfides Applied as Formulated Garlic Extract to Protect Tomato Plants against the Root-Knot Nematode Meloidogyne incognita

Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 394
Author(s):  
Reinhard Eder ◽  
Erika Consoli ◽  
Jürgen Krauss ◽  
Paul Dahlin

The devastating root-knot nematode Meloidogyne incognita can cause severe damage to field and greenhouse crops. Due to high economic losses, alternative products are essential to replace banned or strictly regulated nematicides that affect human health and/or the environment. Garlic based products have been previously investigated as environmentally friendly nematicides and their active substances, diallyl polysulfides exist as formulated nematicides on the market. We tested the garlic-based nematicide NEMguard® DE as protective of tomato roots. In vitro evaluation of the lethal concentration (LC) showed strong nematicidal activity with LC50 of 0.8 mg/mL after 96 h and LC90 of 1.5 mg/mL. NEMguard® DE showed protective effect against M. incognita as a single application in small pots and a second application further reduced root galling, significantly. Large greenhouse trials were carried out in two consecutive years to test single and monthly applications of NEMguard® DE. In both years, no controlling effect could be observed on M.incognita. We assume that the silt content of the loamy sandy soil used had an effect on the polysulfides, inhibiting their nematicidal effect. We conclude that further experiments are necessary to investigate the nematicidal potential of NEMguard® DE under different soil compositions or as a different formulation.

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

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.


2010 ◽  
Vol 100 (2) ◽  
pp. 199-203 ◽  
Author(s):  
Sergio Echeverrigaray ◽  
Jucimar Zacaria ◽  
Ricardo Beltrão

Nematicidal activity of 22 monoterpenoids were evaluated in vitro and in pot experiments. Twenty of the twenty-two monoterpenoids significantly reduced hatching, and 11 reduced J2 mobility of the root-knot nematode Meloidogyne incognita at a concentration of 250 mg/liter. In general, compounds with hydroxyl and carbonyl groups exhibited higher nematicidal activity than other terpenoids. Borneol, carveol, citral, geraniol, and α-terpineol showed the highest nematicidal activity among the in vitro tested monoterpenoids. These compounds exhibited a dose dependent effect, and drastically reduced eggs hatching and J2 viability at low concentrations. These monoterpenoids, at 100 and 250 mg/kg concentration, diminished root galling of tomato plants in pot experiments. The results suggest that the selected monoterpenoids, and essential oils with high concentration of these compounds, are potential nematicides against Meloidogyne.


Nematology ◽  
2014 ◽  
Vol 16 (8) ◽  
pp. 889-893 ◽  
Author(s):  
Hidetaka Nishiyama ◽  
Satoru Nakagami ◽  
Akihiko Todaka ◽  
Tetsuya Arita ◽  
Takashi Ishida ◽  
...  

Meloidogyne incognita is one of the most detrimental root-knot nematode pests in the world because of its wide range of hosts, infecting almost all plant species. Following infection, this nematode induces gall formation in the root. We have found that these induced galls turn green in tomato roots exposed to light. This gall greening was light-dependent and inhibited by auxin treatment. Chlorophyll was detected in these green galls, and chloroplasts were also observed in the root-knot region. Expression of the chlorophyll a/b-binding protein-4 gene was upregulated in the galls. These results indicate that light treatment induces chloroplast development in tomato plants infected with M. incognita during gall development.


Nematology ◽  
1999 ◽  
Vol 1 (1) ◽  
pp. 95-101 ◽  
Author(s):  
Robin Duponnois ◽  
Amadou M. BÂ ◽  
Thierry Mateille

Abstract Two rhizosphere bacteria, Enterobacter cloacae and Pseudomonas mendocina, were isolated from the rhizosphere of tomato plants growing in a soil heavily infested with both root-knot nematodes and the parasitoid endospore-forming bacterium Pasteuria penetrans. Bacteria E. cloacae and P. mendocina stimulated plant growth, inhibited the reproduction of the root knot nematode Meloidogyne incognita, and increased the attachment of the endospores of P. penetrans on the nematodes in vitro. E. cloacae significantly increased the reproduction of P. penetrans in plant roots. Consequently, the introduction of such bacteria in soils, or cultural practices aimed to increase the activity of native strains of these bacteria, could greatly contribute to the efficiency of nematode biocontrol with P. penetrans. Stimulation de l'activite antagoniste de Pasteuria penetrans envers Meloidogyne incognita par Enterobacter cloacae et Pseudomonas mendocina - Deux bacteries rhizospheriques, Enterobacter cloacae et Pseudomonas mendocina, ont ete isolees a partir de la rhizosphere de plants de tomate preleves dans un sol tres infeste par des nematodes a galles et l'actinomycete Pasteuria penetrans. Les deux souches bacteriennes ont stimule la croissance de la plante, inhibe le developpement du nematode Meloidogyne incognita et augmente in vitro l'attachement des spores de P. penetrans sur la cuticule des nematodes. E. cloacae a significativement stimule la multiplication de P. penetrans dans les racines. En consequence, l'utilisation de telles bacteries pourrait ameliorer de maniere importante l'efficacite de P. penetrans contre les nematodes du genre Meloidogyne.


Plant Disease ◽  
2018 ◽  
Vol 102 (11) ◽  
pp. 2170-2179 ◽  
Author(s):  
Julio Carlos P. Silva ◽  
Vicente P. Campos ◽  
Aline F. Barros ◽  
Marcio P. Pedroso ◽  
Willian C. Terra ◽  
...  

Volatile organic compounds (VOC) produced by green residues for the management of plant-parasitic nematodes are poorly studied for oilseed plants and some Brassica spp. To investigate the activity of VOC in vitro and as biofumigants, dry and aqueous macerates of broccoli (Brassica oleracea var. italica) shoots and sunflower (Helianthus annuus) seed were used against the root-knot nematode Meloidogyne incognita. VOC produced by sunflower seed caused higher mortality of M. incognita second-stage juveniles (J2) than VOC produced by broccoli shoots but both plant species were equally effective in decreasing the infectivity and reproduction of this nematode. The number of galls and eggs produced by the nematode in tomato roots was reduced by 89 and 95%, respectively, on average, at the highest concentrations of broccoli and sunflower seed macerates tested as biofumigants. When nematodes were placed in water exposed to broccoli VOC, J2 immobility increased and the number of galls and eggs produced by the nematode in tomato roots decreased 80 and 96%, respectively. Water exposed to sunflower seed VOC had no effect on the viability of the nematode. Gas chromatography was used to identify five and six chemical groups in broccoli and in sunflower seed macerates, respectively, but only alcohols, sulfurated VOC, and terpenes were detected in the water exposed to these plant macerates. Sulfurated VOC from the water exposed to broccoli macerates were found to be involved in its activity against M. incognita. The purified VOC dimethyl disulfide (DMDS) and 3-pentanol were tested directly against J2 and showed a lethal concentration of 176 and 918 µg/ml (ppm), respectively, whereas dimethyl sulfide had no effect against M. incognita. Furthermore, DMDS and 3-pentanol retained in water killed J2 and reduced gall formation and the number of eggs of M. incognita on tomato roots. Both these plant species produced toxic VOC to M. incognita, whereas only VOC retained in water exposed to broccoli had activity against M. incognita.


2012 ◽  
Vol 102 (3) ◽  
pp. 260-266 ◽  
Author(s):  
A. Martinuz ◽  
A. Schouten ◽  
R. A. Sikora

The root-knot nematode, Meloidogyne incognita, is among the most damaging agricultural pests, particularly to tomato. The mutualistic endophytes Fusarium oxysporum strain Fo162 (Fo162) and Rhizobium etli strain G12 (G12) have been shown to systemically induce resistance toward M. incognita. By using triple-split-root tomato plants, spatially separated but simultaneous inoculation of both endophytes did not lead to additive reductions in M. incognita infection. More importantly, spatially separated inoculation of Fo162 and G12 led to a reduction in Fo162 root colonization of 35 and 39% when G12 was inoculated on a separate root section of the same plant in two independent experiments. In an additional split-root experiment, spatial separation of Fo162 and G12 resulted in a reduction of Fo162 root colonization of approximately 50% over the water controls in two independent experiments. The results suggested that the suppressive activity of G12 on Fo162 and M. incognita is possibly related to the induction of specific plant defense mechanisms. Thus, although Fo162 and G12 have the ability to systemically repress M. incognita infection in tomato, they can be considered incompatible biocontrol agents when both organisms are present simultaneously on the same root system.


2013 ◽  
Vol 103 (8) ◽  
pp. 833-840 ◽  
Author(s):  
Samira Khallouk ◽  
Roger Voisin ◽  
Ulysse Portier ◽  
Joël Polidori ◽  
Cyril Van Ghelder ◽  
...  

Root-knot nematodes (RKNs) (Meloidogyne spp.) are highly polyphagous pests that parasitize Prunus crops in Mediterranean climates. Breeding for RKN-resistant Prunus cultivars, as an alternative to the now-banned use of nematicides, is a real challenge, because the perennial nature of these trees increases the risk of resistance breakdown. The Ma plum resistance (R) gene, with a complete spectrum, and the RMia peach R gene, with a more restricted spectrum, both provide total control of Meloidogyne incognita, the model parthenogenetic species of the genus and the most important RKN in terms of economic losses. We investigated the durability of the resistance to this nematode conferred by these genes, comparing the results obtained with those for the tomato Mi-1 reference gene. In multiyear experiments, we applied a high and continuous nematode inoculum pressure by cultivating nematode-infested susceptible tomato plants with either Prunus accessions carrying Ma or RMia R genes, or with resistant tomato plants carrying the Mi-1 gene. Suitable conditions for Prunus development were achieved by carrying out the studies in a glasshouse, in controlled conditions allowing a short winter leaf fall and dormancy. We first assessed the plum accession ‘P.2175’, which is heterozygous for the Ma gene, in two successive 2-year evaluations, for resistance to two M. incognita isolates. Whatever the isolate used, no nematodes reproducing on P.2175 were detected, whereas galls and nematodes reproducing on tomato plants carrying Mi-1 were observed. In a second experiment with the most aggressive isolate, interspecific full-sib material (P.2175 × [‘Garfi’ almond × ‘Nemared’ peach]), carrying either Ma or RMia (from Nemared) or both (in the heterozygous state) or neither of these genes, was evaluated for 4 years. No virulent nematodes developed on Prunus spp. carrying R genes, whereas galling and virulent individuals were observed on Mi-1-resistant tomato plants. Thus, the resistance to M. incognita conferred by Ma in Prunus material in both a pure-plum and an interspecific genetic background, or by RMia in an interspecific background, appears to be durable, highlighting the value of these two genes for the creation of Prunus rootstock material.


2020 ◽  
Vol 21 (3) ◽  
Author(s):  
I Gede Swibawa I Gede ◽  
YUYUN FITRIANA ◽  
SOLIKHIN ◽  
RADIX SUHARJO ◽  
F.X. SUSILO ◽  
...  

Abstract. Swibawa IG, Fitriana Y, Solikhin, Suharjo R, Susilo FX, Rani E, Haryani MS, Wardana RA. 2020. Morpho-molecular identification and pathogenicity test on fungal parasites of guava root-knot nematode eggs in Lampung, Indonesia. Biodiversitas 21: 1108-1115. This study aimed to obtain and discover the identity of the species of fungal egg parasites of root-knot nematodes (RKN), which have a high pathogenic ability causing major losses in vegetable crops. The exploration of the fungi was carried out in 2016 and 2018 from Crystal guava plantations in East Lampung, Central Lampung, Tanggamus, and NirAma, a commercial product that has been used for controlling Meloidogyne sp. in Indonesia. Identification was carried out based on morphological characteristics and molecular-based gene sequential analysis of Intergenic Transcribed Spacer (ITS) 1 and ITS 4. A pathogenicity test was carried out in vitro and in a greenhouse using tomato plants as indicator plants. In the in vitro test, observations were made on the percentage of infected RKN eggs. The observations in the greenhouse test were carried out on RKN populations in the soil and roots of tomato plants, root damage (root knots), and damage intensity due to RKN infection. The exploration resulted in five isolates of fungal egg parasites of RKN from the guava plantations in East Lampung (2), Central Lampung (1), Tanggamus (1), and from the isolation results of commercial products (1). The isolates were given codes as B4120X (PT GGP PG1), B3010 (PT GGP PG4), B412G (PT GGP PG 4), B01TG (Tanggamus), and BioP (Commercial products). Based on their morphological characteristics, the isolates were classified into the genus of Paecilomyces. The results of molecular identification showed that the discovered fungi were Purpureocillium lilacinum (Thom.) Luangsa Ard. (Syn. Paecilomyces lilacinus (Thom.) Samson.). Based on the in vitro tests, the five fungal isolates were able to parasitize RKN eggs at 86.4-100%. In the greenhouse test, all isolates significantly suppressed nematode populations in the soil and tomato roots, inhibited the formation of root knots, and produced lower damage intensity compared to controls. Among all the isolates tested, B01TG had the best ability to infect nematode eggs (99.5%), suppressing the formation of root knots, nematode population in the soil and the roots of tomato plants, and the damage intensity compared to other isolates.


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