scholarly journals Heterologous Expression of the Mi-1.2 Gene from Tomato Confers Resistance Against Nematodes but Not Aphids in Eggplant

2006 ◽  
Vol 19 (4) ◽  
pp. 383-388 ◽  
Author(s):  
Fiona L. Goggin ◽  
Lingling Jia ◽  
Gowri Shah ◽  
Stephanie Hebert ◽  
Valerie M. Williamson ◽  
...  

The Mi-1.2 gene in tomato (Solanum lycopersicum) is a member of the nucleotide-binding leucine-rich repeat (NB-LRR) class of plant resistance genes, and confers resistance against root-knot nematodes (Meloidogyne spp.), the potato aphid (Macrosiphum euphorbiae), and the sweet potato whitefly (Bemisia tabaci). Mi-1.2 mediates a rapid local defensive response at the site of infection, although the signaling and defensive pathways required for resistance are largely unknown. In this study, eggplant (S. melongena) was transformed with Mi-1.2 to determine whether this gene can function in a genetic background other than tomato. Eggplants that carried Mi-1.2 displayed resistance to the root-knot nematode Meloidogyne javanica but were fully susceptible to the potato aphid, whereas a susceptible tomato line transformed with the same transgene was resistant to nematodes and aphids. This study shows that Mi-1.2 can confer nematode resistance in another Solanaceous species. It also indicates that the requirements for Mi-mediated aphid and nematode resistance differ. Potentially, aphid resistance requires additional genes that are not conserved between tomato and eggplant.

2019 ◽  
Vol 37 (1) ◽  
pp. 17-21 ◽  
Author(s):  
Jéssica Cardoso ◽  
Luiza Tonelli ◽  
Talita S Kutz ◽  
Fernanda D Brandelero ◽  
Thiago de O Vargas ◽  
...  

ABSTRACT Intensive production of vegetables in greenhouses can increase the amount of inoculum of soil-borne pathogens, such as the root-knot nematode. Thus, in this study we aimed to evaluate the potential of Solanaceae as rootstocks resistant to Meloidogyne javanica nematodes as an alternative to tomato grafting. The experiment consisted of seven treatments: wild species joá-vermelho (Solanum capsicoides), joá-bagudo (Solanum palinacanthum), joá-bravo (Solanum viarum), jurubeba (Solanum spp.) and the commercial tomato cultivars Santa Cruz Kada, Batalha and Guardião. The analyzed variables were gall index; egg mass index; final nematode population; reproduction factor (FR) and reaction: susceptibility, resistance and immunity; fresh shoot and root mass and number of eggs per gram of roots. The wild species joá-vermelho, joá-bagudo and jurubeba showed resistance, with the lowest indexes of galls, egg mass, final population of nematodes and number of eggs per gram of root, not differing from the resistant control treatment (hybrid rootstock Guardião), with a reproduction factor less than 1, showing potential to be used as a resistant rootstock to M. javanica. Joá-bravo species showed susceptibility to the root-knot nematode, with a FR>1, not differing from the susceptible tomato Santa Cruz Kada. These results confirm the resistance of wild species to nematode parasitism, which can prove the viability of use as possible alternative rootstocks, and reinforce the idea that more studies should be carried out aiming to provide more viable options for farmers and plantlet producers.


Author(s):  
Taketo Fujimoto ◽  
Hiroshi Abe ◽  
Takayuki Mizukubo ◽  
Shigemi Seo

Root-knot nematodes (RKNs; Meloidogyne spp.) parasitize the roots and/or stems of a wide range of plant species, resulting in severe damage to the parasitized plant. The phytohormone ethylene (ET) plays an important role in signal transduction pathways leading to resistance against RKNs. However, little is currently known about the induction mechanisms of ET-dependent RKN resistance. Inoculation of Arabidopsis (Arabidopsis thaliana) roots with RKNs decreased chlorophyll contents in aerial parts of the plant. We observed accumulation of phytol, a constituent of chlorophyll and a precursor of tocopherols, in RKN-parasitized roots. Application of sclareol, a diterpene that has been shown to induce ET-dependent RKN resistance, to the roots of Arabidopsis plants increased phytol contents in roots accompanied by a decrease in chlorophyll in aerial parts. Exogenously applied phytol inhibited RKN penetration of roots without exhibiting nematicidal activity. This phytol-induced inhibition of RKN penetration was attenuated in the ET-insensitive Arabidopsis mutant ein2-1. Exogenously applied phytol enhanced the production of α-tocopherol and expression of VTE5, a gene involved in tocopherol production, in Arabidopsis roots. α-Tocopherol exerted similar induction of RKN resistance as phytol and showed increased accumulation in roots inoculated with RKNs. Furthermore, the Arabidopsis vte5 mutant displayed no inhibition of RKN penetration in response to phytol. These results suggest that exogenously applied phytol induces EIN2-dependent RKN resistance, possibly via tocopherol production.


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.


HortScience ◽  
2000 ◽  
Vol 35 (7) ◽  
pp. 1333-1337 ◽  
Author(s):  
Jorge Pinochet ◽  
Carolina Fernández ◽  
Cinta Calvet ◽  
Adriana Hernández-Dorrego ◽  
Antonio Felipe

Twenty-nine commercial and experimental Prunus rootstocks, most with incorporated root-knot nematode [Meloidogyne javanica (Traub.) Chitwood] resistance, were evaluated against mixtures comprising nine populations of the root-lesion nematode Pratylenchus vulnus Allen and Jensen. Nearly all tested materials were susceptible. Five cultivars with high resistant levels were further challenged with seven P. vulnus populations individually. `Redglow' (Prunus salicina Lindl. × P. munsoniana Wight and Hedrick) was the only rootstock that showed broad resistance to all populations. The rootstocks `Torinel' (P. domestica L.), AC-595 (P. domestica × P. insititia L.), `Marianna 4001' (P. cerasifera Ehr. × P. munsoniana), and `Felinem' [P. dulcis (Mill.) D. A. Webb × P. persica (L.) Batsch] showed resistance to one or a few P. vulnus populations. Several supposedly resistant sources proved to be susceptible. Tests of crosses made between parents of diverse genetic background with partial resistance to P. vulnus indicate that a descendant with potential P. vulnus resistance is difficult to obtain. Pathogenic diversity among P. vulnus populations appears to be high.


HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 622a-622 ◽  
Author(s):  
W. R. Maluf ◽  
S. M. Azevedo ◽  
V.P. Campos

Heritabilities for resistance to root knot nematodes (Meloidogyne javanica and Meloidogyne incognita races 1, 2, 3, and 4) were studied in a population of 226 sweetpotato clones of diverse origin. For each nematode isolate tested, 128-cell speedling trays were filled with previously inoculated substrate (30000 eggs/1000 mL substrate). Sweetpotato clones suitably tagged and identified were randomly planted in the cells (one plant/cell), with a total of four plants per clone per isolate. Ninety days after inoculation, sweetpotato plants had their roots washed for substrate removal, and treated with 150 mg·L–1 Phloxine B to stain nematode egg masses. The number of egg masses per root was recorded, and plants were accordingly assigned scores from 0 (highly resistant) to 5 (highly susceptible). Broad-sense heritability estimates were 0.87, 0.91, 0.81, 0.95, and 0.93 respectively for resistance to M. javanica and races 1, 2, 3, and 4 of M. incognita. The frequencies of resistant genotypes were higher for M. javanica and lower for M. incognita race 2. Genotypic correlations (rG) among the resistances to the various Meloidogyne isolates utilized were weak, ranging from 0.11 to 0.57, suggesting independent genetic controls. Clones could be selected, however, with high levels of resistance to all nematode isolates tested. (This work was supported by CNPq, CAPES, FAPEMIG, and FAEPE/UFLA.)


2019 ◽  
Vol 37 ◽  
Author(s):  
C. BELLÉ ◽  
T.E. KASPARY ◽  
R.R. BALARDIN ◽  
R.F. RAMOS ◽  
Z.I. ANTONIOLLI

ABSTRACT: The frequency of species of root-knot nematodes (Meloidogyne spp.) was evaluated in weeds collected in different fallow farms in the State of Rio Grande do Sul, Brazil. In the samples where the nematode was found, the species of the root-knot nematode was identified by electrophoresis using the isozyme esterase. They were obtained from weeds belonging to 24 weed species from 13 different botanical families: Amaranthaceae, Asteraceae, Commelinaceae, Convovulaceae, Cyperaceae, Euphorbiaceae, Lamiaceae, Malvaceae, Oxalidaceae, Poaceae, Portulacaceae, Solanaceae, Verbenaceae. Meloidogyne javanica Est J3 (Rm: 1.0, 1.25, 1.40) was the most frequent species and occurred in 53.3% of the samples. M. arenaria with phenotype Est. A2 (Rm: 1.20, 1.30) was detected in 15.6% of the samples. M. incognita Est. I2 (Rm: 1.0, 1.1), M. ethiopica Est. E3 (Rm: 0.9, 1.15, 1.30), M. enterolobii Est. M2 (Rm: 0.7, 0.75, 0.9, 0.95) and M. hapla Est. H1 (Rm: 1.17) in 13.3%, 8.9%, 6.7% and 2.2% of the samples, respectively. Therefore, knowledge of the range of host plants to different species of the root-knot nematode can positively contribute to the adoption of management practices that allow the reduction of their populations in the soil.


2003 ◽  
Vol 16 (7) ◽  
pp. 645-649 ◽  
Author(s):  
Gloria Nombela ◽  
Valerie M. Williamson ◽  
Mariano Muñiz

The tomato gene Mi-1.2 confers resistance against root-knot nematodes and some isolates of potato aphid. Resistance to the whitefly Bemisia tabaci previously has been observed in Mi-bearing commercial tomato cultivars, suggesting that Mi, or a closely linked gene, is responsible for the resistance. The response of two biotypes of B. tabaci to tomato carrying the cloned Mi was compared with that of the isogenic untransformed tomato line Moneymaker. Our results indicate that Mi-1.2 is responsible for the resistance in tomato plants to both B- and Q- biotypes. Mi-1.2 is unique among characterized resistance genes in its activity against three very different organisms (root-knot nematodes, aphids, and whiteflies). These pests are among the most important on tomato crops worldwide, making Mi a valuable resource in integrated pest management programs.


1967 ◽  
Vol 7 (29) ◽  
pp. 580 ◽  
Author(s):  
MR Sauer

Sultana vines grafted on rootstocks with slight to moderate resistance to root knot nematode, Meloidogyne javanica (Treub) Chitwood, were planted in root knot infested sandy loam soil in an established vineyard that had been fumigated with DD at 20 gallons an acre immediately after old vines were removed. Over a seven-year period vigorous high yielding vines were produced on the rootstocks 101-14 and Rupestris du Lot. An off type 101-14 and 420A were less successful. Ungrafted sultana vines in the same soil matched grafted vines in growth for three or four years, then failed to keep pace. Total yields from vines on 101-14 and du Lot in the fifth to seventh seasons were twice the yields of the ungrafted, and differences in growth appear to be increasing. Because of better growth habit and higher nematode resistance 101-14 is preferred to du Lot.


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