خيارات البحث
النتائج 1 - 10 من 365
Epicauta vittata (Fabricius): occurrence in tomato plant and weeds in the State of Rondônia النص الكامل
2020
Claudemir Schwanz Turcato | Freddy Melo Toledo | Emanoel Pereira Sampaio | Cleiton Dias Alves | Vando Miossi Rondelli | Jairo Rafael Machado Dias | Fábio Régis de Souza
The tomato (Solanum lycopersicum L.) plant stands out for being a species cultivated throughout the national territory, being the most important vegetable in Brazil, from the socioeconomic point of view. However, it has been one of the crops most affected by phytosanitary problems. For example, there are the pest insects of the genus Epicauta (Coleoptera: Meloidae). Thus, the objective of this study was to record the occurrence of a pest insect (beetle) harming vegetative growth and productive performance in the fresh-market tomato crop and feeding on weeds. The tomato plants were found on “jurubeba” (Solanum paniculatum L.) rootstock, spaced 1.0 m x 0.5 m, grown in the municipality of Rolim de Moura, Rondônia state. The insect-pest (beetle) was identified as Epicauta vittata (Fabricius). It was observed that the damages caused by the larvae occurred in the main stem of the tomato, only above the grafting site, causing boring, however no damage was observed in the rootstock (“jurubeba”). Adult insects caused defoliation in both tomato plant and joyweed (Alternanthera tenella Colla), slender amaranth (Amaranthus viridis L.), “trapoeraba” (Commelina benghalensis L.) and morning glory (Ipomoea purpurea [L.]). High population of E. vittata causes severe damages to tomato, damaging the vegetative growth and productive performance of the crop, however does not affect the root system when grafted with “jurubeba” (S. paniculatu). Epicauta vittata in the adult phase is fed alternately of weeds.
اظهر المزيد [+] اقل [-]Impact of climate change on water and nitrogen use efficiencies of processing tomato cultivated in Italy النص الكامل
2020
Cammarano, D. | Ronga, D. | Di Mola, I. | Mori, M. | Parisi, M.
Tomato (Solanum lycopersicum L.) is a globally important vegetable recognized for its positive health benefits. As most of the vegetable production, tomato require significant amount of agronomic inputs. However, recent shifts in climate patterns in terms of timing and amount in rainfall, patterns in air temperature, and the associated extreme events have caused harm and disruption to the agricultural sector worldwide. The objective of this study was to: i) evaluate the ability of a crop simulation model to simulate yield and growth parameter of a processing tomato in South west Italy; ii) quantify the impacts of projected climate on business as usual agronomic practices; iii) understand the role of projected changes and increased CO₂ on the water and nutrient efficiency. Field trials from an open field at Sele Valley (40°35′03.8″ N, 14°58′48.6″ E) (Salerno, South west Italy) during a two-year period (2004–2005) were used. Baseline climate data (1984–2018) were available and four contrasting projections were selected as function of their spread in terms of changes in growing season rainfall and temperature respect to the baseline. The crop model DSSAT (Decision Support System of Agrotechnology Transfer) was used for this study. The model was able to simulate tomato response to N fertilization with acceptable error levels respect to the ones reported in literature. The projected increase in air temperature and changes in rainfall caused a shortening ranging from 1.5 to 3 days in tomato phenology causing an overall 15 % reduction in tomato yield. To offset the negative impact of rainfall and temperature changes, additional irrigation water (from 85 to 110 mm) and nitrogen rate (from 20 to 30 kg N ha⁻¹) is needed. However, the increase in irrigation water does not translate in significant yield increase and caused an increase in water and nitrogen use efficiency of less than 10 %.
اظهر المزيد [+] اقل [-]Biogenic AgNPs—A Nano Weapon against Bacterial Canker of Tomato (BCT) النص الكامل
2020
Asma Noshad | Mudassar Iqbal | Crispin Hetherington | Hassan Wahab
Biogenic AgNPs—A Nano Weapon against Bacterial Canker of Tomato (BCT) النص الكامل
2020
Asma Noshad | Mudassar Iqbal | Crispin Hetherington | Hassan Wahab
Bacterial canker of tomato caused by the bacterial pathogen Clavibacter michiganensis subsp. michiganensis (Cmm) is a major limiting factor for tomato production worldwide. Currently there exists no resistant variety of tomato to bacterial canker; only cultural and chemical controls are available. This study synthesized AgNPs (silver nanoparticles) via a green chemistry route and investigated their bactericidal potential against bacterial canker of tomato (BCT). AgNPs were prepared using mycellial aqueous extract of agriculturally beneficial fungi Pythium oligandrum. The formation of AgNPs was confirmed by using UV–Vis spectroscopy for the absorbance pattern while their morphology was investigated by the transmission electron microscopy (TEM). The X-ray diffraction profile for the biogenic AgNPs confirmed a crystalline structure with an average particle size of 12 nm. AgNPs treated seeds showed a normal germination rate with normal seedling growth. An in-vitro study found that the prepared AgNPs caused the maximum inhibition of the bacterial pathogen. In the greenhouse the introduction of AgNPs significantly prevents and inhibits the bacterial pathogen Cmm on tomato plants. These results suggest that this process is a strong candidate for industrial scale production of AgNPs. These particles act as an inhibitor and broad spectrum antibacterial agent against cmm, and hence offer a new and eco-friendly alternative in BCT control.
اظهر المزيد [+] اقل [-]Biogenic AgNPs—A Nano Weapon against Bacterial Canker of Tomato (BCT) النص الكامل
2020
Noshad, Asma | Iqbal, Mudassar | Hetherington, Crispin | Wahab, Hassan
Bacterial canker of tomato caused by the bacterial pathogen Clavibacter michiganensis subsp. michiganensis (Cmm) is a major limiting factor for tomato production worldwide. Currently there exists no resistant variety of tomato to bacterial canker; only cultural and chemical controls are available. This study synthesized AgNPs (silver nanoparticles) via a green chemistry route and investigated their bactericidal potential against bacterial canker of tomato (BCT). AgNPs were prepared using mycellial aqueous extract of agriculturally beneficial fungi Pythium oligandrum. The formation of AgNPs was confirmed by using UV–Vis spectroscopy for the absorbance pattern while their morphology was investigated by the transmission electron microscopy (TEM). The X-ray diffraction profile for the biogenic AgNPs confirmed a crystalline structure with an average particle size of 12 nm. AgNPs treated seeds showed a normal germination rate with normal seedling growth. An in-vitro study found that the prepared AgNPs caused the maximum inhibition of the bacterial pathogen. In the greenhouse the introduction of AgNPs significantly prevents and inhibits the bacterial pathogen Cmm on tomato plants. These results suggest that this process is a strong candidate for industrial scale production of AgNPs. These particles act as an inhibitor and broad spectrum antibacterial agent against cmm, and hence offer a new and eco-friendly alternative in BCT control.
اظهر المزيد [+] اقل [-]Phenylacetic Acid and Methylphenyl Acetate From the Biocontrol Bacterium Bacillus mycoides BM02 Suppress Spore Germination in Fusarium oxysporum f. sp. lycopersici النص الكامل
2020
Je-Jia Wu | Je-Jia Wu | Jenn-Wen Huang | Jenn-Wen Huang | Wen-Ling Deng | Wen-Ling Deng
Bacillus mycoides strain BM02 originally isolated from the tomato rhizosphere was found to have beneficial functions in tomato by promoting plant growth and reducing the severity of Fusarium wilt caused by Fusarium oxysporum f. sp. lycopersici (Fol). Cytological experiments demonstrated B. mycoides BM02 reduced Fol invasion by reducing spore attachment and increasing hyphal deformation in hydroponics-grown tomato root tissues. Two volatile antifungal compounds, phenylacetic acid (PAA) and methylphenyl acetate (MPA), were identified from the culture filtrates of B. mycoides BM02 by GC-MS analysis. Chemically synthesized PAA, and to a lower extent MPA, suppressed spore germination but have no effects on the hyphal growth of Fol. Our results indicated that the biocontrol agent B. mycoides BM02 produced an array of bioactive compounds including PAA and MPA to suppress plant diseases caused by Fol and other pathogenic microorganisms.
اظهر المزيد [+] اقل [-]Tomato chlorosis virus and Tomato yellow leaf curl virus CAUSING MIXED INFECTION IN PROTECTED EGGPLANT (Solanum melongena) CROPS IN TURKEY | Tomato chlorosis virus and Tomato yellow leaf curl virus CAUSING MIXED INFECTION IN PROTECTED EGGPLANT (Solanum melongena) CROPS IN TURKEY النص الكامل
2020
Fidan, Hakan | Sarıkaya, Pelin
Eggplant (Solanum melongena) is an important source of food for people. Eggplant cultivations, located in the Mediterranean region province of Antalya, corresponds to 20% of the total eggplant production in Turkey. In Antalya province, yellowing type symptoms were observed in eggplant areas and it was found that these symptoms were not caused by fungal or bacterial cause. The yellowing symptoms characteristic for Solanaceae family, such as tomato and pepper, are also observed in the same family of eggplant. Total nucleic acids were obtained from infected eggplants were tested by RT-PCR/PCR with specific primers of TYLCV (Tomato yellow leaf curl virus) and ToCV (Tomato chlorosis virus). Their PCR amplicons were directly sequenced, and phylogenetic analyses were performed. Additionally, TYLCV infected plants were determined in the strain level. This study is the first record of Tomato chlorosis virus and Tomato yellow leaf curl virus causing infection in eggplant in Antalya province and characterized by yellowing type symptom in infected plant. | Eggplant (Solanum melongena) is an important source of food for people. Eggplant cultivations, located in the Mediterranean region province of Antalya, corresponds to 20% of the total eggplant production in Turkey. In Antalya province, yellowing type symptoms were observed in eggplant areas and it was found that these symptoms were not caused by fungal or bacterial cause. The yellowing symptoms characteristic for Solanaceae family, such as tomato and pepper, are also observed in the same family of eggplant. Total nucleic acids were obtained from infected eggplants were tested by RT-PCR/PCR with specific primers of TYLCV (Tomato yellow leaf curl virus) and ToCV (Tomato chlorosis virus). Their PCR amplicons were directly sequenced, and phylogenetic analyses were performed. Additionally, TYLCV infected plants were determined in the strain level. This study is the first record of Tomato chlorosis virus and Tomato yellow leaf curl virus causing infection in eggplant in Antalya province and characterized by yellowing type symptom in infected plant.
اظهر المزيد [+] اقل [-]Zinc oxide nanostructures as a control strategy of bacterial speck of tomato caused by Pseudomonas syringae in Egypt النص الكامل
2020
Elsharkawy, Mohsen | Derbalah, Aly | Hamza, Amany | El-Shaer, Abdelhamid
This study was conducted to evaluate the ability of zinc oxide nanoparticles (ZONPs) with unique properties to protect tomato against the bacterial speck pathogen, caused by Pseudomonas syringae pv. tomato DC3000 (Pst). Protection of tomato against bacterial speck using ZONPS was evaluated by its direct antibacterial activity and its ability for inducing resistance in tomato plants. The results revealed that ZONPs showed significant direct antibacterial activity against Pseudomonas syringae pv. tomato under laboratory conditions. Moreover, tomato plants treated with ZONPs showed a significant reduction in disease severity and bacterial proliferation relative to non-treated plants. Furthermore, tomato plants treated with ZONPs showed higher self-defense enzyme activity relative to untreated plants. The regulatory and defense genes, LePR-1a and Lipoxygenase (LOX), involved in the salicylic acid (SA) and (JA) signaling pathways, respectively, were highly expressed in tomato plants treated with ZONPs compared to untreated plants. Growth characters of tomato plants treated with ZONPs were significantly enhanced relative to untreated plants. The control of bacterial speck pathogen of tomato using ZONPs through its direct antibacterial and by developing of systemic resistance in treated tomatoes against the pathogen is considered the first report.
اظهر المزيد [+] اقل [-]Biological control of bacterial wilt of tomato caused by Ralstonia solanacearum using Pseudomonas species isolated from the rhizosphere of tomato plants النص الكامل
2020
Mohammed, Ayomide F. | Oloyede, Adejare R. | Odeseye, Adebola O.
Tomato bacterial wilt, caused by Ralstonia solanacearum, is one of the devastating soil-borne diseases of tomato plants in Nigeria. We investigated the potentiality of indigenous Pseudomonas species in controlling bacterial wilt of tomato. Seven Pseudomonas species were isolated and identified from the rhizosphere of tomato plants. The isolates were screened for enzyme production, and in vitro antimicrobial activity against pathogenic R. solanacearum using dual plate culture method. The biocontrol and growth-promoting efficacy of the Pseudomonas species were studied in the screenhouse using a completely randomised design. P. aeruginosa, P. syringae and P. fluorescens produced lipase, protease and α-amylase enzymes. All the Pseudomonas isolates except P. aureofaciens inhibited the growth of R. solanacearum. Since the tested species reduced the incidence of bacterial wilt and promoted the growth of the tested tomato genotypes, the indigenous Pseudomonas strain could be used to develop active biocontrol agents of tomato bacterial wilt in Nigeria.
اظهر المزيد [+] اقل [-]Amplifier Hosts May Play an Essential Role in Tomato Begomovirus Epidemics in Brazil النص الكامل
2020
Armando Bergamin Filho | Mônica A. Macedo | Gabriel M. Favara | Daiana Bampi | de Felipe F. Oliveira | Jorge A. M. Rezende
Current control of tomato golden mosaic disease, caused in Brazil predominantly by tomato severe rugose virus (ToSRV), is dependent on both, planting resistant/tolerant hybrids and intensive insecticide sprays (two to three per week) for controlling Bemisia tabaci, the vector of ToSRV. Resistant hybrids only confer moderate resistance to infection by ToSRV and some tolerance to the disease. Insecticide sprays, although widely used, have failed in most tomato production areas in Brazil, as they are unable to reduce primary spread, i.e., infection caused by the influx of viruliferous whiteflies coming from external sources of inoculum. Severe epidemics are recurrently observed in some tomato fields in several Brazilian regions, which prompted us to postulate the existence in the agroecosystem, in some places and time, of amplifier hosts that provide the necessary force of infection for epidemics to occur, even in the absence of secondary spread in the target crop. Amplifier hosts are ideally asymptomatic, occur in high density near the target crop, and support growth of both virus and vector. Soybean and common bean are potential amplifier hosts for begomovirus in tomato crops. Our results support the hypothesis that soybean plants may play an important role as an amplifier host of ToSRV for tomato crops in the field, although this does not seem to be a frequent phenomenon. Successful amplification will depend on several factors, including the soybean cultivar, the soybean stage of development at the moment of infection, the ToSRV isolate, and the perfect synchrony between the beginning of a soybean field and the end of a ToSRV-infected crop, and, later, between the senescence of the ToSRV-infected soybean plants and the new tomato crop. The concept of amplifier hosts has been widely used in ecology of zoonoses but, to our knowledge, has never been used in botanical epidemiology.
اظهر المزيد [+] اقل [-]Alteration of Bacterial Wilt Resistance in Tomato Plant by Microbiota Transplant النص الكامل
2020
Kihyuck Choi | Jinhee Choi | Pyeong An Lee | Nazish Roy | Nazish Roy | Raees Khan | Raees Khan | Hyoung Ju Lee | Hang Yeon Weon | Hyun Gi Kong | Seon-Woo Lee
Plant-associated microbiota plays an important role in plant disease resistance. Bacterial wilt resistance of tomato is a function of the quantitative trait of tomato plants; however, the mechanism underlying quantitative resistance is unexplored. In this study, we hypothesized that rhizosphere microbiota affects the resistance of tomato plants against soil-borne bacterial wilt caused by Ralstonia solanacearum. This hypothesis was tested using a tomato cultivar grown in a defined soil with various microbiota transplants. The bacterial wilt-resistant Hawaii 7996 tomato cultivar exhibited marked suppression and induction of disease severity after treatment with upland soil-derived and forest soil-derived microbiotas, respectively, whereas the transplants did not affect the disease severity in the susceptible tomato cultivar Moneymaker. The differential resistance of Hawaii 7996 to bacterial wilt was abolished by diluted or heat-killed microbiota transplantation. Microbial community analysis revealed the transplant-specific distinct community structure in the tomato rhizosphere and the significant enrichment of specific microbial operational taxonomic units (OTUs) in the rhizosphere of the upland soil microbiota-treated Hawaii 7996. These results suggest that the specific transplanted microbiota alters the bacterial wilt resistance in the resistant cultivar potentially through a priority effect.
اظهر المزيد [+] اقل [-]