Tomato Rot Research Articles

Research Progress on the Occurrence and Control of Fusarium Crown and Root Rot of Tomato

Research Progress on the Occurrence and Control of Fusarium Crown and Root Rot of Tomato

Isolation and Identification of the Fungi Causing Tomato Fruit Rot Disease in the Vicinity of Tandojam, Sindh

Background: The post-harvest tomato fruit rot disease is common threat to the tomato fruit, causing huge economic loss as revealed by (GOP, 2018). The present study was conducted for isolatation and identification of causative agent of tomato fruit rot in order to formulate the proper management stretegies. Methods: Study was conducted in three phases. Phase one included collection of tomato fruit samples from vicinity of Tandojam. In phase two pathogens were isolated from the samples at laboratory, while in the phase three pathogens were identified using standard procedures. Result: The experimental results indicated Alternaria solani as the main cause of post-harvest tomato fruit rot. The symptoms observed were presence of brown to black rot lesions on tomato fruits with distinct rings ranging from small pin-heads to whole surface of fruit. A total of six different fungi viz., Alternaria alternata, Aspergillus niger, Alternaria solani, Geotrichum candidum, Fusarium oxysporum and Rhizopus stolonifer were found to be associated with post harvest tomato rot. Significantly higher infection was recorded for A. solani (53.667%) followed by A. niger (16.333%) and G. candidum (13.00%). The lowest infection percentage was observed for F. oxysporum (2.333%), followed by A. alternata (4.00%) and R. stolonifer (9.00%). A. solani produced aerial mycelium with yellowish to reddish diffusible pigments. A. niger cultures were typically black and colonies were initially whitish to yellow and later became brown to black in colour. G. candidum produced white and nonaerial colonies. F. oxysporum produced circular, aerial mycelium initially white, later changed to light pink. R. stolonifer produced whitish to grey fuzzy colonies.

Bio-Control Potentials of Trichoderma spp. Against Sclerotium rolfsii the Causative of Root and Crown Rot in Tomato, Common Bean and Cabbage

In the current study, evaluation the ability of three isolates of Sclerotium rolfsii isolated from tomato, bean and cabbage to infect their host plants and two non-host plants was carried out. Tomato plants were strongly affected with the three isolates of the pathogen followed by cabbage plants, whereas common bean plants were the least in this respect. Six species of Trichoderma were examined for their bio-control potentials against S. rolfsii the causative of root rot in tomato, common bean and cabbage. In vitro antagonistic test showed that T. koningii exhibited high inhibitory effect as the percentage of inhibition value was higher in case of S. rolfsii (tomato isolate) followed by T. harzianum with S. rolfsii (bean isolate) and S. rolfsii (cabbage isolate). Under greenhouse conditions; T. koningii, T. viride and T. harzianum showed the highest antagonistic effect against the three isolates of S. rolfsii in pots experiment. Microscopic examinations showed that most of Trichoderma spp. grew over mycelia of the tested pathogen with surrounded, coiling, lysis of hyphae and collapse of mycelium. T. koningii and T. viride exhibited the best performance regarding to the defense enzyme secretion; chitinase and β-glucanase followed by T. harzianum. Also, all the tested Trichoderma spp. produced Indole acetic acid (IAA) and Gibberellic acid (GA) as a plant growth promoting substances in variable values.

Genetic Diversity and Identification of Wilt and Root Rot Pathogens of Tomato in China.

Fungal wilt and root rot diseases affecting tomato have become prevalent in China in recent years and have caused considerable damage. In 2016 to 2018, symptoms of putative wilt and root rot diseases were observed in several locations in tomato cultivars with resistance to Fusarium oxysporum f. sp. lycopersici races 1 and 2. The objective of this study was to identify the causative agents of wilt and root rot of tomato in China and provide a basis for disease prevention and resistance breeding programs. Based on DNA sequence analyses of the internal transcribed spacer (ITS) region, 91 isolates from the roots of tomato plants showing symptoms of wilt and root rot were identified, including F. oxysporum (64 isolates), Fusarium solani (11 isolates), Fusarium proliferatum (2 isolates), Fusarium graminearum (2 isolates), Fusarium equiseti (1 isolate), Pythium aphanidermatum (6 isolates), Ascomycota sp. (2 isolates), and Plectosphaerella cucumerina (3 isolates). F. oxysporum accounted for 70.33% of the isolates obtained. In this case, using PCR-based methods for differentiation of F. oxysporum, we identified several formae speciales and races of F. oxysporum: 7 isolates were identified as F. oxysporum f. sp. lycopersici race 1, 2 isolates as F. oxysporum f. sp. lycopersici race 2, 35 isolates as F. oxysporum f. sp. lycopersici race 3, and 13 isolates as F. oxysporum f. sp. radicis-lycopersici. Pathogenicity tests revealed 55 isolates of tomato wilt and root rot pathogens to be virulent. This study demonstrated that F. oxysporum f. sp. lycopersici race 3 was the most widespread and highly virulent race among these tomato pathogens in China, followed by F. oxysporum f. sp. radicis-lycopersici. Therefore, the development of resistant varieties of tomato against F. oxysporum f. sp. lycopersici race 3 and F. oxysporum f. sp. radicis-lycopersici would aid efforts to develop effective disease management strategies.

Allelopathic effect of leaf extracts of Punica granatum and Spiraea prunifolia against post-harvest rot of tomato and brinjal

Antimycotic activities of different solvent extracts of Punica granatum L. and Spiraea prunifolia Siebold and Zucc. were carried out through agar well diffusion assay at three concentrations (25µl, 50µl and 75µl) against seven fungi causing rot diseases of tomato and brinjal. All the concentration of plant extracts showed antifungal activity against tested pathogenic fungi. Antimycotic activity increased with the increased concentrations of plant extracts. However, higher concentrations proved more effective than lower concentrations. It was revealed from the present study that the ethanolic extract of Punica granatum L. showed maximum antifungal activity against Rhizoctonia solani and Penicillium expansum and least inhibitory activity against Aspergillus niger. However, the aqueous extract of Punica granatum L. showed maximum antimycotic activity against Rhizoctonia solani and Alternaria alternata and least inhibitory effect against Penicillium expansum. It was further observed from the present study that the ethanolic extract of Spiraea prunifolia Siebold and Zucc. showed maximum antimycotic activity against Rhizoctonia solani and least inhibitory effect against Alternaria alternata. Whereas the aqueous extract of Spiraea prunifolia Siebold and Zucc showed maximum antifungal activity against Aspergillus niger and least inhibitory activity against Alternaria alternata.
 Keywords: Plant extracts, Concentration, Antimycotic effectiveness, tomato and brinjal, fungal rot pathogens, Inhibition zone.

Transcriptome Analysis Reveals the Effects of Chinese Chive (Allium tuberosum R.) Extract on Fusarium oxysporum f. sp. radicis-lycopersici Spore Germination.

Fusarium oxysporum f. sp. radicis-lycopersici (Forl) causes Fusarium crown and root rot of tomato, leading to severe yield losses. Chinese chive and the Chinese chive extract reportedly have antifungal effects. In this study, Chinese chive extract treatments inhibited Forl spore germination, with an EC50 of 0.40gml-1 in vitro. Furthermore, the mechanism underlying the fungicidal effects of the Chinese chive extract was analyzed by RNA sequencing. A total of 1252 differentially expressed genes (DEGs) were detected, of which 396 were upregulated and 856 were downregulated. The DEGs were related to starch and sucrose metabolism, amino sugar and nucleotide sugar metabolism, galactose metabolism, fatty acid metabolism, sphingolipid metabolism, glycerophospholipid metabolism, peroxisomes, ribosome biogenesis in eukaryotes, mismatch repair, and the phosphatidylinositol signaling system, implying these pathways contribute to the fungicidal activity of the Chinese chive extract. The qRT-PCR results verified the accuracy of the RNA sequencing data. Thus, the Chinese chive extract can inhibit Forl spore germination by affecting spore nutrient metabolism.

Evaluation of different plant extracts for effective management of fungal rot of tomato and brinjal in Kashmir Valley

The aim of present research was focused on the antifungal activities of Prunella vulgaris L and Paeonia suffruticosa Andrews via in vitro approach through agar well diffusion assay at three concentrations (25 uL, 50 uL and 75 uL) against fungi causing diseases in tomato and brinjal. All the concentration of plant extracts showed antimycotic activity against tested pathogenic fungi. Antimycotic activity increased with the increased concentrations of plant extracts. However, higher concentrations proved more effective than lower concentrations. It was revealed from the present study that the ethanolic and aqueous extracts of Prunella vulgaris L showed maximum antimycotic activity against Rhizoctonia solani and least inhibitory effect against Penicillium chrysogenum. It was further revealed from the present study that the ethanolic extract of Paeonia suffruticosa Andrews showed maximum antimycotic activity against Penicillium expansum and least activity against Mucor plumbeus. Whereas the aqueous extract of Paeonia suffruticosa Andrews showed maximum antimycotic activity against Rhizoctonia solani and Penicllium expansum and least inhibitory effect against Mucor plumbeus.

First Record of Melanospora chionea as a Possible Cause of Pink Root Rot Disease on Tomato Plants in Egypt

Tomato is one of the most important vegetable crops in the world. It is infected with several disease through the growth season, but new disease appeared as a new challenge to tomato productivity, causing pink root rot. Symptoms of pink root rot were observed on tomato (Lycopersicon esculentum Mill.) grown in Beni Sweif Governorate (Nasser, Sumosta, Beba and El-Wasta Counties) in summer 2013 as poor growth, chlorosis and then necrosis of the tip branches, by maturity. Typical symptoms on the infected root especially, epidermis were picked areas and both of cortex and vascular bundles were colored with pink along the infected tissues consistent with both those that were observed in the field. Based on morphological characteristics of the isolated fungus, disease symptoms and a pathogenicity test, Melanospora chionea was identified as the causal agent of pink root rot of tomato. Identification of this species was confirmed by sequencing of internal transcribed space (ITS region) of ribosomal RNA gene. M. chionea has not previously been reported on tomato. The host range of this disease was defined between numerous hosts belonging to Fabaceae, Malvaceae, Cucurbitaceae and Solanaceae. The aim of this work to determine and description of the disease and identification of the pathogen morphologicaly and genetically. More work is required to find appropriate methods for controlling this new disease.

Impact of phosphorus solubilizing microorganisms under different chemical sources of phosphorus and calcium on growth, yield and injury of blossom-end rot in tomato in high alkaline clay soil conditions

Impact of phosphorus solubilizing microorganisms under different chemical sources of phosphorus and calcium on growth, yield and injury of blossom-end rot in tomato in high alkaline clay soil conditions

EFFICIENCY OF TRICHODERMA VIRIDE AND BACILLUS SUBTILIS AS BIOCONTROL AGENTS AGAINST ROOT ROT CAUSED BY FUSARIUM SOLANI IN TOMATO

T omato (cv.Peto-86) is one of the important crops all over the world. In Egypt and many other countries it is often attacked by several pathogens causing root rot. Trichoderma and Bacillus species are widely the most feasible biocontrol microorganisms that suppress several pathogens. The efficiency of both antagonistic organisms was evaluated in vitro. as well as in vivo against root rot of tomato. The inoculation with T. viride and or B. subtilis of tomato plant suppressed F. salani as indexed by survival rate. Field experiments, ware carried out at Senowras Fayoum governorate during 2017 and 2018 seasons,. The obtained results showed that, the tested fungicide Topsin-M70 and the two biocontrol agents significantly reduced the incidence of root rot of tomato. The fungicide was the most efficient treatment in this regard compared with the two tested bioagents. Two bioagents treatments favored greater proliferation of rhizophere microflora and dehydrogenase activity in the rhizosphere. It is recommended to use these strains as a common biocontrol application in agriculture.

Antifungal Activity of Essential Oil and Hydrosol Extract of Ballota nigra L. and their Protective Effects Against the Black Rot of Tomatoes

Background: Bellota species are used to treat various diseases in traditional folk medicine. Objectives: This study aimed to chemically characterize the essential oils and the hydrosol extract and regional specificity of the major components of Ballota nigra essential oil and to evaluate their in vitro and in vivo antifungal activities. Methods: Essential oils were obtained by a Clevenger-type apparatus and analyzed by using Gas Chromatography (GC) and Gas Chromatography Mass Spectroscopy (GC/MS). The antifungal activities were tested to three phytopathogenic stains (Penicillium expansum, Aspergillus niger and Alternaria alternata). Results: Altogether, 38 compounds were identified in the essential oils, representing 92.1-96.8% of the total oil composition. Their main constituents were E-β-caryophyllene (4.8-24.6%), E-β-farnesene (3.3-22.9%), β-bisabolene (7.6-30.2%), α-humulene (2.1-13.3%) and geranyl linalool (1.1-8.2%). The statistical methods deployed confirmed that there is a relation between the essential oil compositions and the harvest locations. Hydrosol extract was constituted by seven components, represented principally by methyl eugenol (75.2%) and caryophyllene oxide (12.5%). The results of in vitro antifungal activity with essential oil and hydrosol extract have shown very interesting antifungal activities on Penicillium expansum and Alternaria alternata strains with percentage reductions up to 80%. Additionally, in in vivo assays, Ballota nigra essential oil and hydrosol extract significantly reduce decay in artificially inoculated tomato by Alternaria alternata. Conclusion: The essential oil and hydrosol extract can be used as a potential source of sustainable eco-friendly botanical fungicides to protect stored tomatoes from pathogens, saprophytic fungi causing bio-deterioration to a variety of food commodities.

Composts from green sources show an increased suppressiveness to soilborne plant pathogenic fungi: Relationships between physicochemical properties, disease suppression, and the microbiome

The need for studying tailored composts, as new feedstocks become available with time, increases the in-depth studies of suppressive composts derived from green sources and agro-wastes recycling. The composition, diversity and variability of microbiomes within a collection of 10 composts were investigated by amplicon sequencing and bioinformatics analyses. The observed differences in microbiome structure were related to the different compost origin. The multi-suppressive properties of composts from agricultural residues, agro-industrial co/by-products, and plant green-waste showed the most complex microbiome structure, which included either biocontrol agents associated with the control of Rhizoctonia damping-off in bean and Verticillium wilt in eggplant or microbial consortia for controlling Pythium damping-off in cucumber and zucchini and Phytophthora root rot in tomato and azalea. In contrast, the pathogen-specific property of composts from municipal solid waste and co-composted cow manure household waste showed a microbiome that overall included biocontrol agents against Fusarium wilt in tomato, melon and basil. The highest correlations between physicochemical properties, disease suppression, and the microbiome have allowed to make a helpful matrix to know how relationships among these variables of composts could be established and quantified for predicting their suppressive properties basing on the physicochemical properties and the microbiome.

Use of omic approaches for characterizing microbiota from suppressive compost to control soil-borne plant pathogens

Microbiomes composition, diversity, and variability into a collection of suppressive composts were investigated for effective biological control of soil-borne phytopathogens. Pyrosequencing resulted be a reliable and faster method for characterizing fungal and bacterial microbiomes into composts derived from a varied feedstock of different composition, origin and provenience. Differences in taxonomic structure assessed by bioinformatics analyses were related to feedstock origin. Green composts derived from agro-waste and agroindustrial co/byproducts provided the most varied microbiomes either related to suppression of Rhizoctonia damping-off in bean and Verticillium wilt in eggplant, either to control of Phytium damping-off in cucumber and Phytophthora root rot in tomato. On the other hand, composted municipal solid wastes and co-composted cow manure with household waste prevalently given a most specific microbiota related to suppression of Fusarium wilt in melon.

First report of crown and root rot of tomato caused by Fusarium equiseti in Algeria

Tomato (Solanum lycopersicum L.) is a socio-economically important crop in Algeria. From 2013 to 2016, surveys were performed on tomato plants showing symptoms of crown and root rot in North Algeria in Tlemcen, Oran, Mostaganem, Guelma and Sekikda Departments (disease incidence 62%). Fusarium isolates were recovered from surface-disinfected roots and stem collars of symptomatic plants, and cultivated on peptone pentachloronitrobenzene (PCNB) agar (Leslie and Summerell 2006). The aerial mycelium was white to brown with abundant macroconidia 5 to 7 septate (1.5 to 2.5 μm in width, and 75 to 100 μm in length), terminal and intercalary chlamydospores or in chains. No microconidia were observed. Nine monosporic cultures were identified morphologically as Fusarium equiseti (Corda) Saccardo (Jacobs et al. 2018). Identification of isolates was confirmed by DNA sequencing of the Translation Elongation Factor − 1 alpha (TEF1-α) gene, using EF1 and EF2 primers. Sequences of the isolates (GenBank Accession Nos. MG017430 to MG017438) against Fusarium MLST database showed similarity ranging from 98% to 100% with Fusarium incarnatum-equiseti species complex MLST type 5 (GQ505672 and GQ505597) (O'Donnell et al. 2015). Pathogenicity of each isolate was evaluated on ten 12-day-old seedlings of tomato cv. Monfavet 63.5 by cutting the roots 7 mm below the crown and dipping the plants for 5 min in 5 ml of 106 conidia ml−1 suspension in Minimal Liquid Medium (MLM). Ten non-inoculated control plants were also included in the experiment. The plants were incubated for four weeks in a greenhouse at room temperature between 20 and 25°C. The average infection percentage for all isolates was 55.2% of plants with crown and root rot symptoms. Control plants remained asymptomatic. F. equiseti was re-isolated only from inoculated plants, completing Koch's postulates. To our knowledge, this is the first report of F. equiseti as causal agent of crown and root rot of tomato in Algeria.

First Report of Corky Root Rot of Tomato Caused by Pyrenochaeta lycopersici in Africa

First Report of Corky Root Rot of Tomato Caused by <i>Pyrenochaeta lycopersici</i> in Africa

Influence of Calcium, Potassium and Watering Regimes on Blossom End Rot in Two Varieties of Tomato (Solanum lycopersicum) in Mandera County, Kenya

Blossom end rot (BER) is one of the physiological disorders of economic importance in tomato farming since it significantly reduces yield and thus affects profit margins. Most tomato disorders are due to mineral deficiencies and unbalanced nutrition. Improving the supply of specific nutrients and uniform soil moisture can reduce their occurrences. This study was conducted to evaluate the influence of watering regimes, Calcium (Ca) and Potassium (K) on blossom end rot occurrence in two tomato varieties in Maslah and Guul sites. The trials were laid out in a randomized complete block design (RCBD) in split-split plot arrangement with watering regimes (daily, thrice and twice a week) as main plots, tomato varieties (Riograde and Rionex) as sub plots, and 3 levels of Ca and K (0 Kg/ha, 25 Kg/ha, 50 kg/ha) as the sub-sub plots and replicated three times. Calcium treatments had the lowest score of blossom end rot compared to control. In Guul, the highest BER score (2.83) was observed under the control treatment while the lowest score (1.06) was recorded on the 50 kg/ha, Ca rate. Similar results were observed in Maslah with the control having the highest score of BER (3.22) while Ca 50 kg/ha scored lowest (1.11). No statistical differences were observed in the K treatments in the two study sites, however it was notable that lower rates of K reduced the blossom end rot incidences. Water stress led to increase in severity of the BER in the two study sites. In Guul, the highest score was in minimal watering regime (twice a week) of 2.36 score and lowest was at optimal watering regime (daily) of 1.08 score whereas in Maslah the highest blossom end rot score was in minimal watering regime (twice a week) of 3.19 and the lowest score of 1.19 on medium watering regime (Thrice a week).Therefore, optimal application of Ca, K, at 50 kg/ha with adequate and uniform soil moisture can improve management of blossom end rot in tomatoes thus raising farmer’s returns.

A Rapid Bioassay to Evaluate Efficacy of Hypovirulent Binucleate Rhizoctonia in Reducing Fusarium Crown and Root Rot of Tomato

Background: Fusarium Oxysporum f.sp. Radicis-Lycopersici (FORL) caused Fusarium Crown and Root Rot of tomato (FCRR), it’s a serious constraint on tomato production and contributing to yield losses. Aims/Method: Using a rapid bioassay, Hypovirulent Binucleate Rhizoctonia (HBNR) was tested for their ability to reduce Fusarium Crown and Root Rot (FCRR) of tomato, caused by Fusarium oxysporum f.sp. radicis lycopersici (FORL). Roots of tomato seedlings growing on 2% water agar in plastic boxes were inoculated with living or dead mycelial disks of HBNR. After 24 h, the pathogen was applied at 0, 3, 6, and 9 cm away from the position of the HBNR. Results: When living HBNR was used, the treatments provided significant protection to tomato seedlings from FCRR infection at all distances tested. Tomato plants pre-inoculated with living HBNR at different times (12 h and 24 h before inoculation with the pathogen) and challenged with FORL showed significant reduction of FCRR lesion development. A significant reduction was still observed even when HBNR was inoculated simultaneously with or 12 h after inoculation of a pathogen. Seedlings treated with dead HBNR and culture filtrates also showed significantly reduced FCRR lesion development. When living HBNR were enveloped by a polycarbonate membrane filter, a significant reduction of FCRR lesion development was still observed. Conclusion: In all experiments, reduction of FCRR lesion development in seedlings treated with HBNR tended to decrease with longer distance from the inoculation point of FORL and HBNR. We developed a simple, rapid, and miniaturized bioassay for evaluating the efficacy of HBNR against FORL. The bioassays require only 12 - 18 days, which is at least 12 days less than the soil system employed by previous researchers.

First Report of Root Rot of Tomato Caused by Phytophthora syringae in Pakistan

First Report of Root Rot of Tomato Caused by <i>Phytophthora syringae</i> in Pakistan

Biological control of Pythium damping-off and root-rot diseases of tomato using Trichoderma isolates employed alone or in combination

Tomato (Solanum lycopersicum L.), one of the most widely grown vegetables worldwide, is susceptible to damping-off and root rot caused by Pythium aphanidermatum (Edson) Fitzpatrick. In in vitro assays, five Trichoderma isolates, viz., Trichoderma harzianum (Th), T. asperellum (Ta), T. virens (Tvs1), T. virens (Tvs2) and T. virens (Tvs3) were compared for their ability to suppress P. aphanidermatum. The mycelial growth of the pathogen was inhibited in vitro after placing each Trichoderma species and isolates on the opposite sides of the same Petri dish. Trichoderma isolates were able not only to arrest the spread of the pathogen but also invade the surface of its colony and sporulate over the colony. Additionally, conidia of Trichoderma isolates were able to inhibit the germination of zoospores of P. aphanidermatum in vitro. Control of tomato damping-off and root rot diseases by soil treatment with the inoculum preparations of Trichoderma isolates employed either alone or in combination was attempted. In greenhouse experiment, the combined inoculation of five Trichoderma isolates suppressed damping-off induced by P. aphanidermatum and increased the survival of tomato plants by 74.5%. In field experiment, the possibility of reducing plant death resulting from root rot disease caused by P. aphanidermatum using Trichoderma isolates, employed either alone or in combination, was investigated. The combined inoculation of five Trichoderma isolates was the most effective treatment, decreasing root rot by 57.2% and increasing the survival of tomato plants by 87.5%. The tested Trichoderma isolates stimulated systemic defence responses in tomato plants grown in the field by activating defence enzymes including peroxidase, polyphenoloxidase and chitinase. Additionally, the chlorophyll contents in the leaves of treated tomato plants were markedly increased. Moreover, the combined inoculation of the five isolates yielded the highest records of growth parameters and fruit yield compared with individual inoculation. Therefore, it was concluded that the mixture containing Trichoderma species and isolates may be used to control damping-off and root rot of tomato caused by Pythium aphanidermatum.

Growth inhibitory activities of extracts from peels of five species of citrus fruit on bacterial isolates obtained from rotten tomato fruits.

This study was undertaken to verify the efficacies of phytochemical extracts of citrus fruit peels obtained from Citrus sinensis, Citrus reticulata, Citrus limonum, Citrus aurantifolia and Citrus vitis against isolates of tomato rot bacteria. Results of this study provide the much needed less hazardous, cheap and readily available means of controlling or managing bacterial diseases of postharvest tomato fruits to reduce the huge economic losses often incurred by tomato fruits dealers and farmers. Solvent extracts were characterized for presence of constituent active compounds, flavonoids, tannins, terpenes, cardiac glycosides, anthraquinones, saponins and alkaloids. Pseudomonas spp., Klebsiella spp. and Escherichia coli were isolated from rotten tomato fruits using McConkey, Blood and Peptone Sucrose agar media. Isolates were subjected to sensitivity test with 10%, 20%, 30% and 40% concentrations (volume by volume) of the different extracts, respectively. All the concentrations showed different degrees of growth inhibition on the test organisms. The study confirmed that phytochemical extracts from peels of citrus fruits are efficacious against tomato fruit rot bacteria and therefore have a good promise for sustainable control of bacterial rot disease of tomato fruits.