First report of Fusarium wilt of watermelon in Vietnam

2016

and Fisheries make no representations and expressly disclaim all warranties (to the extent permitted by law) about the accuracy, completeness, or currency of information in this Final Report. Users of this Final Report should take independent action to confirm any information in this Final Report before relying on that information in any way. Reliance on any information provided by HIA Ltd is entirely at your own risk. HIA Ltd is not responsible for, and will not be liable for, any loss, damage, claim, expense, cost (including legal costs) or other liability arising in any way (including from HIA Ltd or any other person's negligence or otherwise) from your use or non-use of the Final Report or from reliance on information contained in the Final Report or that HIA Ltd provides to you by any other means. R&D projects: co-investment funding This project has been funded by Horticulture Innovation Australia Limited with co-investment from Monsanto Australia and Rijk Zwaan Australia Pty. Ltd and funds from the Australian Government.

Plant Breeding and Seed Science, 2011

Fusarium wilt of water melon caused by Fusarium solani in Hungary Water melon growers in Hungary have been recently reported a disease resembling that of Fusarium wilt developed on Fusarium resistant cultivars. Diseased samples from different regions of Hungary were collected in 2008 and 2009. The pathogen has been successfully isolated and identified as Fusarium solani. All of the isolates are host specific, but are very aggressive on water melon cultivars resistant to F. oxysporum f.sp. niveum. Severe infections occurred only in those fields where water melon has been grown continously for several years, but the pathogen is present in the soil of other fields as well.

Canadian Journal of Plant Pathology, 2019

Fusarium wilt of watermelon, caused by Fusarium oxysporum f. sp. niveum (FON), is a devastating soil-borne disease in watermelon production. Race 1 and race 2 of the pathogen are widely distributed in different watermelon producing regions. To investigate whether the root-knot nematodes break resistance of watermelon genotypes with resistance to FON race 1 and race 2, four greenhouse experiments were conducted on two watermelon cultivars 'Calhoun Gray' and 'Fascination' that are resistant to race 1, and an accession PI 296 341-FR that is resistant to race 2. The treatments included seedlings of 'Calhoun Gray' and 'Fascination' inoculated with Meloidogyne incognita (1000 J2/plant) or FON race 1 alone, nematodes 5 days before FON, FON 5 days before nematodes, nematodes and FON simultaneously, and non-inoculated control. PI 296 341-FR was inoculated with FON race 2, with or without M. incognita inoculation. The presence of M. incognita enhanced the susceptibility of all watermelon genotypes to Fusarium wilt. Co-inoculation with M. incognita led to an early development of wilt symptoms and increased disease severity. Galls were observed on roots of all nematode-inoculated plants, and sequential inoculation of FON followed by nematodes resulted in numerically lower galling indices compared with other inoculation methods. Whereas inoculation of the nematodes alone did not reduce plant growth, growth suppression was evident when seedlings were inoculated with both pathogens. The results indicated that M. incognita could enhance susceptibility of resistant watermelon genotypes to respective FON races, and host resistance alone is not sufficient for managing Fusarium wilt on watermelon in soils infested with root-knot nematodes.

Egyptian Journal of Phytopathology, 2018

usarium wilt in sweet potato was first observed in Middle Egypt governorates, i.e., Beni Sweif and Minia, between early April to September 2016. Disease symptoms started as a stunted growth, yellowing and wilting of the leaves, browning and discolouration of the xylem vessels. Koch's postulates were fulfilled and all Fusarium oxysporum isolates tested were able to infect sweet potato plants causing typical wilt symptoms. Prevalence, incidence and severity of sweet potato wilt (SPW) were varied with districts examined. Fungi belonging to five generae.g., Alternaria, Ceratocystis, Fusarium, Macrophomina and Rhizoctonia were found to be associated with wilted sweet potato plants. Fusarium spp recorded the highest frequency (80.6%) and Fusarium oxysporum showed 51.5%. frequency. Sweet potato genotypes were varied in their response to infection by Fusarium oxysporum isolate F1. Genotypes Menoufia 6 and Menoufia 2 reacted as resistant, while Local A and Line 26 were highly susceptible. Fusarium oxysporum f.sp. batatas isolate F1 was infective to convolvulaceous plants such as Cairo morning glory and field bindweed but was not pathogenic to non convolvulaceous plants such as alfalfa, carrot, cotton, potato, sugar beet, sugarcane, turnip and wheat. Chlorophyll degradation was ralated to sweet potato genotypes reaction towards Fusarium oxysporum f.sp. batatas infection. Least degradation values were found in resistant genotypes and vice versa exhibited by susceptible genotypes. In contrast, phenols were enhanced when Fusarium oxysporum f.sp. batatas infected the resistant genotypes and decreased in the susceptible genotypes compared with uninfected.

New Biotechnology, 2010

Phytoparasitica, 2006

Tropical Life Sciences Research, 2020

Fusarium wilt disease is one of the most problematic and destructive disease in cucumber production. The causative agents are Fusarium oxysporum and F. solani. These pathogens are soil borne and transmitted through infested soil and water. A field survey was conducted to study the disease prevalence in the major growing areas of cucumber in Peninsular Malaysia. Field study revealed that the disease was highly prevalence in the field with the disease incidence was in the range of 10%–60%. The morphological properties of F. oxysporum are microconidia (3.8–15.7 μm × 2.9–4.9 μm), macroconidia (14.8–38.5 μm × 2.4–5.7 μm) and number of septate was 1–4. While for F. solani are microconidia (3.39–14.63 μm × 2.36–4.44 μm), macroconidia (7.22–50.46 μm × 2.43–6.14 μm) and number of septate was 1–5. Based on molecular identification had confirmed that the disease is caused by F. oxysporum and F. solani with similarity index of 99%–100% based on internal transcribed spacer (ITS) gene sequences. ...

Jurnal Biologi Udayana

This research was aimed to isolate and identify microbes which antagonistic against Fusarium oxysporum, the causative agent of vascular wilt in watermelon plants. The antagonistic microbes were isolated from soil samples collected from rhizosphere of watermelon farm located at west Sanur village, South Denpasar, Bali. Isolation of fungi and bacteria were conducted on potato dextrose agar medium (PDA) and nutrient agar medium (NA), respectively. Fungal isolates were then observed under light microscope for its morphological characteristics before identification using a reference book. Bacterial isolates were characterized using various tests, such as gram stain reaction, existence of endospores, catalase reaction, and ability to ferment various sugars. Their characteristics were then compared with those described in a reference book. Two fungal species (Trichoderma harzianum and Trichoderma viride) and two bacterial antagonists (Pseudomonas sp. and Bacillus sp.) were found to ha...

A severe vascular pomegranate wilt (Punica granatum L.) has recently been discovered and reported for the first time in Upper Egypt. Diseased samples were obtained from an infected farm in El-Badari city, Assiut Governorate, Egypt, and the pathogen was isolated on potato dextrose agar at 25 °C. Phenotypic features and DNA sequencing of the pathogen's internal transcribed spacer region showed that the fungus was Fusarium oxysporum. The pathogenicity study conducted with 2-year-old plants resulted in 80% infection. F. oxysporum re-isolated from all the inoculated pomegranate trees exhibited the same morphological characters as those observed among the isolates.

Phytoparasitica, 2008

MycoKeys

Fusarium is one of the most important fungal genera of plant pathogens that affect the cultivation of a wide range of crops. Agricultural losses caused by Fusarium oxysporum f. sp. cubense (Foc) directly affect the income, subsistence, and nourishment of thousands of farmers worldwide. For Viet Nam, predictions on the impact of Foc for the future are dramatic, with an estimated loss in the banana production area of 8% within the next five years and up to 71% within the next 25 years. In the current study, we applied a combined morphological-molecular approach to assess the taxonomic identity and phylogenetic position of the different Foc isolates collected in northern Viet Nam. In addition, we aimed to estimate the proportion of the different Fusarium races infecting bananas in northern Viet Nam. The morphology of the isolates was investigated by growing the collected Fusarium isolates on four distinct nutritious media (PDA, SNA, CLA, and OMA). Molecular phylogenetic relationships w...

Plant Disease, 2018

Panama disease of banana, caused by Fusarium oxysporum f. sp. cubense (Foc), poses a great risk to global banana production. Tropical race 4 (TR4) of Foc, which affects Cavendish bananas as well as many other banana cultivars (4; see eXtra link), was confirmed for the first time outside Southeast Asia in Jordan in 2013 (2). In Pakistan, bananas are produced in the Sindh and Balochistan provinces (91%-31,000 ha-and 9% of the country's production, respectively). Symptoms of Fusarium wilt, including wilting of leaves and vascular discoloration in rhizomes and pseudostems, were first observed in 2012 in a 2 ha Cavendish plantation in Baoo Pooran (ca. 24°N, 68°E), Sindh province. By January 2014, approximately 121 ha were affected. In Lebanon, bananas are produced for local consumption and regional export, especially to Syria. Yellowing of leaves and internal vascular discoloration in the pseudostems was first observed in Cavendish plants in October 2013 in the Mansouri and Berghliyeh regions. Thus far, 1 ha has been affected. Infected pseudostem tissue samples from Pakistan and Lebanon were processed for Foc isolation and characterization as described by García-Bastidas et al. (2). White colonies developed from the surface sterilized (70% ethanol) tissue on Komada's medium (3) and nine single microconidia isolates were generated, four from the Pakistan sample and five from the Lebanon samples and transferred to quarter-strength PDA. All isolates phenotypically resembled F. oxysporum (3) and were diagnosed as vegetative compatibility group (VCG) 01213 (Fig. 1), which was confirmed by PCR (Fig. 2), thereby corroborating that VCG01213 only represents TR4 strains (4). Subsequently, one of the isolates from Pakistan (Pak1.1A) and one isolate each from Mansouri (Leb1.1A) and Berghliyeh (Leb1.2C) in Lebanon were analyzed for pathogenicity. Inoculum production and inoculation were according to Dita et al. (1) by dipping (30 min, 10 6 spores/ml) root-wounded 10 week-old Cavendish cv. Grand Naine plants, which were then placed in sand in 3L pots under 28 o C, 70% relative humidity and a 16h diurnal light periods for 6 weeks. Sets of three plants were each treated with either Pak1.1A, Leb1.1A, Leb1.2C or TR4 (reference isolate II-5, which was diagnosed as TR4 by PCR and pathogenicity analyses, see (1)). Control sets were each treated with either Foc Race1 (Cruz das Almas, Brazil, see (1)), or water. After 4 weeks, all plants inoculated with the isolates from Pakistan, Lebanon and TR4 (II-5) produced typical symptoms of Fusarium wilt. After 6 weeks, internal symptoms were recorded (Fig. 2) and tissue was collected from all plants and plated on Komada's medium. TR4 was confirmed by PCR from isolates that were recovered from all symptomatic plants. No isolates were recovered from plants infected with Race 1 or the water controls, all of which remained asymptomatic. Thus, we confirm the presence of TR4 in Pakistan and Lebanon and its continued expansion and distribution in Western Asia. Although comparatively limited production areas have been affected to date, increasing damage will undoubtedly occur in these countries in the near future.

PLOS ONE

Fusarium wilt of watermelon, caused by Fusarium oxysporum f. sp. niveum (FON), occurs worldwide and is responsible for substantial yield losses in watermelon-producing areas of the southeastern United States. Management of this disease largely relies on the use of integrated pest management (i.e., fungicides, resistant cultivars, crop rotation, etc.). Knowledge about race structure and genetic diversity of FON in the southeastern US is limited. To determine genetic diversity of the pathogen, FON isolates were collected from symptomatic watermelon plants in commercial fields in Georgia and Florida, USA, and identified based on morphological characteristics and PCR analysis using FON-specific primers. Discriminant analysis of principal components (DAPC) of 99 isolates genotyped with 15 simple sequence repeat (SSR) markers grouped the isolates in eight distinct clusters with two prominent clusters (clusters 1 and 8). Cluster 1 consisted of a total of 14 isolates, out of which 85.7% of the isolates were collected in Florida. However, most of the isolates (92.4%) in cluster 8 were collected in Georgia. Both DAPC and pairwise population differentiation analysis (Ф PT) revealed that the genetic groups were closely associated with geographical locations of pathogen collection. Three races of FON (races 0, 2 and 3) were identified in the phenotypic analysis; with race 3 identified for the first time in Georgia. Overall, 5.1%, 38.9% and 55.9% of the isolates were identified as race 0, race 2 and race 3, respectively. The majority of the isolates in cluster 1 and cluster 8 belonged to either race 2 (35.6%) or race 3 (45.8%). Additionally, no relationship between genetic cluster assignment and races of the isolates was observed. The information obtained on genotypic and phenotypic diversity of FON in the southeastern US will help in development of effective disease management programs to combat Fusarium wilt.

2020

Degree: MSC IN LIFE SCIENCES Exact wording of the title of the dissertation as appearing on the copies submitted for examination: CHARACTERISATION OF FUSARIUM OXYSPORUM SPECIES COMPLEX ASSOCIATED WITH FUSARIUM WILT OF SWEET POTATO IN SOUTH AFRICA I declare that the above dissertation is my own work and that all the sources that I have used or quoted have been indicated and acknowledged by means of complete references.

The Pharma Innovation, 2021

Tomato occupies a major position in the family Solanaceae and it is the highly consumable crop all over the world. Among the various diseases affecting tomato, wilt incited by Fusarium oxysporum f. sp. Lycopersici is the one of the economically important disease which causes yield loss upto 50%. In the present study, survey was undertaken in Madurai districts of Tamil Nadu for the collection of Fusarium isolates. The Fusarium wilt disease incidence was noticed with the range of 23.3-42.2 per cent in various tomato cultivars. Ten isolates of Fusarium were isolated from symptomatic tissues and maintained in pure culture. All the 10 isolates produced dull to deep white colour colony with a diameter ranged from 80-90 mm in PDA medium. The pathogenicity test using the cultivar PKM-1was carried out and by sand maize agar medium revealed that, the isolate FO (Maa-5) was more virulent followed by FO (Mel-7) and FO (Kar-2) which was found to be least virulent. The morphological and pathogenic variability among the Fusarium isolates were observed within the close proximity.