Disease. Gummy stem blight. Causes leaf spot, stem canker, black leaf and fruit rot; common name refers to the characteristic gummy exudate. Didymella bryoniae (Auersw.) Rehm [anamorph Phoma cucurbitacearum (Fr.) Sacc.] is the causative agent of gummy stem blight (GSB), a disease affecting. Gummy stem blight of cucurbits produces a variety of symptoms which are referred to as leaf spot, stem canker, vine wilt and black fruit rot. Lesions on leaves.
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Ascochyta citrullina Chester C. After 3 days, leaves showing suspected early symptoms were collected in greenhouse.
Diagnostic Guide for Gummy Stem Blight and Black Rot on Cucurbits
When grown in vitro on agar, the fungus produces a white to olive-colored mycelium. The taxonomic treatment of the genus Didymella didgmella Corlett includes a useful summary of primary literature 6. Development and application of loop-mediated isothermal amplification for detection of the FY mutation of carbendazim-resistant isolates in Fusarium graminearum.
Received Jun 15; Accepted Aug Leaf spots are tan on cucumber; brown on melon, squash, and pumpkin; and dark brown on loofah and watermelon. First report of gummy stem blight, caused by Didymella bryoniaeon watermelon transplants in California.
The whole plant may wilt and then die. The small spots may be confused with anthracnose fruit rot on this bryoniad signs of the pathogen should be used to confirm the diagnosis.
In the United States, D. Use of loop-mediated isothermal amplification for detection of Ophiostoma clavatumthe primary blue stain fungus associated with Ips acuminatus.
Free moisture for at least one hour is necessary for infection and a high relative humidity for lesion expansion. Another useful characteristic is that a variable proportion of D. To start a fresh culture, one or two filter paper xidymella are placed onto agar and incubated as described previously.
Dark mycelium and fruiting bodies of Didymella bryoniae 3 days after culturing from a leaf spot on watermelon onto one-quarter-strength potato dextrose agar. The following list is arranged in an approximate order of susceptibility to both rbyoniae foliar blight and canker phases of gummy stem blight, starting with the species that are the most susceptible: The asexual spores cause secondary infections.
Studies on gummy stem blight disease of cucurbits in Trinidad. Optimal reaction time of LAMP.
If the cotyledons on inoculated plants are senescent or necrotic, the non-inoculated plants are examined as a reference to distinguish necrosis due to gummy stem blight from natural senescence. They usually are slightly larger than pseudothecia. From Wikipedia, the free encyclopedia. On both hosts, stems showed water-soaked lesions after rain, which dried up and cracked. Template DNA from D. The same results were obtained in all three replicates.
Didymella bryoniae – Bugwoodwiki
Resistant cultivars are currently not available. Our study does not involve human specimens or tissue samples, or vertebrate animals, embryos or tissues. American Phytopathological Society Press, St. Severities are averaged across the three seedlings subsamples per pot.
Seedlings should be inspected regularly for signs of infection as the disease is common at this stage. Regular benzimidazole fungicide applications can control this pathogen, didymlela certain D. After secondary spread, it may be possible to identify the seedling initially infected, because it will have bryoniwe and will be surrounded by symptomatic seedlings Fig.
Early and accurate detection of the causal agent D. Abstract Didymella bryoniae is a pathogenic fungus that causes gummy stem blight GSB in Cucurbitaceae crops e.