Biological Control of Cucumber Mosaic Virus by Certain Local Streptomyces Isolates: Inhibitory Effects of Selected Five Egyptian Isolates
An antiviral producing Streptomyces species were isolated from soil rhizosphere in Zagazig province of Egypt. In order to identify the Streptomyces strains, morphological, physiological, biochemical and antagonism tests were performed. The Egyptian isolates of Streptomyces were found to be a species of calvus, canarius, vinaceusdrappus, nogalater and viridosporus. The Streptomyces spp. were grown in glycerol asparagine broth medium and the culture supernatants obtained were 0.45-μm filter. These isolates were tested in two experiments for their ability to control a Cucumber Mosaic Virus (CMV). In the 1st experiment, one half of leaves of Chenopodium amaranticolor were treated with Culture Filtrate (CF) followed by CMV inoculation on both halves. In the 2nd experiment, the first pair of Cucumis sativus leaves were treated CF with CMV mechanically inoculated onto one leaf, the other non-treated leaf was CMV inoculated after 7 days of treatment. In 1st experiment, CF treatment was able to considerably reduced the number of local lesion and in 2nd experiment, plants treated with CF showed variable visible viral symptoms compared with the broth media treated control 15 days post inoculation and remained symptom less throughout the study period. Such five Streptomyces species identified were able to produce an antiviral component in the culture filtrate, non phytotoxic and effective in local as well as systematically control of CMV infection.
Cited References Fulltext