Evaluation of the local isolate Streptomyces kanamyceticus strain Tikrit-5 in control of gray rot disease on eggplant caused by Botrytis cinerea

Abstract

The study was carried to know the effect of local strain, Streptomyces kanamyceticus on the growth and production of three varieties of eggplant plants and its control gray rot disease. The results showed that the S. kanamyceticus with the fungicide Prado in the presence of the pathogenic fungus B. cinerea achieved the highest plant, shoot and root system of dry weight and leaf area in all eggplant cultivars compared with the lowest these parameters in the pathogenic fungus treatment. The results also showed the lowest infection severity with the pathogen B. cinerea was recorded in Barcelona cultivar treated with (S. kanamyceticus+ Prado) which reached to 21.23% compared with the highest infection severity of 80.06% in the Norita cultivar infected with the pathogenic fungus. S. kanamyceticus with the fungicide Prado in the presence of the pathogenic fungus Botrytis cinerea achieved the highest resistance induction agents such as chitinase, β–glucanase, peroxidase and polyphenol oxidase in all eggplant cultivars compared other treatments. The effect S. kanamyceticus was reflected by resistance induction, reducing the infection severity and improving the vegetative characteristics to a higher plant productivity. The highest fruit weight was recorded under the conditions of infection with the pathogenic fungus B. cinerea in Barcelona cultivar treated with S. kanamyceticus with the fungicide Prado reached to 588.82 gm compared with the lowest fruit weight of 301.41 gm in Norita cultivar in the treatment of pathogenic fungi only. In terms of fruit hardness, the treatment of S. kanamyceticus with the Prado in the presence of the pathogenic fungus B. cinerea achieved the highest fruit hardness reached 3.8 kg/cm2 in Barcelona cultivar compared with the lowest fruit hardness of 2.8 kg/cm2 in both cultivar Norita and Al-Nasr in the treatment of pathogenic fungus only.

Keywords

• Streptomyces kanamyceticus, Botrytis cinerea, eggplant cultivars