الفهرس 
Pathogenicity, characterization and chemical control of fungal isolates causing early blight and gray mold diseases on tomato
CONTENTSOnly 14 pages are availabe for public view
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Abstract
The interaction between aggressiveness of Alternaria alternata, Alternaria solani and Botryts cinerea isolates and certain tomato hybrids. The isolates of A. alternata and A. solani can be divided into three categories; high aggressive (HA), aggressive (A) and less aggressive (LA) according to their infection severity in tomato seedlings. Isolates of B. cinerea were identified as aggressive isolates (A). Reactions of tomato hybrids to the chosen isolates clearly evidenced the significant differences between the isolates of each fungus. Hybrid F-1 TM10857 ranked as the most susceptible tomato hybrid, while Super hybrid Dutch was the least susceptible to the tested isolates. The least and most susceptible hybrids, Super hybrid Dutch and Hybrid F-1 TM10857 could be significantly separated not only by disease severity scores but also by quantification of peroxidase and polyphenol oxidase levels. characterization of A. alternata, A. solani and B. cinerea isolates. Radial growth test resultes significantly differed between the high and less aggressive isolates. The phytotoxicity of culture filtrate trials revealed that the crude culture filtrates and their dilutions of A. solani isolates were more toxic to seed germination and seedling growth of all tested crops than that of the other isolates of A. alternata and B. cinerea. The crude culture filtrates and their dilutions of the high aggressive isolates had more effect on plant seedling growth compared to less aggressive isolates. The enzyme activity (PG and CX) of the high aggressive isolates were more than that in the less aggressive isolates of tested fungi. Results showed that Bacillus megaterium bacterium was sensitive to mycotoxin (s) produced by tested isolates. The five phytotoxins and mycotoxins; Altenuene (ALT), Altertoxin (ATX), Alternariol (AOH), Alternariol methyl ether (AME) and Tenuazunic acid (TeA) were detected in the culture filtrate extracts of A. alternata and A. solani. A total of 14 metabolites were detected in the culture filtrate of the isolates of B. cinerea. The culture filtrate extracts of the high aggressive isolates of A. alternata, A. solani and B. cinerea had more phytotoxins than those of the less aggressive isolates