ISSN 2736-1756
Advanced Journal of Microbiology Research Vol. 2015
Available online at http://internationalscholarsjournals.org/journal/ajmr
© 2015 International Scholars Journals
Full Length Research Paper
Current Rhizoctonia solani anastomosis groups in Egypt and their pathogenic relation to cotton seedlings
Maurice S. Mikhail1, Kamel K. Sabet1, Moawad R. Omar2, Amal A. Asran3 and Khaled K. Kasem1,4*
1Plant Pathology Department, Cairo University, Egypt.
2Plant Pathology Research Institute, Agricultural Research Centre, Giza, Egypt.
3Botany and Microbiology Department, College of Science, King Saud University, Saudi, P. O. Box 2455, Riyadh 1145, Saudi Arabia.
4Agricultural Research Centre, Hamah, General Commission for Scientific Agricultural Research, Syria.
Accepted 11 November, 2014
Abstract
Twenty eight isolates of Rhizoctonia solani were obtained from cotton seedlings and twenty three isolates from other hosts; eight from peanut, five from chickpea, two from each of flax, tomato and watermelon and one from each of potato, cantaloupe, pepper and lupine. Microscopic examination revealed that 17 isolates (33.33%) each belonged to AG-2- 2, 17 and AG-4 HG-I, while 7 isolates (13.73%) belonged to AG -4 HG-II and 10 isolates (19.61%) belonged to AG-5. Pathogenicity test on cotton cultivar Giza 86, under greenhouse conditions, showed that 19 isolates significantly induced pre- and post-emergence damping-off, while they significantly decreased survival, plant height and dry weight. However, the pathogenic isolates of AG-2-2 represented 19.61% of the total isolates as well as the highest percentage of the pathogenic isolates (52.63%). There were no significant differences between effects of different AGs on the cotton seedling variables. Cluster analysis suggested that grouping the isolates based on their virulence patterns was not related to their geographic origins, AG or host.
Key words: Rhizoctonia solani, anastomosis groups, cotton, pathogenicity.