| Pak. J. Bot., 34(4): 433-440, 2002 | Back to Contents | ||||
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Updated: 24-05-12 | ||||
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Genetic variation among Fusarium
oxysporum f.sp. ciceris isolates in Pakistan as determined by biological
pathotyping and vegetative compatibility Iftikhar A. Khan, Abdul Jabbar and S. Sarwar Alam Abstract: Fusarium oxysporum f.sp. ciceris isolates 2005, 2007, 2012, 9718 and 9910 were highly virulent and produced more than 50% mortality in chickpea varieties. Of these, the isolate 9718 was found to be most aggressive. The isolates 2011, 9925, 7952, 8012, 7989 and 7802 were virulent whereas isolates 2001, 2002, 2003, 2004, 2008, 2009, 2014, 9917 and FOI were less virulent and caused less than 25% mortality. Complementation test of various nit mutants of local isolates with each other and with international isolates revealed that the virulent isolates viz., 2005, 2007, 2011, 2012, 9718 and 9910 were compatible with the wilt causing isolates 8012 (race 5 from Spain) and 7989 (race 1A from India) and belonged to vegetative compatibility group 0280. The yellowing causing isolates 7952 and 7802 (race 5 from Spain) were not compatible with either wilt causing international isolates 8012 and 7989 or with local virulent isolates, so these belong to another VCG. The less virulent /non-pathogenic isolates 2002, 2003, 2004, 2008, 2009, 2014 and FOI were not compatible with each other and with virulent isolates. No correlation was found between races and vegetative compatibility groups however a relationship occurred between symptoms produced by the isolates and VCG, because all the wilt causing isolates belonged to same VCG 0280. Our results suggest that two distinct VCG's are prevalent in the world and only wilt causing VCG is prevalent in Pakistan. |
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