Tropical Plant Pathology (2009) 34, 51-55

Litervaldo P. Machado, Sami J. Michereff, Beatriz A.S. Falleiro, Marcelo G. Oliveira, Wirton M. Coutinho, Camilo L. Morello and Nelson D. Suassuna (2009)
Um método simples e rápido de seleção para resistência à murcha-de-fusário em genótipos de algodoeiro
[A simple and fast method to screen cotton genotypes for fusarium wilt resistance]
Tropical Plant Pathology 34 (1), 51-55
Abstract: This study describes a new method to screen cotton genotypes for wilt resistance caused by Fusarium oxysporum f. sp. vasinfectum. Cotton genotypes were sown in germination trays (25 mL each cell) with sterilized vermiculite. On the fifth and the seventh days after germination, each seedling was inoculated with a suspension adjusted to 5 x 10⁵ spores/mL. Resistance was evaluated using 1) the area under disease progress curve (AUDPC), for 15 days starting on the tenth day after the first inoculation (DAI); 2) disease severity on the 25^th DAI; 3) percent of seedlings showing vascular system browning and 4) percent of seedlings with pathogen in the vascular system on the 25^th DAI. No significant differences were found among genotypes Clevewilt 6, Auburn 56-24, Bayou SM-1, Coker 312, Stoneville 132, IAC RM2 and BJ 1302 for AUDPC and disease severity. When considering disease severity, genotypes Auburn 56-24, coker 312 and Bayou SM-1 were more resistant than Deltapine 45A, whereas for AUDPC only Coker 312 and Bayou SM-1 were more resistant than Deltapine 45A. Coker 312 was more resistant than Acala 44 only for disease severity. There was a significant correlation between AUDPC and disease severity, however, due to its ease, the latter index was found to be the best to screen cotton genotypes for fusarium wilt resistance.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
(original language: Portuguese)
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Database assignments for author(s): Sami J. Michereff

Research topic(s) for pests/diseases/weeds:
resistance/tolerance/defence of host

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Fusarium gossypinum	Cotton (Gossypium)