Fusarium head blight in Argentina
1997
De Galich, M.T.V. (Marcos Juarez Agricultural Experiment Station, Cordoba (Argentina))
During the last 50 years, 16 fusarium head blight (FHB) epidemics, mainly caused by Fusarium graminearum, have occurred in the central-north area of Argentina. Other known Fusarium species less pathogenic on wheat include F. equiseti, F. semitectum, F. poae, F. acuminatum, F. moniliforme, F. m. var. subglutinans, F. m. var. anthophilum, F. Oxysporum, and F. solani. Studies on the toxigenic capacity of isolated F. graminearum strains noted the abundance of deoxynivalenol (DON) producers, with a lesser proportion of nivalenol (NIV) producers. Some strains produced both DON and NIV. Zearalone (ZEA) was identified in more than half of the strains, and no relation was found between DON and NIV groups with regard to ZEA production. An integrated approach should be adopted to decrease FHB damage, taking into account the epidemiological characteristics of the pathogen, scarce genetic resistance in the host, and the strong environmental influence on FHB. Studies carried out at Marcos Juarez agricultural Experiment Station aim to develop germplasm with higher FHB resistance levels and good agronomic traits to be used as parents in the bread wheat breeding program. The methodology includes: (1) identification of resistance sources under semicontrolled conditions and artificial inoculation, and (2) incorporation of resistance into genotypes that have good agronomic traits. Despite some references suggesting that resistance is controlled by a few major genes / most indicate poligenic inheritance with additive effects and components of dominance. It may therefore be considered possible to obtain higher levels of resistance through a process of crossing and selection in order to accumulate resistance genes.
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