PHYTOTOXICITY OF DEOXYNIVALENOL TO WHEAT TISSUE WITH REGARD TO IN-VITRO SELECTION FOR FUSARIUM HEAD BLIGHT RESISTANCE

Four types of wheat plant material i.e., seedlings, coleoptile segment s, anther-derived callus and anther-derived embryos, were tested at di fferent concentrations of deoxynivalenol (DON) and 3-aceiyldeoxynivale nol (3-ADON). DON inhibited growth of all types of plant material. See dling growth response to 4 x 10(-5)M 1 DON of a large set of genotypes did not differentiate between tolerant and sensitive genotypes accord ing to observed Fusarium Head Blight (FHB) resistance level in the fie ld. In general, coleoptile segments showed a growth reduction at 10(-5 ) M DON. A concentration of 10(-4) M DON appeared to be the optimum co ncentration to differentiate between haploid wheat calli for DON toler ance. However, growth analysis data of 40 callus clones did not show a ny correlation with the known FHB resistance levels of the original do nor genotypes and populations. Regeneration of the anther-derived embr yos in the embryo selection experiment was decreased 100-fold on DON-c ontaining medium. Averaged across the callus and embryo selection expe riments, green plant regeneration showed a decrease of approximately 2 0-foId on medium containing toxin.