title: Identification and Characterization of Spontaneous Auxotrophic Mutants in Fusarium langsethiae.
abstract: Analysis of 49 strains ofFusarium langsethiaeoriginating from northern Europe (Russia, Finland, Sweden, UK, Norway, and Latvia) revealed the presence of spontaneous auxotrophic mutants that reflect natural intraspecific diversity. Our investigations detected that 49.0% ofF. langsethiaestrains were auxotrophic mutants for biotin, and 8.2% of the strains required thiamine as a growth factor. They failed to grow on vitamin-free media. For both prototrophic and auxotrophic strains, no growth defect was observed in rich organic media. Without essential vitamins, a significant reduction in the growth of the auxotrophic strains results in a decrease of the formation of T-2 toxin and diacetoxyscirpenol. In addition, all analysedF. langsethiaestrains were distinguished into two subgroups based on PCR product sizes. According to our results, 26 and 23 strains ofF. langsethiaebelong to subgroups I and II respectively. We determined that the deletion in the intergenic spacer (IGS) region of the rDNA ofF. langsethiaebelonging to subgroup II is linked with temperature sensitivity and causes a decrease in strain growth at 30 °C. Four thiamine auxotrophic strains were found in subgroup I, while 21 biotin auxotrophic strains were detected in subgroups II. To the best of our knowledge, the spontaneous mutations inF. langsethiaeobserved in the present work have not been previously reported.
authors.affiliation: All-Russian Institute of Plant Protection (VIZR), St.-Petersburg, Pushkin 196608, Russia. olgavrilova1@yandex.ru.
authors.forename: Olga
authors.initials: O
authors.lastname: Gavrilova
authors.affiliation: All-Russian Institute of Plant Protection (VIZR), St.-Petersburg, Pushkin 196608, Russia. orina-alex@yandex.ru.
authors.forename: Anna
authors.initials: A
authors.lastname: Skritnika
authors.affiliation: All-Russian Institute of Plant Protection (VIZR), St.-Petersburg, Pushkin 196608, Russia. t.gagkaeva@yahoo.com.
authors.forename: Tatiana
authors.initials: T
authors.lastname: Gagkaeva
keywords: auxotrophy; biotin; media; northern Europe; subgroups of F. langsethiae; temperature sensitivity; thiamine