Phenotypic and marker assisted evaluation for pathogenicity and aggressiveness of Romanian Fusarium isolates vs. wheat

Phenotypic and marker assisted evaluation for pathogenicity and aggressiveness of Romanian [Fusarium] isolates [vs.] wheat Pathogenicity and aggressiveness [vs.] wheat of 30 new [Fusarium] accessions, primarily [F. graminearum], obtained from random naturally infected grain samples of bread wheat, durum wheat and triticale collected across Romania, phenotypically and by molecular tools has been investigated. A large variation of this trait, expressed as reduction of coleoptiles length (% of control), in seedling stage, on average over three varieties, ranging from 2.1 to 30.9 % was registered. Point field inoculations at anthesis of 90 [Fusarium] isolate x wheat varieties combinations, revealed also the variability of several components of aggressiveness: [severity] (14.4-64.8%), [AUDPC] (104.9-527.1), and [FDK] 8.1-43.7%, respectively. Molecular techniques allowed identification of [Fusarium] species and the analysis of polymorphism within fungal isolates. Moreover, the presence of [TRI 5] gene involved in DON biosynthesis was detected in the majority of isolates. Similarity between records obtained in seedling and adult stage for the most aggressive of [Fusarium] isolates, suggests that phenotypic selection in conjunction with molecular tools could be a reliable method to select the appropriate pathogen strains for breeding of resistance.