REACTION OF THE LITHUANIAN ALFALFA BREEDING POPULATIONS TO PHOMA MEDICAGINIS UNDER COOL TEMPERATE CLIMATE CONDITIONS

The alfalfa Phoma medicaginis resistance was evaluated on 100 accessions with different development date. Weather conditions favoured high disease pressure and differentiation of tested accessions was not clear in 2011. Accessions were compared by maximal disease severity (DS) and area under disease progress curve (AUDPC). DS ranged from 10 to 60% and AUDPC value ranged 119-727 in 2009. DS and AUDPC values were higher in 2010 and 2011, DS ranged 40-65 and 66-68% and AUDPC ranged 2263-2928 and 2853-3006. Development date of accessions showed low impact on resistance. The correlations between DS and AUDPC results of accessions across years highly varied (r=-0.189 - 0.828**) due to low differentiation of accessions resistance. Selection of alfalfa material promising by Phoma medicaginis resistance should be done under conditions moderately favourable for development of this disease.