A response of geographical isolates of Phoma macdonaldii Boerema different on aggressiveness degree on changes of temperature and illumination in controlled environments

The purpose of the work was to compare geographical isolates of Phoma macdonaldii Boerema, different on aggressiveness degree, their capability to form organs for pycnidium propagation and intensity of radial growth of colonies at the different temperatures and illuminations in the controlled environments. As a result of conducted researches we determined an optimal temperature (25 оС) for the intensive radial growth of colonies differed Ph. macdonaldii isolates aggressiveness from the various regions of the Russian Federation, both in the light and in dark. Large amount of pycnidia (substantial at 5% significance level) on the studied isolates of a fungus were formed at twenty-four-hour illumination, independently on their aggressiveness. Rapid of a radial growth of Ph. macdonaldii colonies correlated with their aggressiveness at their cultivation at twenty-four-hour illumination and 30 оС temperature, and possibly it can be used as a criterion for selection of the most aggressive fungus forms. However, it should be proved on the more amounts of isolates.