Results are presented from phytopathological investigations carried out on the progenies of several generations with the aim to find out their resistance to grey (Phomopsos helianthi) and black (phoma macdonaldi) spots on sunflower. The investigations were carried out in the infection field of Dobrudzha Agricultural Institute during 2004 - 2008. Infected plant residues (streams) with symptoms of the diseases caused by the two pathogens were annually introduced in the testing plots. The stems were collected the previous year and left in the field during the winter. They were spread in zig-zag between the rows after emergence of the sunflower plants. As a result from selfing and purposeful selection several lines were developed; they combined high resistance with valuable economic traits. The obtained materials possess resistance genes and can therefore be either successfully used as donor for resistance or to develop new hybrid combinations.
Phytopathological characterization of sunflower lines for resistance to the cause agents of grey (Phomopsis helianthi) black (Phoma macdonaldi) spots and broun spots (Alternaria sp.)