There are some reports that low doses of γ-irradiation could induce antioxidant activities in plant material, including soybean. Irradiation, required for the inactivation of some pathogens and induction of mutations, may have adverse effects on sensorial, nutritional and antioxidant qualities. The effects of different γ-irradiation doses (100-200 Gy) on antioxidant properties of soybean seeds was investigated. In this study, we report the results obtained by analysis of antioxidant enzyme activities, reduced glutathione, malonyldialdehyde (MDA) and hydroxyl (HO˙) radical quantities, soluble protein content, and total antioxidant activity in irradiated soybean seeds. Antioxidant enzyme activities were affected due to high irradiation intensity. Significant changes of total antioxidant activity and MDA and HO˙quantities were observed only under the highest irradiation dose, with a 15.7% reduction in total antioxidant activity, MDA quantity increase of 21.6%, and HO˙ radical quantity increase of 79.3% compared to the non-irradiated control. The total soluble protein content increased slightly.

Three sunflower inbred lines differing in resistance to Sclerotinia were grown on nutritive medium supplemented with different concentrations of oxalic acid. After two weeks of culture, plant height, fresh and dry weight of above-ground part, length of first pair of leaves, root length, and fresh and dry weight of root were measured. Data obtained were analysed using ANOVA and LSD test. Out of the tested parameters, plant height and root length were found to be the most reliable indicators of plant resistance/susceptibility to Sclerotinia. Based on the data obtained, oxalic acid concentrations of 4 mM, 3 mM and 2 mM were chosen for further work in which test would be done on a larger number of genotypes.

Five populations of each H. molis, H. maximiliani, H. rigidus and H. tuberosus were screened for resistance to stem form of Sclerotinia. On the basis of the results obtained by screening, nine crosses of resistant populations with either other wild species populations or with cultivated sunflower were made. As in some crosses a small quantity of seed was produced and the seeds germinated poorly, modified tissue culture methods were used to enhance germination and produce clones of interesting plants. These methods were found to be efficient both for seed germination and plant production and multiplication