The total content of watersoluble antioxidants in the rhizomes of garden iris varies depending on the hardiness of the variety. Domestic varieties have better winter hardiness than varieties of foreign breeding. The amount of antioxidant content in the rhizomes at the winter-hardy varieties of iris garden after wintering is significantly reduced. The direct positive correlation between of the average degree of the total content of antioxidants in the rhizomes of iris garden and winter hardiness was revealed. The correlation coefficient is r=0,66. Therefore, the total content of water-soluble antioxidants in the rhizomes of iris garden can be apply as a potential marker of long hardiness source material.
