Selection evaluation of new self­pollinated sunflower (Helianthus annuus L.) lines with resistance to sulfonylurea herbicides and downy mildew [Plasmopara halstedii (Farl.) Berl. et. de Tony]

Abstract

Purpose. To determine the breeding value of a new sunflower source with complex resistance to sulfonylurea herbicides and downy mildew. Methods. In the research process, field (hybridization, line testing, individual selection, line evaluation), visual (phenological observations), laboratory (immunological evaluation of resistance to DM), vegetation (evaluation of resistance to herbicides) and mathematical and statistical (processing of experimental data and determination of reliability of research results) methods were used. Results. During 2020–2023, new self­pollinated sunflower lines were studied in the cross­pollination and bree­ding department of the Plant Breeding & Genetics Institute – National Center of Seeds and Cultivar Investigation (PBGI – NCSCI). Based on the results of the work, 33 self­pollinated sunflower lines with complex resistance to sulfonylurea herbicides and downy mildew (DM) were created and evaluated. The lines were created using domestic breeding populations that were able to reach their full genetic potential in various conditions. These populations were adapted to cultivation in the southern steppe of Ukraine and were resistant to a complex of diseases and pests. Additionally, they had increased seed yield and plasticity. The new source material obtained is constant, stably productive lines used in the subsequent breeding programme. According to the results of the trials, almost all the hybrids obtained (F1) showed a yield of more than 1.0 t/ha. Lines with the highest level of combining ability in terms of yield (heterozygous hybrid progeny with increased viability for the main economic and valuable traits) will be selected for further research and will be involved in the creation of new hybrids resistant to sulfonylurea herbicides and DM. Conclusions. Research showed that traits such as sulfonylurea herbicide resistance and downy mildew resistance can be combined in one line. Herbicide resistance in sunflowers is easy to control in the field, while downy mildew resistance needs to be controlled in the laboratory.