Totsky I. Influence of microgametophytic selection in F1 on the genetic structure of F2 populations and their resistance to abiotic stresses in sunflower (Helianthus annuus L.)

Object: genetic variability on gametophytic and sporophytic generations of sunflower (Helianthus annuus L.). Aim: establishment of influence of gametophytic selection in hybrids of the first generation on resistance to abiotic factors of environment and its genetic structure. Methods: crossbreed analysis, in vitro; field investigations, statistical analysis. Novelty: the influence of gametophytic selection in hybrids of the first generation on heat resistance, cold resistance and drought resistance of F2 populations, as well as on their genetic structure for «dichotomous venation», «dwarfness» and «virescent» marker traits was studied. Results: it was shown that pollen heating in F1 hybrids and its further using in pollination can increase not only the heat resistance of F2 populations, but also their drought resistance, and generally improve the adaptation ability of plants during growing under arid field conditions, accompanied by high temperature. Gametophytic selection for heat resistance was able to change the genetic structure of F2 populations modifying the ratio of plants with different height. It was found that the application of the solution of osmotically active substance (PEG 6000) on the stigmas of emasculated flowers before the pollination of F1 hybrids enhanced the drought resistance of F2 populations. Gametophytic selection was able to change the segregation ratios in F2 populations increasing the number of plants, which carried out the «dichotomous venation» and «dwarfness» marker traits. The simultaneous enhancing the cold resistance of F2 sporophytic populations, as well as increasing the number of plants, which have the «dichotomous venation» marker trait, in these populations and in their more cold resistance part may indicate that the genes, which determine this trait, are linked to the genes that responsible for cold resistance in sunflower. Application stage: the patent of Ukraine was founded. Application area: SIE of NAAS of Ukraine, MES of Ukraine7452