**2.2 Microgametophytic selection for drought tolerance in oil flax**

Under conditions of prolonged exposure to high temperatures and insufficient moisture supply, typical for the south of Ukraine, oil flax often reduces its potential productivity. The above makes the development of drought-resistant varieties of this crop urgent. The significant differences between flax genotypes insensitivity to elevated temperatures at the stage of the mature pollen grain and the discovered positive relationship between resistance to high temperatures of microgametophytes and drought tolerance of sporophytes, which we established, provide an opportunity for selection of drought-resistant genotypes at the microgametophytic level [10, 25].

Intervarietal *F*1 hybrids K7487 × K7734 and K7734 × K7487 were used as the starting material, the parental lines of which significantly differed in their resistance to drought. Pollen was collected in the morning hours. Using a dissecting needle, the pollen from the anthers was shaken out onto a glass slide and after that, it was evenly distributed over the surface of the glass in a monolayer. Then glasses with pollen were *Microgametophytic Selection as a Way to Improve Drought Tolerance in Cultivated Plants DOI: http://dx.doi.org/10.5772/intechopen.102735*

