**2.1 Microgametophytic selection for drought tolerance in sunflower**

Despite the fact that the sunflower is a mesophyte, it is very demanding to the level of available soil and air humidity. That is why the yield and efficiency of its growth are limited by moisture provided to the plants. In sunflowers the yield losses may reach 50% because of drought [18]. It should be noted that drought is usually accompanied by temperature increase which invokes damage to the plants and decreases the yield as well. Therefore, enhancing the drought and heat tolerance of the plants is an important direction of modern sunflower breeding.
