Donor-acceptor relations influence on the modern spring wheat varieties photosynthetic system activity

The article presents the field experiments’ many years results on the leaves photosynthetic activity manifestation varietal aspects study in spring wheat plants. It was shown on 25 modern cultivars that the leaf photosynthesis intensity significantly depends on the donor-acceptor relationships in nature, which are determined by the plants’ hereditary characteristics, the growth phase, location and vegetation conditions. The most active CO 2 molecules assimilation from the air is the plants flag leaf, on which the main fruit load falls. During the caryopsis formation period, in photosynthesis intensity terms, it exceeded the pre-flag leaf by an average of 1.5 times, and the lower one by 2.7 times. In special model field experiments, it was found that its removal from plants leads to an increase in the pre-flag leaf photosynthesis intensity by an average of 35.4%, and the third from the top - by 28.0%. When the flag leaf remains alone, and the rest are removed, its CO 2 assimilation intensity increases only by 5.6%. It was concluded that the spring wheat genetic resources are characterized by a plant leaves photosynthesis intensity sufficiently wide polymorphism to effectively select forms with a photosynthesis high activity and purposefully use inbreeding. Work in this direction may well be successful since the leaves photosynthesis intensity in culture plants is high hereditary conditioning.