Impact of stomatal traits variation on grain yield in winter wheat

E. Ivandi, H. Hõrak, E. Merilo, R. Koppel
Institute of Technology, Faculty of Science and Technology, University of Tartu, Nooruse 1, 50411, Tartu, Estonia

Stomata are small pores that control gaseous diffusion and water loss of plant leaves. Rising air temperatures and an increase in droughts will affect stomatal traits and cause stress in plants. Wheat (Triticum aestivum) is the most cultivated food culture in the world. Therefore, it is important to understand how wheat stomata behave in stressful situations. So far it has been found that in wheat the adaxial surface has more stomata than the abaxial surface, but less is known about the relationship between stomatal ratio and grain yield and how environmental conditions affect wheat stomatal anatomy and physiology. Field trials were carried out with 25 varieties of winter wheat to investigate the anatomy of stomata and how stomatal traits affect crop formation. Trials in a growth chamber with 9 varieties of winter wheat were conducted under controlled conditions to investigate adaxial and abaxial stomatal sensitivity to changes in relative air humidity. In field trials, stomatal conductance, but not stomatal density or ratio, was positively related with yield. In growth cabinet experiments, adaxial stomata of winter wheat varieties were more sensitive to changes in relative air humidity than abaxial stomata. By understanding how stomatal traits are related to grain yield we can breed wheat varieties more suitable for changing climate conditions.