Dependence of main shoot ear grain yield from stem deposited ability of winter wheat varieties
V.V. Morgun, G.A. Priadkina, O.V. Zborovska
In field conditions, the parameters of deposited ability of the main shoots stem and the remobilization of assimilates of 3 winter wheat varieties of modern breeding (2013-2016) and 3 drought-tolerant ones of earlier breeding (1997-2008) under natural conditions were studied (Kyiv reg., Ukraine). The amount of precipitation for June 2017, during the period of reproductive development of winter wheat, was 34% from normal amount. The comparative estimation showed that the modern variety of Raygorodka and the drought tolerant variety of the earlier breeding Podolianka were the highest grain yield of main shoots ear (respectively, 1.88 ± 0.07 and 1.73 ± 0.05 g) under such conditions. Their yields were higher than other 4 varieties by 5-10%, too. Significant variations in stem dry matter weight, the content and amount of nonstructural carbohydrates in the main shoots, at anthesis, as well as full ripeness there were established between varieties. The strong correlation between the grain yield of main shoot ear with the stem dry matter weight at anthesis (r=0.82 ± 0.29) and difference of stem dry matter weight at anthesis and full ripeness (r=0.84 ± 0.27) was revealed. Both most productive varieties had the highest stem dry matter weight at anthesis, the bigger difference of its weight between at anthesis and the full ripeness and the greater relative contribution of nonstructural carbohydrates accumulated in the stem during period from anthesis to full ripeness in the grain weight it was found. The resistance of winter wheat varieties to drought is due to their ability to depose assimilates in the stem during the preanthesis period (before the grain filling) and due to the re-mobilization of the assimilates accumulated during the reproductive period it has been shown.