CROP YIELD AND CONCENTRATION OF PHOTOSYNTHETIC PIGMENTS IN THE LEAVES OF THE SPRING WHEAT WHEN THEM SUFFERING FROM SEPTORIA BLIGHT

Abstract

The authors explore the varieties and perspective breeding lines of the North-East Federal State Budgetary Scientific Institution with varying degrees of resistance to Septoria by yield and composition of the pigment complex in the leaves under the conditions of the Kirov region, were studied . Under the conditions of the growing season in 2017, characterized by excessive moisture, the strong development of a fungal infection (the degree of damage to the leaf is 22.0-62.3%) led to a decrease in the overall productivity of plants. The correlation coefficient between the defeat of Septoria and cereal and biological yields took average negative values (r = -0.43 and -0.44). The difference among the average parameters in the groups of moderately stable and susceptible varieties was 0.23 t/ha for grain yield and 0.49 t/ha for aboveground biomass. From the exit phase into the tube to heading an increase in the content of chlorophilic pigments and a decrease in the content of carotenoids per unit d ry mass of the leaf were observed in all varieties. However, in the group of susceptible varieties, the increase in chlorophyll a + b was less significant, and the content of carotenoids decreased more dramatically. In 2018, with a lower infectious load (the degree of damage was 9.5-47.0%), there were no significant differences in yield and the number of chlorophylls a and b in varieties of different resistance groups. In most cases, the content of chlorophylls a + b and carotenoids decreased by the flowering phase. C-64 and C-65 selection lines, tolerant to septoria, maintained a consistently high level of pigments. The correlation analysis reflects that the content of photosynthetic pigments in the exit phase into the tube was reliably associated with the development of the vegetative mass of plants, and with grain yield it happened in the flowering phase. No significant connection between the defeat of Septoria and the number of chlorophylls a and b in the flowering phase was found, but there was a decrease in the percentage of carotenoids in the total amount of pigments, depending on the extent of injury.