Influence of weather conditions during the pre-vegetation period on productivity and yield qualities of soft spring wheat seeds

Abstract

Eleven genotypes of soft spring wheat were studied in a series of field and laboratory experiments in 2014 - 2018. The laboratory test included accounting for seed germination and assessing the physiological parameters of seedlings (number of seminal roots, dry matter mass of roots and shoots and their ratio (RSR index)). The field tests included phenological observa-tions, assessment of genotypes by productivity and average yield. The average yield of wheat during the years of study was 1.93-4.92 t/ha and depended on weather conditions during the period of grain formation. The trait “1000-grain mass” was formed under the influence of the genotype (68.1%), the portion of influence of weather conditions was 11.8%. It has been established that the duration of the reproductive period of soft spring wheat in the Kirov region should be at least 40 days. Reducing the duration of the reproductive period leads to a decrease in seed germination capacity. Seeds the formation and development of which took place at the optimum temperature of 16 ºС, by germination spent the most part of seed reserve substances for the development of the aboveground part of the plant (RSR index = 0.70). Under these conditions, the varieties with a lower root index were characterized by high values of the elements of yield structure. At the increased average daily air temperature (by 2-4 oC), seeds that could germinate with a significantly higher number of seminal roots (6.6-9.0%) developed on the maternal plants. During the germination of such seeds, the plastic substances distributed evenly between the shoots and seminal roots (RSR index = 0.94-0.98). The increased influx of assimilates to root system of seedlings could be explained by the fact that the process of seed formation on the maternal plants took place under conditions close to stressful and the adapted seeds spent more reserve substances for root development.