Genetic control of the number of grains on corn cob

Abstract

The evaluation of the combinational ability of maize I-lines was carried out on the basis of “the number of grains on the cob”. This parameter is one of the significant components of the structure of plant productivity and harvest and is directly dependent on the number of grain rows and the number of grains in a cob row. The quantitative manifestation of this trait is significantly influenced by environmental conditions. A negative correlation of the studied trait with the seed size was revealed. Growing conditions strongly affect the value of the studied trait. The source material for breeding works with low and high indicators of combinational ability in terms of the number of grains on the cob is determined. Overdomination has a predominant effect in the manifestation of the number of grains on the cob. The values of the H1 dominance component are significant and notably higher than the values of the D component, which characterizes the variability caused by the additive action of genes. The values of the H2/4H1 component indicate an uneven distribution among the parental lines of alleles with positive and negative effects. The number of genes or gene groups that control the number of grains on the cob varies from 2 to 3. In 2016–2018, the paratypical variance component (E) had a significant influence on the formation of the number of grains.