Evaluation of heritability and genetic advance of some quality parameters in common wheat (Triticum aestivum L.) under genotype by environmental interaction
Authors: Tsenov N. , Gubatov T. , Yanchev I. 
Published: October 2022

Abstract. Growing conditions play a significant role in the yield and grain quality of winter wheat. Global climate changes and in particular in the meteorological situation in the regions typical for the crop presuppose conducting research on the newly created breeding materials for grain quality. The aim of the study is to determine the nature and magnitude of the change in important parameters of grain quality, under the influence of typical environmental conditions for growing common wheat. The working hypothesis suggests that most of the parameters have a good genetic basis that would allow the selection to lead to their increase. In a multi environmental field experiment involving five test locations over three consecutive years, changes in eight grain quality parameters were investigated reflecting different aspects of the end-use quality. The study involved 40 samples of wheat developed by the breeding company "Agronom" in the last 20 years. With the help of modern methods for statistical analysis, the effect of the main breeding factors "location", "year" and "genotype", the limits of variation and the correlations between them have been established. The real possibilities for selection and breeding of each parameter have been analyzed, against the background of the rest of the group. Quality parameters change significantly from the three factors studied. The interaction "genotype x year" has the strongest influence on each of them. The "location x genotype" interaction is not a factor that affects the parameters. Only Deformation energy shows a significant share of the genotype, while the other two factors have a negligible influence on it. Each of the studied parameters, without exception, changes both adequately (linearly, IPC1) and inadequately (nonlinearly, IPC2) when the conditions change during the studied seasons. This nature of change is the reason for the relatively weak positive correlations between the parameters, as well as for their low heritability coefficients in a broad sense. Against the background of the data, the values of Genetic advance are indicated, with which each of them can be increased by selection. There are both positive and negative correlations between the parameters, the direction and value of which must be taken into account in the attempt to change them. An effective selection can be made on the parameters Extensibility index, Deformation energy and P/L ratio which have the strongest genetic control (H2> 0.60), which against the background of the strong influence of the environment ("location", "year", "location x year”) can lead to genetic advantage with 12% (Extensibility index), 17% (Deformation energy), 51% (P/L) of their present value. A selection based on PC or Wet gluten content parameters that have a direct effect on overall quality can also be effective (H2 =0.58-0.63). Instead, it would be more prudent to monitor, not so much their quantitative, but their qualitative composition, the accumulation of known or new alleles of glutenins (Glu) and gliadins (Gli), for which there is specific information that they are directly related to high grain quality.