Using the GY* trait interaction in ecological field trials to evaluate grain yield of wheat varieties

Todor Gubatov1, Nikolay Tsenov1 and Ivan Yanchev2
1 Wheat Breeding and Seed production Department, Agronom I Holding, Dobrich 9300, Bulgaria
2 Agricultural University, Department of Plant Growing, Plovdiv 4000, Bulgaria


Gubatov, T., Tsenov, N. & Yanchev, I. (2021). Using the GY* trait interaction in ecological field trials to evaluate grain yield of wheat varieties. Bulg. J. Agric. Sci., 27 (2), 333–341

Setting and purpose: The purpose of this study is to investigate the possibility of an integral grain yield estimation by taking into account the genotype*environment interaction of yield traits in winter common wheat.
Methods: At three main locations for the grain production in Bulgaria, 40 winter common wheat varieties were studied. Several productivity traits have been studied as follows: height of stem (HOS), number of productive tillers per m2 (NPT); number of grains per spike (NGS); thousand grain weight (TGW), weights of grain per spike (WGS), the number of grains per m2 (NGm), total above-ground biomass (TBM), harvest index (HI) and grain yield (GY) itself. A new methodology is used to assess the behaviour of each of the varieties, based on the relationship of its grain yield with some productivity traits, by measuring their change in different environmental conditions.
Key results: The interaction of genotype x environment is essential for each of the tested traits. The variation of each of them is examined against the background of the others, and then evaluated through its relationship to grain yield. An integrated assessment of varieties is applied through the interaction of their traits and yield components (GY*T) with environmental conditions. Nevertheless of the close means of traits in the tested varieties, a significant difference was found between them.
Conclusions: The established Mean Superiority Index (MSI) allows them to be properly stacked and grouped versus check varieties. The approach applied may group successfully varieties by traits that effect grain yields. The reasons for the specific grain yield of each of the varieties are analyzed by the combination of some character, which are dynamically variable according to the environments. Evaluation of a large number of varieties is fully possible by using the GY*trait approach that allows determination of their suitability for production and breeding value, as well.

Keywords: wheat; grain yield; genotype; environment interaction; productivity traits

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