Ecological and biological explanation of genotype environment interaction of common winter wheat (Triticum aestivum L.)

Nikolay Tsenov, Todor Gubatov, Ivan Yanchev

Abstract: Objectives of the study: In a multi environmental field experiment (MET), which included twenty-seven varieties of common wheat, were studied in twelve different environments. The aim of the study is to gather additional information on the influence of meteorological factors related to the locations and the effects of the environment on the components of productivity in their influence on Genotype by Environment interaction (GEI) for grain yield. Experimental approach: A total of nine environmental parameters were analyzed as follows: TA-average daily air temperature, Tmax - absolute maximum temperature, Tmin- absolute minimum temperature, GDD (Growing Degree Days) - sum of active temperatures required by plants for growth and development and the SP- sum of precipitation during the growing season. Three of the parameters that differ significantly: average daily air temperature, sum of active temperatures and precipitation are divided into two groups: during the autumn winter period (from germination to the end of tillering stage (Z10-Z29) - with a suffix (a-autumn) and during the active spring vegetation (from the beginning of the stem elongation stage to full maturity (Z30-Z99), with suffix (s-spring): TAa, TAs; GDDa, GDDs; SPa, SPs. The factor (E) is a combination of the “location” and “season” factors. This approach was adopted in order to be able to specify the data on meteorological factors. The study included quantitative traits related to productivity: GY-grain yield, NPT-number of productive stems per m2, NGSnumber of grains per spike, TGW-1000 grain weight, WGS -weight of grains per spike (g), NGm - number of grains per m2, EED - date of ear emergence (number of days from 1 January), HI - harvest index and HOS – height of the stem. The interactions between the main factors (G and E) and the effects of meteorological and genetic factors, as co variables were analysed by applying three well known multi-regression models: AMMI, FR, PLS. Key results: Genotype by Environment interaction for grain yield is very pronounced, with significant principal components reaching in number of PC10. Against the background of this tangible interaction, it was found that the meteorological factors: Tmin, TAa, TAs; GDD, SPa and SPs have a significant effect on the genotype. In turn, the factor “E” interacts with the traits NGm, TGW, EED, WGS and HI, whose shares are included in the overall value of GEI. Conclusions: The main climatic parameters of the environment - temperature and rainfall, have a serious impact on (G) in its GEI, relative to grain yield. The main factor (E) directly affects important traits, such as TGW, WGS, HI, NGm, whose effects on yield have a significant share in the total GEI.

Keywords: AMMI; factorial regression; genotype x environment; stability; wheat

Date published: 2022-08-16