Global climate changes have caused a significant weather oscillation. The objectives of this study were to determine the influence of weather conditions on the association of soybean seed yield and yield components, to find out the magnitude and effect of each component and their reaction to environmental stress. Seventy-four soybean varieties from nine geographical origins were studied during two seasons (2015 with less rainfall and increased temperatures and 2016 with increased humidity and moderate temperatures) at the Croatian Centre for Agriculture, Food and Rural Affairs in Osijek, Croatia. Correlation and path analysis were used to examine the association of the studied traits. The variance analysis revealed significant (P<0.01) effect of genotype, year and their interactions on all examined traits. During both seasons the seed yield was in significant and positive correlation with seed number per plant, pods number per plant, seed number per pod and 1,000-seed weight. All the traits mentioned had a stronger correlation with the yield in the dry 2015 compared to the year 2016. The seed number per plant had the highest correlation coefficients and a high and positive direct effect on seed yield in both years. Therefore, the selection of high yielding genotypes based on this trait can be done directly regardless of the variable weather conditions. The hierarchical clustering of varieties resulted in eight clusters in both years, confirming high genetic variability of the examined varieties. In 2016 one cluster that mainly consisted of varieties typical for the breeding programs of this region was singled out.Keywords: correlation, hierarchical clustering, path analysis, seed yield, soybean, weather oscillation, yield component
SažetakGlobalne klimatske promjene uzrokuju sve veće vremenske oscilacije. Ciljevi ovog istraživanja bili su odrediti utjecaj vremenskih čimbenika na povezanost prinosa zrna soje i komponenti prinosa, ispitati jačinu i učinak svake komponente te njihovu reakciju na okolišni stres. Tijekom dvije vegetacijske sezone (2015. sa sušnim uvjetima i povišenim temperaturama i 2016. s vlažnim vremenskim uvjetima i umjerenim temperaturama) pri Hrvatskom centru za poljoprivredu, hranu i selo u Osijeku proučavane su sedamdeset četiri sorte soje podrijetlom iz devet različitih geografskih izvora. Za ispitivanje povezanosti proučavanih svojstava korišteni su korelacijska i path analiza. Analiza varijance pokazala je značajan (P<0,01) učinak genotipa, godine i njihove interakcije na sva ispitivana svojstva. Tijekom obje sezone prinos sjemena je bio u signifikantnoj i pozitivnoj korelaciji s brojem zrna po biljci, brojem mahuna po biljci, brojem zrna po mahuni i masom 1000 zrna. Navedena svojstva su imala jaču korelaciju sa prinosom u sušnoj 2015. u usporedbi s 2016. godinom. Broj zrna po biljci je imao najviši koeficijent korelacije te visok i pozitivan izravni učinak na prinos u obje godine pa se izbor genotipova visokih prinosa na temelju ovog svojstva može obaviti izravno bez obzira na pr...