Phenotypic variation of spike index of winter wheat (Triticum aestivum L.) grown under limited soil conditions

Phenotypic variation of spike index of winter wheat (Triticum aestivum L.) grown under limited soil conditions Nataša Ljubičić, Bojana Ivošević, Miloš Pajić, Vera Popović, Vuk Radojević, Dragana Popović, Marko Kostić INTRODUCTION: Soil and climatic conditions are one of the most important factors affecting grain yield of wheat. The ability of a wheat cultivar to produce high and stable yield over a wide range of environments plays a major role in food security. However, since different morpho-physiological traits have been proposed as key traits associated with grain yield potential of wheat, its assessment could greatly contribute to improve grain yield. OBJECTIVES: The objective of this research was to estimate the responses of eleven winter wheat genotypes (Mina, Sofija, Tiha, Anastazija, Nevesinjka, Evropa 90, Novosadska rana-5, Dragana, Ljiljana, Simonida, Zugoly) under specific growing conditions of halomorphic soil, solonetz type. During the two vegetation seasons, phenotypic variability and genotype by environment interaction (GEI) for spike index of wheat genotypes was studied. METHOD / DESIGN: The experiment was set up on the solonetz soil and consisted of control (non-ameliorated solonetz soil) and treatments with two levels of soil amelioration using phosphor gypsum, in amounts of 25 and 50 tha−1. The additive main effects and multiplicative interaction (AMMI) models were used to quantify the genotype by environment interaction (GEI). RESULTS: The combined ANOVA showed that the phenotypic expression of spike index was significantly influenced by environmental variations, because the significant variance explained 48.8 % of the total variation, while genotype contributed with 7.8 % of the total variation of the experiment. Genotype by environment interaction expressed no significant mean square, while additional analysis of GEI using the IPCA (Interaction Principal Components) analysis showed a statistical significance of the first main component IPCA1. First source of variation IPCA1 explained 55.6 % of the GEI variation for the spike index of wheat. CONCLUSIONS: The results of this study showed that wheat genotypes responded differently to different levels of soil amelioration and significant wheat spike index variation was noticed due to different environment conditions. Spike index variation also de- pended on tested genotype, as well as vegetation season. Genetics analysis of different wheat genotypes grown in different agroecological conditions contributes to their better utilization, as well as selection for crosses in wheat breeding programs.