Relationships among oil content, protein content and grain yield in wheat (Triticum aestivum, L.)

Abstract

Assessment of health-beneficial chemicals in wheat grain and oran, such as proteins and oil is important for the breeding due to increased consume: cernands ior healthier food. Also, it is very important to know their relationships with the grein yield and to what extent they could be modified by growing conditions. The objective of this study was to investigate oil and protein contents, as well as grain yield of 25 winter wheat (Triticum aestivum, L.) varieties and to establish correlations among these traits in different environments. The field studies were performed on three different experimental sites in Serbia during two growing seasons (2009/10 and 2010/11). The investigated locations representing Serbia’s most important wheat-growing areas: Rimski Sancevi (45°20’N, 19°51'F 37 m altitude), Sremska Mitrovica (46°06'N, 19°33'E, 83 m altitude) and Pancevo (44°50 N, 20°40°E, 76 m altitude). The oil was extracted from wheat bran obtained by laboratory mi! MLU 202. Classical Rushkovsky method was used to determine oil content, while protein content was determined by the ICC 105/2 method. Significant variability was found among the genotypes for all analysed traits. In the six environments, the oil content varied from 2 “> 5.6%. with the average value of 3.8% and coefficient of variation (CV) 15.7%. The protein content ranged from 11.2% to 17.8% with the CV of 5.4%, while the grain yield varied fram 2.3 to 9.8 t/ha, with the CV of 17.8%. The average genotypic values for all environments have shown negative correlation between protein content and grain yield (r=-0.739**). This correlation was highly significant in three (E3, E4 and £6) out of six environments, while significant positive correlation between oil content and grain yield (r=0.441*) was found only in Ee. The established correlations between the traits are highly environmentally dependant and co. » modified by variable growing conditions. It will be very valuable for breeding process to identufy climatic variables and growing conditions that modify unwanted correlations, 2s well as to identify genotypes in which these correlations are not expressed !n orce iow successful breeding for improvement of both traits at the same time. For positive correlations it is also useful to know the favourable conditions in which they can be maximize