Study on seed yield stability of sunflower inbred lines through GGE biplot

Abstract

The evaluation of GE interaction is an important component of the cultivar selection process in multi-environment trials (METs). GGE biplot analysis is an effective method which is based on the principal component analysis (PCA) in order to fully explore METs. The objectives of the present study were first to analyze the GE interaction in the seed yield of 15 sunflower inbred lines through the application of GGE biplot technique, as well as to identify suitable sunflower inbred lines with both mean performance and high stability. Seed yield of 15 sunflower inbred lines which were derived from 5 basic populations was tested in a randomized complete block design with three replications. These inbred lines were tested from 2008 to 2011 at the Sararood agricultural research station in western Iran, which created 6 environments in total. The results of variance analysis showed the significance of environmental variance compared to the genotype and GE interaction variances. The first two principle components (PC1 and PC2) together explained 68.2% of the total variability, so most of the information could be graphically displayed in the PC1 vs PC2 biplot. Polygon view of GGE biplot revealed that G3 was the inbred line with the highest seed yield in four out of six environments. The average environment coordinate (AEC) biplot showed that G3 with the highest mean yield was a highly stable inbred line as it was positioned close to the AEC abscissa. The second highest yielding and most stable inbred line was G10. The biplot of comparison of the sunflower inbred lines with the ideal genotype revealed that G3 was the closest inbred line to the ideal cultivar. Therefore, this inbred line seems to be widely adapted across several environments. According to the biplot of the ideal environment it was concluded that E1 was the closest to ideal environment and therefore the most desirable of all six environments. So, E1 is the most effective for the selection of superior inbred lines.