Graphic Analysis of Trait Relations of Spinach (Spinacia oleracea L.) Landraces Using the Biplot Method

Abstract

Interest in growing spinach (Spinacia oleracea L.) in Iran is increasing due to its potential returns relative to other leafy vegetable crops. An experiment was conducted to examine the influencing characters on spinach by using 54 spinach landraces with application of the biplot methodology in visualizing research data. The study revealed that genotype by trait (GT) biplot can graphically display the interrelationships among traits and facilitate visual comparison of genotypes. The first two principal components (PC1 and PC2) of the site regression model accounted for 66% of the total variation in 54 landraces and accounted for 78% of the total variation in 16 clusters which are generated from cluster analysis of above landraces. The polygon view of GT biplot suggested seven sections for the 54 landraces and suggested four sections for the 16 clusters. The vertex landrace G38 had longest days to flowering and the vertex landrace G20 had most values for the other measured traits. The other vertex genotypes were not good in any traits. The vertex clusters were C1, C4, C8, and C14 which cluster C8 had the highest values of flowering period, leaf length and petiole diameter while, cluster C14 had the highest values for the other traits. The results can be used to design efficient breeding strategies in spinach.

Keywords

• genotype by trait (GT) biplot
• dry yield
• polygon view
• site regression