Using the shifted multiplicative model to separability genotypic effects in grass pea (Lathyrus sativus L.)

In most experiments comparing the cultivars, the interpretation genotype × environment interaction is complex, and environmental and genotypic effects are not separable. Shifted multiplicative model (SHMM) provides a powerful analytical tool for the discriminating of genotypic effects from environmental effects and discriminating of environmental from genotypic effects. In this study 10 elite lines of Grass pea (Lathyrus sativus L.) local landrace with Naghadeh (as a control) in a randomized complete block design with three replications were analyzed using SHMM models. Using cluster analysis based on the proposed distance measure produces four final groups of environments with a SHMM1. The first three years of Gachsaran and the first year of Ilam and tow last years of Lorestan located in one cluster, the first two years of Lorestan located in separate cluster, Ilam’s last two years and Gachsaran last year were grouped in a cluster. The second year of Ilam ranked in a separate cluster as well. In each of these clusters, the genotypes did not show crossover effects with themselves, and SHMM1 model has had adequate fitting in each cluster. The results of SHMM model was confirmed using the graphical method. Results revealed that the least and the highest cross over interactions in different years among genotypes at Gachsaran and Ilam locations, respectively.