SStability Analysis for Seed Yield in Different Fenugreek (Trigonella foenum-graecum L.) Ecotypes using Eberhart-Russel Regression and Different Univariate Statistics Methods

Due to the high importance of fenugreek in terms of nutritional and medicine, improvement of genotypes with high yield seems to be essential. Yield is a quantitative trait that is affected by the genotype-environment interaction. In order to evaluate stability and adaptation for seed yield in fenugreek ecotypes, the experiment was carried out during growing season for three consecutive years 2011-2013 in Jiroft Station of Research and Technology Institute of Plant Production (RTIPP) of Shahid Bahonar University of Kerman. Fenugreek ecotypes including Kerman, Kordestan, Mazandaran, Ilam, Kohgiluyeh and Esfahan were studied in different environments which a number of variables iron, zinc and three different irrigation intervals in randomized complete block design with three replications were considered. Combined Analysis of Variance (ANOVA) revealed genotype × environment interaction was significant for seed yield. Stability parameters including environmental variance (S2i), genotypic variation coefficient (CVi), Wricke's ecovalence, Shukla's stability variance and Eberhart-Russel Regression parameters were applied to study stability for yield. According to the results of Eberhart-Russel based on linear regression coefficients and deviation from linear regression, Kordestan ecotype with higher seed yield than the average, linear regression coefficient equal one (bi=1), as well as lowest deviation from the regression was identified as the most stable high performance genotype, while Kerman ecotype with higher regression coefficient than one (bi>1) and the highest yield was categorized as the most unstable genotype. Moreover, based on the other parameters, Kordestan and Mazandaran ecotypes were introduced as the most stable genotypes and Kerman ecotype as the most unstable genotype. Ilam ecotype was identified with general adaptation and low performance while Esfahan ecotype showed specific adaptation for the unfavorable environments.