Evaluation of Genetic Variability of Agro-Morphological Traits in Iranian Peppers Population (Capsicum annuum L.)

The study of genetic diversity is an important step in planning crop breeding programs. According to researchers, diversity of the population under selection ensures the desired results in breeding programs. In this regard, using the capacity of local populations to create new cultivars and achieve maximum diversity is very efficient. Therefore, the purpose of this study is to investigate the agro-morphological traits of pepper populations to identify the breeding potential of local populations for producing hybrid cultivars.

In the present study, 30 populations of Iranian peppers were planted in five replications in the research greenhouse of Department of Plant Production and Genetics of Urmia University, in order to study the genetic variability in terms of some agro-morphological traits. The experiment was conducted in a completely randomized design (CRD) in pot conditions in  2016-2017. In this study, variance analysis (ANOVA) and mean comparison of traits by Duncan's multiple range test, estimation of phenotypic correlation by Pearson method and principal component analysis on correlation coefficient and also cluster analysis by Ward method has done and realized. Also, the variance components, heritability (h2), phenotypic coefficient of variation (PCV), genotypic coefficient of variation (GCV), and environmental coefficient of variation (ECV) were calculated.

The results showed significant difference among the populations for all studied traits. The highest phenotypic coefficient of variation (PCV) (88.36) was observed for single fruit weight and also the highest genotypic coefficient of variation (GCV) (83.63) was observed for the same trait (single fruit weight). The pulp weight and fruit yield (0.950) had the highest significant positive correlation coefficient and the single fruit weight and fruit number (-0.558) had the highest significant negative correlation coefficient. According to the results of hierarchical cluster analysis, the studied populations were divided into five clusters based on the studied traits. The Tabriz population in the first cluster and the Gharah Bagh-Urmia population in the fourth cluster were superior in the fruit number trait.

In this study based on the results of mean comparisons Bash Ghala (from Urmia), Nakhchivan (from Urmia) and Keshtiban (from Urmia) populations were superior in terms of most of the studied traits. Also, Bash Ghala (from Urmia), Nakhchivan (from Urmia) and Keshtiban (from Urmia) populations were in the same cluster had higher fruit yield than other studied populations. Therefore, these populations can be used as one of the top parents in the intersection with other populations to create desirable genetic compounds.