Univrsity of Tehran Press Iranian Journal of Field Crop Science 2008-4811 53 2 2022 06 22 Genetic architecture of two populations of Nepeta racemosa in Iran Genetic architecture of two populations of Nepeta racemosa in Iran 165 176 89485 10.22059/ijfcs.2021.301672.654717 FA Fereshteh Asadi Karm Agronomy and Plant Breeding Department, Faculty of Agriculture, University of Tehran,Karaj, Iran Abdolhadi Hossein Zadeh Agronomy and Plant Breeding Department, Faculty of Agriculture, University of Tehran,Karaj, Iran 0000-0003-2241-2359 Hosein Mirzaie-Nodousha Research Institute of Forests and Rangeland, Agricultural Research, Education and Extension Organization (AREEO), Tehran, Iran MohammadReza Bihamta Agronomy and Plant Breeding Department, Faculty of Agriculture, University of Tehran,Karaj, Iran 0000-0003-0614-0963 Journal Article 2020 05 12 <em>Nepeta racemosa </em>Lam. (family Lamiaceae) is considered for its valuable medicinal compounds such as nepetalactone and is growing in several parts of Iran. In order to study existing genetic variation within and between populations for the first time, this research was performed on two populations of this species to investigate the genetic architecture of existing variation of the two populations. In this regard, at full maturity, open-pollinated seeds were collected based on single plants from two habitats of the species, during 2018, to be investigated as the half-sib families. Field experiment was performed in a randomized complete block design with three replications, in which eight morphologic characters were recorded on 277 single plants from 20 half-sib families of the two populations. Genetic variance components were estimated using biometrical variance components of the two populations, so that heritability of the characters were also estimated. Results of analysis of variance showed that family effect component was highly significant for majority of the studied traits of two populations. Based on the genetic variance components, the family component of variance was more effective than progeny component for the first population in plant height, crown diameter and biomass yield traits. Almost the same situation with minor differences was observed on the second population. In spite of small size of the studied populations, high heritability values of several traits indicated their suitable genetic potential. Although significant genetic variation and high heritability values were observed in the most studied traits, low heritability values of some other traits indicated the necessity of reconsidering the management on the natural populations. Constituting artificial gene pools, using the families with high performances could be a dual purposes strategy, in order to conserve the valuable gene pool as well as utilizing their potentials in breeding programs. <em>Nepeta racemosa </em>Lam. (family Lamiaceae) is considered for its valuable medicinal compounds such as nepetalactone and is growing in several parts of Iran. In order to study existing genetic variation within and between populations for the first time, this research was performed on two populations of this species to investigate the genetic architecture of existing variation of the two populations. In this regard, at full maturity, open-pollinated seeds were collected based on single plants from two habitats of the species, during 2018, to be investigated as the half-sib families. Field experiment was performed in a randomized complete block design with three replications, in which eight morphologic characters were recorded on 277 single plants from 20 half-sib families of the two populations. Genetic variance components were estimated using biometrical variance components of the two populations, so that heritability of the characters were also estimated. Results of analysis of variance showed that family effect component was highly significant for majority of the studied traits of two populations. Based on the genetic variance components, the family component of variance was more effective than progeny component for the first population in plant height, crown diameter and biomass yield traits. Almost the same situation with minor differences was observed on the second population. In spite of small size of the studied populations, high heritability values of several traits indicated their suitable genetic potential. Although significant genetic variation and high heritability values were observed in the most studied traits, low heritability values of some other traits indicated the necessity of reconsidering the management on the natural populations. Constituting artificial gene pools, using the families with high performances could be a dual purposes strategy, in order to conserve the valuable gene pool as well as utilizing their potentials in breeding programs. https://ijfcs.ut.ac.ir/article_89485_59500d1cd426514d5902849330f16313.pdf