University of Isfahan Taxonomy and Biosystematics 3115-9001 14 50 2022 05 22 Molecular Phylogeny and Divergence Time Estimation of Onobrychis sect. Onobrychis (Fabaceae) based on nrDNA ITS تبارزایی مولکولی و تخمین زمان واگرایی بخشۀOnobrychis از سردۀOnobrychis (تیرۀ باقلائیان) براساس توالی‌‌های nrDNA ITS 95 114 27086 10.22108/tbj.2022.134107.1204 EN Anahita Hadadi Ph. D. Student of Plant Systematics, Department of Plant Biology, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran Akram Kaveh Ph. D. Graduate of Plant Systematics, Department of Plant Biology, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran Hanyieh Nafisi Postdoctoral Fellowship of Plant Systematics, Department of Plant Biology, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran Shahrokh Kazempour-Osaloo Professor of Systematic and Evolutionary Botany, Department of Plant Biology, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran Journal Article 2022 06 20 Abstract This study examined the phylogenetic analysis and estimating divergence time of O. sect. Onobrychis by using nrDNA ITS sequence data. A total of 60 species from the section Onobrychis, seven species of the five sister sections belonging to O. subgen. Sisyrosema and eight species of other genera of the tribe Hedysareae (Eversmannia subspinosa ، Greuteria argyreum، Corethrodendron multijugum ، Taverniera cuneifolia، Hedysarum polybotrys، Sulla spinosissima, Alhagi maurorum) were chosen as outgroups. Phylogenetic analyses were performed by maximum likelihood and Bayesian methods. The results showed that O. sect. Onobrychis was monophyletic and composed of two main well-supported clades. The first clade included annual and perennial species with long wings, often with the basic chromosome number x= 8. The second clade comprised of perennial species with short wings and two annuals with long wings, having the basic chromosome number x= 7. Sect. The divergence time estimation of this section was analyzed with BEAST. The section originated from 11.96 Mya in middle Miocene and subsequently diverged into two linages at 9.29-9.58 Mya. Key words: Divergence Time, Fabaceae, nrDNA ITS, Onobrychis, Phylogeny. Introduction The genus Onobrychis Mill. comprises ca. 170 annual or perennial herbs divided into two subgenera and nine sections. At the current status, O. sect. Onobrychis with merging sects. of Lophobrychis and Dendrobrychis is the largest section of the genus. Materials and Methods In the present study, the phylogenetic analysis and estimating divergence time of O. sect. Onobrychis were conducted using nrDNA ITS. A total of 60 species from the section Onobrychis, seven species of the five sister sections belonging to O. subgen. Sisyrosema and eight species of other genera of the tribe Hedysareae (Eversmannia subspinosa, Greuteria argyreum, Corethrodendron multijugum, Taverniera cuneifolia, Hedysarum polybotrys, Sulla spinosissima, and Alhagi maurorum) were chosen as outgroups. The phylogenetic analyses were performed via maximum likelihood and Bayesian methods. The divergence times estimation of this section was analyzed with BEAST. Findings The results showed that O. sect. Onobrychis was monophyletic and composed of two main well-supported clades including clade “A” and clade “B”. Each clad was divided into several subclades. Results and Conclusions The first clade included annual and perennial species with long wings, often with the basic chromosome number x= 8, and the second one involved species with the basic chromosome number x= 7. It was also found that the annual species previously classified in the sect. Lophobrychis were not monophyletic, and three long-winged annual species were placed in clade “A”, and two annual long-winged species were related to short-winged perennial species, are placed in clade “B”. However, the two long-winged species O. cornuta and O. elymaitica, which were previously classified in the sect. Dendrobrychis, were placed in the clade “A”. Sect. Onobrychis originated from 11.96 Mya in the middle Miocene and was subsequently diverged into two lineages at 9.29-9.58 Mya.

https://tbj.ui.ac.ir/article_27086_9d773471fa42d4c6c4b22dd3c634ced6.pdf