University of Isfahan Taxonomy and Biosystematics 3115-9001 15 55 2023 08 23 Chromosome Count and Karyotype Analysis of Six Brassicaceae Species in Iran بررسی عدد کروموزومی و تحلیل کاریوتایپی شش گونه‌ از خانواده Brassicaceae (شب بو) در ایران 79 88 28183 10.22108/tbj.2024.139872.1247 EN Azadeh Akhavan Roofigar Assistant Professor, Research Division of Natural Resources, Isfahan Agricultural and Natural Resources Research and Education Center, AREEO, Isfahan, Iran 0000-0009-0009-0009 Fereshteh Asadi-Corom PhD, Department of Biotechnology, Research Institute of Forests and Rangelands, Agricultural Research, Education and Extension Organization, AREEO, Tehran, Iran Adel Jalili Professor, Research Institute of Forests and Rangelands, Agricultural Research, Education and Extension Organization, AREEO, Tehran, Iran 0000-0001-6494-181X Journal Article 2023 11 22 In the present study, chromosomal data are presented for six species representing five genera within the Brassicaceae family including Odontarrhena lanigera (DC.) Španiel, Al-Shehbaz, D.A. German & Marhold (=Alyssum lanigerum DC.) 2n=16, Aubrieta parviflora Boiss. 2n=16, Matthiola flavida Boiss. 2n=12, (=Matthiola ovatifolia Bél.) M. tomentosa (Boiss.) Boiss. 2n=12, Sisymbrium erysimoides Des. 2n=14 and Sterigmostemum longistylum (Boiss.) Kuntze 2n=14. Two of the studied species (Matthiola flavida and Sterigmostemum longistylum) are reported for the first time, while the chromosomal data for the remaining species are consistent with previous findings. These species exhibit a basic chromosome number of x=6, 7, or 8. Karyotypic analyses were also conducted in the existing samples and idiogram was drawn for them. The shortest chromosomes belong to Odontarrhena lanigera (2n=16) and the longest chromosomes were observed in Matthiola flavida (2n=12) species. Key words: Cruciferae, Chromosome number, Karyotype, Ideograms, Iran. Introduction Brassicaceae is a diverse group of flowering plants recognized for their economic, ecological, and evolutionary importance. This family encompasses a wide array of species, each exhibiting varied chromosome numbers and karyotypic characteristics. Understanding the chromosomal counts and karyotypic features of different Brassicaceae taxa is important for clarifying their genetic diversity, evolution, and potential applications in agriculture and conservation. Iran, with its varied ecological conditions, hosts an impressive diversity of Brassicaceae species. Within Iran, this family comprises approximately 100 genera and over 359 species, with a remarkable 53 species endemic to the country. This taxonomic diversity and endemism underscore the region's significance in terms of plant biodiversity within the Brassicaceae family. The present research aims to conduct a comprehensive study of six Brassicaceae species in Iran, focusing on their chromosomal counts and karyotypic features. The goal of this study is to achieve chromosomal counting for several Brassicaceae species in Iran, identify two previously unreported species, and produce ideograms to demonstrate their karyotypes. Materials and Methods In this study, karyotype analysis was conducted on mitotic metaphase chromosomes using the squash technique. To prepare the chromosomes for analysis, root tips were treated with a 0.01% aqueous colchicine solution for 2 hours at room temperature, followed by 14 hours at 4 °C. Subsequently, the root tips were fixed using Carnoy's solution, a mixture of glacial acetic acid and ethanol, and then preserved in 70% ethanol. For enhanced chromosome visualization, the materials underwent hydrolysis in 1 N HCl for 10 minutes at 60 °C, followed by staining in 2% aceto-orcein for 3 hours. After staining, the roots were gently squashed in 45% acetic acid, and the best metaphase plates were selected for imaging. For karyotype analysis, the chromosomes were sorted by length, and chromosome pairs were arranged following the Levan classification. Ideograms were constructed for all species, and karyotype asymmetry parameters, including TF%, AR, As K%, and Syi, were comprehensively assessed. Research Findings For the first time, we report the chromosome numbers for two species, namely Matthiola flavida and Sterigmostemum longistylum. Chromosome numbers for the other four species (Odontarrhena lanigera = Alyssum lanigerum, Aubrieta parviflora, Matthiola tomentosa = M. ovatifolia, and Sisymbrium erysimoides) have been previously documented. A karyological analysis of Odontarrhena lanigera (DC.) Španiel, Al-Shehbaz, D.A.German & Marhold (= Alyssum lanigerum DC.) revealed a diploid chromosome number of 2n=2x=16, with seven metacentric and one submetacentric chromosome. Compared to other studied species, this species' chromosomes were the shortest in length. Additionally, it exhibited the highest TF% (0.44) and Syi% value (0.77), while having the lowest S% (44%) and Ask% value (0.55) among all the investigated species. The results of this study confirmed a diploid chromosome number of 2n=2x=16 for Aubrieta parviflora Boiss., consistent with earlier reports on the somatic chromosome number. The karyotype of this species consisted of six metacentric and two submetacentric chromosomes. Discussion of Results and Conclusions In Matthiola flavida Boiss., our analysis indicated a chromosome count of 2n=2x=12 and a karyotypic formula of 4m+1sm+1st. This is the first reported chromosome count for M. flavida, providing valuable insights into the cytology of this species. Matthiola tomentosa Bél. (=Matthiola ovatifolia (Boiss.) Boiss.) is diploid with a chromosome count of 2n=2x=12. The karyotype consists of metacentric and subtelocentric chromosomes, with a formula of 4m+2st. This finding aligns with previous reports. Notably, it exhibited the lowest TF% (0.34) and Syi% value (0.51), while having the highest S% (55%) and Ask% value (0.65) among the studied species. Sisymbrium erysimoides Desf. is a diploid species with a chromosome count of 2n=2x=14, this species had six pairs of metacentric and one pair of submetacentric chromosomes, consistent with earlier findings. Sterigmostemum longistylum (Boiss.) Kuntze. was identified as diploid with a chromosome count of 2n=2x=14, and a karyotypic formula of 3m+4sm. This is the first report of both the chromosome number and karyotype details for this species. To conclude, this study presents the first reported chromosome counts for Matthiola flavida and Sterigmostemum longistylum, while confirming and detailing the chromosomal numbers and karyotypic features for several Brassicaceae species in Iran.

https://tbj.ui.ac.ir/article_28183_9662e92e8900e764365ef9a06a277d25.pdf