BIODIVERSITAS ISSN: 1412-033X Volume 19, Number 2, March 2018 E-ISSN: 2085-4722 Pages: 720-725 DOI: 10.13057/biodiv/d190246 Karyomorphological variations in some populations of Allium subgenus Melanocrommyum section Acanthoprason in Iran HASSAN MASTALI, MAHBOOBEH ZARE-MEHRJERDI ♥ , MARYAM NOROUZI, JALAL REZAEI Department of Horticulture, College of Aburaihan, University of Tehran. Tehran, Iran. Tel./Fax. +98-21-36041089, ♥ email: mzarem@ut.ac.ir Manuscript received: 15 January 2018. Revision accepted: 28 March 2018. Abstract. Mastali H, Zare-Mehrjerdi M, Norouzi M, Rezaei J. 2018. Karyomorphological variations in some populations of Allium subgenus Melanocrommyum section Acanthoprason in Iran. Biodiversitas 19: 720-725. Allium is the largest genus of Amaryllidaceae comprising more than 900 species belonging to 15 subgenera. Iran is reported to be a center of diversity for subgenus Melanocrommyum. Acanthoprason is a section in this subgenus. In this paper, karyomorphological variations of nine populations of four species including Allium derderianum, A. kurdistanicum, A. minutiflorum and A. subakaka of the section Acanthoprason growing in Iran were undertaken using squash technique and 2% (w/v) aceto-orcein stain. All of the populations have the same chromosome numbers 2n = 2x = 16 with the exception in Kochka population of A. derderianum 2n = 18. In the present study, the chromosome number of A. minutiflorum and new chromosome number of A. derderianum were revealed for the first time. Chromosomal characteristics were determined using photographs complemented by cluster analysis. According to dendrogram generated by the unweighted pair-group method with arithmetic average (UPGMA) cluster analysis, nine populations studied were separated into five groups at a cut off value of 5. Karyotype analysis indicated that Allium species studied here generally have metacentric and submetacentric chromosomes and symmetric karyotypes. Results of the present study revealed the natural variation in nine populations of four species of Acantoprason section which can further serve conservation and breeding planning.฀ Keywords: Acanthoprason, chromosome number, karyotypes, new count, population INTRODUCTION Allium is the largest genus of Amaryllidaceae comprising more than 900 species belonging to 15 subgenera. There is a main center of diversity in the eastern Mediterranean area, Southwest and Central Asia (Fritsch and Abbasi 2013). The chromosome numbers of more than 600 Allium species are known according to the Index to Plant Chromosome Numbers (http://www.tropicos.org/Project/IPCN). The most common basic chromosome number in Allium is x = 8, but other numbers (x = 7, 9, 10, 11) and various ploidy levels from diploid to hexaploid (2n = 14-68) have also been reported (Li et al. 2010). Melanocrommyum is the second largest subgenus, comprising about 169 accepted species and subspecies grouped into 20 sections and 22 subsections (Fritsch et al. 2010; Fritsch 2012). Species of subgenus Melanocrommyum are naturally found in Middle East, especially in Iran and Turkey (Behcet and Rustemoglu 2012; Fritsch and Abbasi 2013; Ozhatay and Genc 2013). There are 10 sections and 82 species belonging to the subgenus Melanocrommyum in Iran. The sections of the subgenus in Iran are as follows: sect. Melanocrommyum, sect. Acanthoprason, sect. Asteroprason, sect. Compactoprason, sect. Decipientia, sect. Kaloprason, sect. Megaloprason, sect. Procerallium, sect. Pseudoprason and sect. Regeloprason (Fritsch and Abbasi 2013). In this research, the ploidy levels, morphology of chromosomes, karyotype formula and symmetry indexes of nine populations related to four species including A. derderianum, A. kurdistanicum, A. minutiflorum and A. subakaka of the section Acanthoprason have been studied. MATERIALS AND METHODS The examined plant materials are presented in Table 1. Plant materials were collected from different regions of Iran (Figure 1). Ten randomly selected individuals per population were used for karyological studies. Karyological observation was made on mitotic metaphase cells of root tips obtained from planted bulbs which were collected in natural habitats from Iran according to Ao (2008) with some modifications. Briefly, root tips were pretreated in 8-hydroxyquinoline 0.002 M for 3-5 hours in room temperature, washed with distilled water and fixed in Carnoy's solution (3:1, absolute ethanol: glacial acetic acid) for 24 hours and finally kept in 70% ethanol at 4°C. The root tips were rinsed with distilled water for 15 min before being hydrolyzed for 6 minutes in 1 N HCl at 60°C and stained with acetic-orcein 2% and squashed. A minimum of 10 slides possessing well-spread chromosomes was used for each population. The observations of the best metaphase plates were made using an Olympus BX-40 (light microscope Olympus, Tokyo, Japan) equipped with a 100×/1.3 NA oil objective and amounted DP12 digital camera (Olympus). Chromosome characteristics were measured from 10 enlarged well- spread metaphase cells of each population, using Ideokar ver.1.2 software.฀