Karyotyping and Localization of Nucleolar Organizer Regions in Garlic, Allium sativum L

Abstract

The cytological features including chromosome counts and karyotypic features were investigated in a local cultivar of Allium sativum L. from Pakistan. Localization of NORs of chromosomes was also carried out. Actual lengths, relative lengths, short/long arm ratios of mitotic chromosomes were calculated from best five metaphase plates. Total relative length of chromosomes ranged from 7.5% to 5.0% and short/long arm ratios ranged from 1 and 0.5. Chromosomes 1 and 2 were median and the rest of the chromosomes was sub-median. N-banding was successfully used for identifying the bands at 4 NORs of chromosomes, whereas only two of them were darkly stained after silver nitrate staining.