Mitotic squash preparations
Mitotic squash preparations were carried out on root tip meristems of the investigated taxa. Roots were generated by sowing the bulbs of the investigated taxa of Allium in sand. Roots of Allium tuberosum were collected from germinated seedlings. Root tips of the related taxa of Allium were collected from the potted plants. All the root tips were collected at the periods showing peak mitotic frequency i.e. between Research Article
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10 a.m. to 11 a.m. The root tips were pretreated with 0.05 % colchicine for 2 hours at 12°C. The pretreated root tips were then thoroughly washed with distilled water and fixed in 1:3 acetic acid – ethyl alcohol mixture overnight, followed by 3-7 minutes treatment in 45% acetic acid. Root tips were hydrolysed in 1N HCl at 60°C for 5-7 minutes as suitable for different species. Squash preparations of the apical 0.5-1.0 mm root tips were made in 2% aceto-orcein following Sharma and Sharma, 1980.