Actively growing root tips still with germinating bulb were treated in 0.05% colchicine solution for 5 hours.
Then the bulbs were left in water few 24 hours. After that the root tips were cut and fixed in Acetic Alcohol (1:3). Such fixed root tips were supplied in the class.
Staining and slide preparation were done as usual.
The slides were observed under the microscope. The following conditions abnormal were observed, besides the normal mitotic phases.
• Late prophase with tetraploid chromosomes.
• Much bigger and wider metaphase plate, indicating tetraploid condition.
• Much bigger daughter chromosome groups in anaphase.
• Occurrence of micronucleus/micronuclei, along with bigger daughter nucleus.
From the above noted observations, it was evident that colchicine treated resulted these conditions.
Late prophase with tetraploid chromosome
Metaphase at tetraploid condition (Metaphase arrest)
Two separate anaphase group
Micronucleus in daughter cell
Study 8 Checklist Remarks