The following statements are made regarding colchicine treatment in plants for inducing polyploidy.
A. In colchicine-treated cells, sister chromatids cannot separate during anaphase, leading to chromosome doubling when the nucleus reforms.
B. Colchicine stimulates endoreduplication in the treated cells, bypassing cytokinesis to yield polyploid cells in a process called “C-mitosis”.
C. In sterile interspecific hybrids, colchicine treatment may restore fertility by converting them into amphipolyploids.
D. Colchicine treatment during meiosis has no effect, as it only acts on mitotic cells.
E. Colchicine binds to tubulin and prevents spindle fibre formation during mitosis.
Which one of the following options represents a combination of all correct statements?

Correct option is A

Correct Answer
(a) A, C and E only
Explanation:
Colchicine inhibits spindle fibre formation by binding to tubulin. As a result, sister chromatids fail to separate at anaphase, and when the nuclear membrane reforms, chromosome number doubles, producing polyploid cells. In sterile interspecific hybrids, chromosome doubling by colchicine allows proper pairing of homologous chromosomes, restoring fertility and forming amphipolyploids.
Information Booster
· Colchicine is widely used in plant breeding to artificially induce polyploidy
· Polyploid plants often show larger cell size, increased vigor, and improved yield
· Amphipolyploidy is important in crop evolution, such as in wheat and cotton
· Spindle inhibition is the key cellular mechanism behind colchicine action
· Colchicine-induced polyploidy occurs mainly during mitotic divisions in meristematic tissues
Additional Knowledge
Statement B is incorrect because colchicine does not stimulate true endoreduplication; “C-mitosis” refers to mitosis without spindle formation, not bypassing cytokinesis through endoreduplication.
Statement D is incorrect because colchicine can affect any dividing cell by disrupting microtubules; its action is not strictly limited to mitotic cells, and it can interfere with meiotic divisions as well.