Temperatures during colchicine immersion are varied from 5°C to 30°C, and the effects of temperature upon colchicine action are investigated in the
Allium test. The results are as follows:
1)C-tumour formation by colchicine is prominent in high temperature condition, but low temperature suppresses it completely.
2) As the temperature becomes high, the threshold concentration for mitotic disturbance declines.
3) As the temperature becomes high, the accumulation of mitoses becomes more prominent.
4) Immediately after 48 hours' immersion, colchicine induces mitoses of a polyploid nature only in a high temperature condition. But, after the lapse of 48 hours' replacement in water, mitosis completely disappears from these roots, while in the roots treated in the rather low temperature condition (15°C) normal mitoses of newly produced tetraploid nuclei are appearing in considerable frequencies.
5) The lowest temperature condition, 5°C, induces “reductional grouping” in very high frequency.
6) In the high temperature condition, the resting nuclei are severely injured, bringing about the diminution of vitality and complete disappearance of mitosis.
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