In counting chromosome number and karyotype study, it is necessary to let chromosomes on metaphase by pretreatment before fixation. For this purpose, colchicine, or 8-oxyquinoline are generally used. The author found out that chromosomes could be scattered by illuminating cyanoferrate complex solution in which root-tips were sunk.
As materials, 8 sorts of plant such as Allium fisturosum, Allium tuberosum Rottler, Triticum vulgare were used. Their root-tips were sunk on the bottom of beaker in potassium ferricyanide solution 3×10exp(-4)M and illuminated through the solution ty sterilizing lamp for 1∼2 hours in dark room, keeping 10㎝ distance from light source to the surface of solution and 2㎝ depth of solution. Then again, they were illuminated to the light which was somewhat weaker intensity than the former(distance, 16㎝; depth, 3㎝) for 1.5∼2 hours after immersed in 1/100N-HCl and washed in water for each 5 minutes. By such methods chromosomes could be scattered. About the mechanism of scattering, it is supposed that CN and Fe(CN)_χ ions (χ≤5) which were gradually produced in the process of photodissociation acted together on the scattering of chromosomes.
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