～おしつぶし法～の改良法による茶樹の体細胞染色体に関する研究

抄録

The materials used for the preparation are the rapidly growing young leaf tips, one mm in length. (Fig. 1).
Procedure of a modified squash method applied to this investigation is as follows:
(1) Maceration in 1.2N HCl for 15 min.
(2) Rinse in water, about 30 sec.
(3) Immerse in chromo-acetic mixture(CrO₃: lg., glacial acetic acid : 3cc., distilled water: 100 cc.) for 15 sec.
(4) Rinse in water, about 30 sec.
(5) Immerse in ammonia alcohol (30% alcohol: 100 cc., ammonia 5-6 drops) for 15 sec.
(6) Rinse in water, about 30 sec.
(7) Place the material on slide and then drop aceto-carmine (45% acetic acid, 1.5g carmine) over it.
(8) Place cover glass in position, and apply firm pressure to squash.
(9) Press slightly on cover glass again.
Leaf tip cell in tea plant resisted to crushing when treated simply with the aceto-carmines “Leaf smear method.” By this method, cells could be squashed flat easily and separation of chromosomes could be obtained.
In Thea sinensis L. each of the metaphase chromosomes in the leaves was about 1.5-4μ in length. With regard to the chromosome types, metacentric chromosomes and subcentric chromosomes were observed. Diploid plants, were constantly found to have 15 pairs of chromosomes. Photomicrographs of the chromosomes of two varieties of Thea sinensis are shown in Fig. 2.