Cytological studies on two saprophytic orchid-species of Neottia asiatica Ohwi and Epipogium japonicum Makino

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Cytological studies on two species of saprophytic orchids were carried out. Neottia asiatica showed the resting chromosomes of the complex chromocenter type and the mitotic prophase chromosomes of early condensed segments located in their distal and interstitial regions. The species had the chromosome number of 2n=50 that was different from the previous count of 2n=36 by Sokolovskaya (1966). The chromosome complement at mitotic metaphase showed a gradual decrease in chromosome length from 5.1-1.4 μm. In contrast, Epipogium japonicum showed the resting chromosomes of the diffuse type and the mitotic prophase chromosomes of early condensed segments located in their proximal regions. The species had the chromosome number of 2n=78, counted here for the first time. The chromosome complement at mitotic metaphase showed a gradual decrease in chromosome length from 2.0-1.1 μm.