Cytological studies in two species of Epipogium, myco-heterotrophic orchids, were carried out. Epipogium roseum had the chromosome number of 2n=ca.70, 2n=35_II and n=35, that was different from the previous count of 2n=68 (Singh 1983). The chromosome complement at resting stage showed the complex chromocenter type, and the metaphase II chromosomes in meiosis showed a gradual decrease in chromosome length from 1.7-0.7μm. Epipogium aphyllum had the chromosome number of 2n=72, 2n=36_II and n=36, that was different from the previous counts of n=34 (Francini 1930, Afzelius 1954) and 2n=68 (Gurzenkov 1973, Uhrikova and Majovsky 1980). The chromosome complement at resting stage showed the complex chromocenter type and the metaphase II chromosomes in meiosis showed a bimodal karyotype in length consisted of three large chromosomes varied from 6.5-4.2μm and 33 small chromosomes varied from 2.1-1.4μm. Compared with the karyotype of E. japonicum (2n=78) reported by the author (2008), three species of Epipogium were different in chromosome number and length and karyotypes at resting stage and metaphase chromosomes from each other. Though, if it was thought that the one large chromosome of E. aphyllum was derived from the fusion of two small chromosomes of E. japonicum, the chromosome complements of both species were more closely allied than that of E. roseum.

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A karyomorphological characterization of Polytrias amaura (Poaceae) was performed using orcein staining, sequential fluorescent staining with chromomycin A₃ (CMA) and 4',6-diamidino-2-phenylindole (DAPI), and fluorescence in situ hybridization (FISH) method. The common somatic complement with 20 chromosomes were observed in all metaphase cells analyzed. Mitotic chromosomes in respective chromosome complement showed a gradual decrease in size from the largest to the smallest chromosomes. The largest and the smallest chromosome lengths at metaphase were 3.5 μm and 2.0 μm, respectively. The fluorochromes of CMA and DAPI gave reproducible condensation pattern to every prometaphase chromosome, but not metaphse. Each chromosome displayed a characteristic condensation pattern, which was quite same between differential staining methods of GC-specific CMA and AT-specific DAPI. In FISH, two bright 5S rDNA signals were detected at interstitial region of the chromosomes.

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At present, cytological evaluation has been done on population basis of nine species belonging to six genera of family Poaceae from district Kangra of Himachal Pradesh, a hilly state of Western Himalayas. On the basis of world-wide data, the chromosome number counts have been made for the first time for three species such as Agrostis debilis (n=14), Poa nepalensis (n=14) and P. setulosa (n=14); variable chromosome number reports for Eleusine indica (n=14) and higher frequency of B-chromosomes in Poa annua (n=14+0-3B). Likewise, for information on reports from India, four species such as Piptatherum microcarpum (n=12), Rottboellia exaltata (n=30), Setaria barbata (n=18) and Setaria megaphylla (n=18) have been cytologically worked out for the first time.

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The occurrence of polytenic nuclei in the anther tapetum of field grown variety K 5269 of a bean species, Vigna unguiculata has been recorded. There are pronounced polytene nuclei with chromocenters unassociated with chromatin bundles. In comparison to polytenic nuclei of other plants they were relatively smaller with a small nucleolus. These features of polytenic nuclei suggest low level of endoreduplication in Vigna unguiculata.

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