In 25 taxa of Picea the somatic chromosomes were analyzed by a fluorescent banding technique using chromomycin A₃ (CMA) and DAPI. They had 2n=24 chromosome number and similar karyotypes among species. On metaphase chromosomes in each taxon the CMA-bands appeared at the interstitial and centromeric regions. DAPI-bands appeared on chromosomes of some species. The CMA-band pattern of each taxon was described after identification of most homologous chromosomes and compared among taxa. An alignment of species based on CMA-band pattern with some exception were coincident on their geographic distribution, and discussed on interspecific relationships, comparison to molecular phylogeny and DNA sequences corresponding to fluorescent bands.

View full abstract

Coix aquatica (2n = 10) is one of the three species of Coix L. occurring in Maharashtra. The detailed meiotic behavior, chromosome number, and pollen fertility were studied in three distantly located populations of Coix aquatica Roxb. The progeny has been studied as single plant cytology for three consecutive generations. All the three populations of the species had the diploid chromosome number of 2n = 10, and morphologically they were all alike except some minor differences like height of the plant, number of tillers, shape and size of seed. The plants of the population from Tuljapur (Dist. Oosmanabad) had narrow leaves and comparatively smaller conchate seeds. The behavior of their chromosomes during meiosis was normal in first two generations. While screening the third open pollinated generation, three plants from the Aundha-nagnath shown different chromosomal behavior though the chromosome number was same i.e. 2n = 10. It results in to various abnormalities like, univalents at diakinesis, precocious movement at metaphase, laggards and early segregation in to chromatids during anaphase I etc. Therefore, the plants has been deeply investigated for results at the end of meiosis-II, and it is presented in the present communication.

View full abstract

A karyomorphological study was made in Ledebouria crispa S.Venter (Asparagaceae). The chromosomes at resting stage were classified as the diffuse type, while those at mitotic prophase were classified as the continuous type. The chromosome number was 2n = 36 reported here for the first time. The 36 chromosome sets at mitotic metaphase showed gradual decrease in size from the longest to the shortest chromosomes and they showed symmetric karyotype due to arm ratio with 34m+2sm. Thus, the 18 pairs of chromosomes classified were comprised from two similar chromosomes and thus, it was concluded as a diploid.

View full abstract