CYTOGENETIC STUDIES OF SOME SPECIES OF TRADESCANTIA (L) AND COMMELINA (L) IN AKWA IBOM STATE, NIGERIA

Morphological analyses of the vegetative characteristics of two species of Tradescantia and two species of Commelina grown in polythene bags in the greenhouse were done. Inter-specific variation in vegetative and floral morphology was significant (p<0.5). The root tips were harvested between 7:30 am and 9:00 am, pretreated in 8-hydroxyl-quinoline, and transferred into 3:1 ethanol acetic acid for 24 hours. Root tips were hydrolyzed in 10% hydrochloric acid and subsequently squashed in FLP orcein. The chromosome number was 2n = 12 in Tradescantia spathacea with a Karyotype formula of 10m + 2sm. The chromosome number of Tradescantia pallida was 2n = 24 with a Karyotype formula of 22m +2sm, while the Chromosome number was 2n = 22 in Commelina benghalensis with a karyotype formula of 14m+2sm + 4st. The chromosome number was 2n = 30 in Commelina diffusa with a karyotype formula of 28m + 2sm. The mean chromosome lengths in the two genera ranged from 1-4µm. A secondary construction satellite was observed in the longest chromosome of Commelina benghalensis. Morphological and cytological data from the two genera showed considerable differences, which would be helpful to the genera's taxonomic separation.