Karyomorphological studies on five species of Urochloa P.Beauv.(Poaceae).

Abstract

The karyotype morphology including chromosome length, centromere position, secondary constriction and asymmetry was analysed for five species of Urochloa. In general, the chromosomes were small, ranged between 0.76-1.90μm length and belonged to predominant ‘m’ types and less frequent ‘M’ and ‘sm’ types. Species with chromosome number 2n=28-U. mosambicensis, U. pullulans and U. trichopus were apparently similar in gross karyomorphology showing same karyotype asymmetry (2A) and comparable chromosome size and total chromosome length. In finer details, some recognisable differences were noticed between them. U. oligotricha with 18 pairs and U. panicoides var. panicoides with 24 pairs of chromosomes showed distinct karyotypes.