PHENETIC INVESTIGATION OF NONNODULATING AFRICAN SPECIES OF ACACIA (LEGUMINOSAE) USING MORPHOLOGICAL AND MOLECULAR MARKERS

Morphological and RAPD markers were used to assess the relationships a mong nodulating and non-nodulating species of African Acacia. Non-nodu lating species of African Acacia are only found within subg. Aculeifer um sect. Monacanthea. African species of sect. Monacanthea examined we re found to form a group distinct from the other African species exami ned on a morphological and molecular basis. All lack the ability to no dulate, suggesting that non-nodulation may be used as a taxonomic tool . The species of sect. Aculeiferum were separated by RAPD and morpholo gical analysis into two groups depending on whether they were armed wi th prickles in pairs and/or prickles in threes, or solitary. A third g roup of species was identified within sect. Acacia: further subdivisio n of this group was achieved into subsectt. Pluriseriae and Uniseriae. The position of A. albida relative to other African Acacia species wa s found to be distinct but not totally independent of the genus. The p artitioning and distribution of the genetic variability within the gen us is further elucidated by the RAPD analysis of populations of Acacia species. A population analysis of A. polyacantha demonstrated geograp hical and site-specific variation.