The analysis of genetic diversity of Cyperus papyrus L. using isoenzymes in Lake Victoria Basin, Kenya
Macharia, J.M. (2003). The analysis of genetic diversity of Cyperus papyrus L. using isoenzymes in Lake Victoria Basin, Kenya. MSc Thesis. Vrije Universiteit Brussel: Brussel. 79 pp.
Enzyme polymorphisms have been widely used in aquatic plant since the 1980s. In this study, an investigation of genetic diversity of Cyperus papyrus L. was done using isozymes. A total of 260 plants were analyzed from two lake populations, namely one the in Nyanza bay in the Lake Victoria basin of Kenya and a second in Lake Naivasha in the Rift Valley. Within these populations sites were considered as disturbed or putatively undisturbed. Six enzyme system, (POD, M E, Pest, SDH, GDH and GOT) under the same electrophoretic conditions were analyzed. The proportion of loci that were polymorphic showed an overall low level of genetic diversity among the populations. Allelic frequencies at SDH indicated that different alleles (A ,B , and C ) of the Cyperus papyrus L. were present in the Nyanza bay population while in Lake Naivasha only two alleles were present. The small papyrus population from K M F R I Pier (K PD ) had the highest heterozygosity observed (0.2917) while another small but severely disturbed papyrus population from Kibos (KD ) had the lowest (0.027). While comparing impacted and natural sites within the largest swamps, then the impacted tended to have a slightly higher heterozygosity than the natural, e.g. Usenge (disturbed=0.2069; undisturbed = 0.1892) and in Sondu (disturbed =0.1667; undisturbed =0.1384). Clonality was shown to be common in papyrus populations and the dominance o f a clone was higher in the presumed impacted sites of the larger swamps. The much smaller swamp area o f K M F R I pier and the highly impacted swamp of Kibos showed no such dominance of a particular clone and no obvious spatial genetic structure. The lowered gene diversity in Kibos could be the result of subsequent events of impacting (polluted floods, grazing, harvesting), whereas the higher gene diversity at KMFRI pier could indicated local recovery through sexual reproduction. This way, monitoring the genetic diversity in papyrus swamp could provide a novel method to estimate the health and status o f a population, such that priority swamp areas for conservation as well as for recovery could be assigned.
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