Abstract Detail


Mtileni, Masingitla [1], Glennon, Kelsey [1].

Examining broad geographic patterns of Rhodohypoxis baurii (Baker) Nel. var. platypetala Hilliard & Burtt cytotypes in the Drakensberg, South Africa.

The ecological and evolutionary dynamics of polyploidy (multiple sets of chromosomes) and cytotype ranges in natural populations affect the evolutionary trajectories of angiosperms. This study examined how environmental variables govern ploidy distributions in a Drakensberg near-endemic taxon, Rhodohypoxis baurii (Baker) Nel. var. platypetala Hilliard & Burtt. Preliminary findings identified diploids, triploids, and tetraploids in this taxon. Subsequently, the following questions were addressed: 1) are there mixed-ploidy populations? 2) do cytotypes occur in different geographic regions? and 3) are there unique environmental variables associated with each sampling site/cytotype population? In 2021, we visited ten natural populations of R. baurii var. platypetala across the KwaZulu-Natal and Free State mountain grasslands, South Africa, during the growing season. Flow cytometry data indicate that the populations were either diploid or tetraploid, but one mixed-ploidy population was identified. Additionally, diploid populations were found at higher altitudes than tetraploid populations. Climate data associated with each site indicate that there are some distinctions between the populations of different ploidies. This work contributes to the growing body of work that examines the role of ecological habitat differentiation between cytotypes that may explain any distribution patterns of cytotypes at geographic scales. Our findings suggest that polyploidy is a contributor factor of geographical distribution of this taxon.

1 - University Of The Witwatersrand, Animal, Plant & Environmental Sciences, Private Bag X3, Johannesburg, GT, WITS 2050, South Africa

Mountain grasslands endemic
Environmental distribution

Presentation Type: Oral Paper
Number: BIOG I013
Abstract ID:407
Candidate for Awards:None

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