DNA barcodes reveal microevolutionary signals in fire response trait in two legume genera.
Large-scale DNA barcoding provides a new technique for species identification and evaluation of relationships across various levels (populations and species) and may reveal fundamental processes in recently diverged species. Here, we analysed DNA sequence variation in the recently diverged legumes from the Psoraleeae (Fabaceae) occurring in the Cape Floristic Region (CFR) of southern Africa to test the utility of DNA barcodes in species identification and discrimination. We further explored the phylogenetic signal on fire response trait (reseeding and resprouting) at species and generic levels. We showed that Psoraleoid legumes of the CFR exhibit a barcoding gap yielding the combination of matK and rbcLa (matK + rbcLa) data set as a better barcode than single regions. We found a high score (100 %) of correct identification of individuals to their respective genera but a very low score (<50 %) in identifying them to species. We found a considerable match (54 %) between genetic species and morphologically delimited species. We also found that different lineages showed a weak but significant phylogenetic conservatism in their response to fire as reseeders or resprouters, with more clustering of resprouters than would be expected by chance. These novel microevolutionary patterns might be acting continuously over time to produce multi-scale regularities of biodiversity. This study provides the first insight into the DNA barcoding campaign of land plants in species identification and detection of the phylogenetic signal in recently diverged lineages of the CFR.
Bolus Herbarium, Biological Sciences Department, University of Cape Town, Private Bag X3, Rondebosch 7700, South Africa bllabu001@myuct.ac.za.
Abubakar
A
Bello
Department of Plant Science, University of Pretoria, Private Bag X20, Hatfield 0028, Pretoria, South Africa.
Barnabas H
BH
Daru
Bolus Herbarium, Biological Sciences Department, University of Cape Town, Private Bag X3, Rondebosch 7700, South Africa.
Charles H
CH
Stirton
Bolus Herbarium, Biological Sciences Department, University of Cape Town, Private Bag X3, Rondebosch 7700, South Africa.
Samson B M
SB
Chimphango
African Centre for DNA Barcoding, Department of Botany and Plant Biotechnology, University of Johannesburg, PO Box 524, Auckland Park 2006, Johannesburg, South Africa.
Michelle
M
van der Bank
African Centre for DNA Barcoding, Department of Botany and Plant Biotechnology, University of Johannesburg, PO Box 524, Auckland Park 2006, Johannesburg, South Africa.
Olivier
O
Maurin
Bolus Herbarium, Biological Sciences Department, University of Cape Town, Private Bag X3, Rondebosch 7700, South Africa.
A Muthama
AM
Muasya
Fabaceae; Otholobium; Psoralea; South Africa; reseeders; resprouters