Leaf shape in Begonia

The genetic basis of tropical diversity in Begonia

Working with the widespread tropical genus Begonia gives us a huge range of variation to study. We are producing a genetic map of Begonia which will allow us to see where in the genome the genes controlling particular aspects of form are found. We will be able to compare the organisation in Begonia to that in other species and find out how many genes control each trait and how strong the effects are. Comparisons of the links between traits and genes in the different Begonia species will help us understand how the very different forms have evolved. Comparisons between Begonia and model plants of temperate regions such as Arabidopsis and Antirrhinum will allow us to compare tropical and temperate evolution.

Diverse leaf shapes in Begonia


Some of the diverse leaf shape in BegoniaWe are focusing on natural variation in leaf shape. This is very variable between species and is thought to be part of a plant's adaptation to a particular environment. Geneticists using model species have been able to identify a number of genes that are involved in the development of a leaf. One group of genes, the KNOX genes are thought to be involved in making leaflets instead of a single leaf, and a second group of genes (ARP genes) may control where the leaf blade grows out from its stalk. Different species of Begonia have leaflets or single leaves and have leaf blade all around the leaf stalk (peltate, like nasturtiums) or just at the top (non-peltate, like an ordinary leaf). We are using genetics, sequence analysis and expression analysis to determine if KNOX and ARP genes control leaf shape in Begonia.

The species we are studying are mostly from section Gireoudia, a group of Central American/ Mexican begonias. These species are well delineated in the wild although wild hybrids have been reported and large numbers of horticultural hybrids have been produced. We are creating a multi-gene phylogeny to examine the evolutionary history of these species and studying the reproductive barriers that exist amongst them.


RBGE's Begonia groupRBGE's Begonia group visiting Glasgow Botanic Gardens' Begonia collections Spring 2007. Right to Left: Dr Mark Hughes, Daniel Thomas (Begonia systematics), Dr Catherine Kidner, Rhydian Beyon-Davies, Andrew Matthews, Fatima Dahmani, Clare Rickersby, Saima Umbreen (Begonia evo-devo)

People

Catherine Kidner - Group leader [The Kidner Lab]
Saima Umbreen - PhD student
Fatima Dahmani - MSc student 2007
Alex Twyford - Undergraduate Student 2007
Clare Rickersby - Undergraduate Student 2007
Andrew Matthews - Undergraduate Student 2007
Rhydian Beyon-Davies - Undergraduate Student 2007
Pierre Cattenoz - MSc student 2006
Jack Cavers- Undergraduate Student 2005

Publications

Catherine Kidner (2007b) Leaf evolution: working with what's to hand. Evolution and Development, in press

Catherine Kidner and Marja Timmermans (2007a) Mixing and matching pathways in leaf polarity. Curr Opp Pl. Sci 10:13-20

Sophie Neale, Will Goodall-Copestake and Catherine Kidner (2006) The Evolution of Diversity in Begonia. In: ‘Floriculture, Ornamental and Plant Biotechnology: Advances and Topical Issues'. J. A. Teixeira da Silva (Ed.) Global Science Books

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