The genetic basis for natural variation in heteroblasty in Antirrhinum
Article first published online: 1 OCT 2012
© 2012 The Authors. New Phytologist © 2012 New Phytologist Trust
Volume 196, Issue 4, pages 1251–1259, December 2012
How to Cite
Costa, M. M. R., Yang, S., Critchley, J., Feng, X., Wilson, Y., Langlade, N., Copsey, L. and Hudson, A. (2012), The genetic basis for natural variation in heteroblasty in Antirrhinum. New Phytologist, 196: 1251–1259. doi: 10.1111/j.1469-8137.2012.04347.x
- Issue published online: 5 NOV 2012
- Article first published online: 1 OCT 2012
- Manuscript Accepted: 18 AUG 2012
- Manuscript Received: 28 MAY 2012
- BBSRC. Grant Number: BB/D522089/1
- Antirrhinum ;
- developmental constraints;
- quantitative trait loci (QTLs)
- Heteroblasty refers to the changes in leaf shape and size (allometry) along stems. Although evolutionary changes involving heteroblasty might contribute to leaf diversity, little is known of the extent to which heteroblasty differs between species or how it might relate to other aspects of allometry or other developmental transitions.
- Here, we develop a computational model that can quantify differences in leaf allometry between Antirrhinum (snapdragon) species, including variation in heteroblasty. It allows the underlying genes to be mapped in inter-species hybrids, and their effects to be studied in similar genetic backgrounds.
- Heteroblasty correlates with overall variation in leaf allometry, so species with smaller, rounder leaves produce their largest leaves earlier in development. This involves genes that affect both characters together and is exaggerated by additional genes with multiplicative effects on leaf size. A further heteroblasty gene also alters leaf spacing, but none affect other developmental transitions, including flowering.
- We suggest that differences in heteroblasty have co-evolved with overall leaf shape and size in Antirrhinum because these characters are constrained by common underlying genes. By contrast, heteroblasty is not correlated with other developmental transitions, with the exception of internode length, suggesting independent genetic control and evolution.