Is variation in susceptibility to Phytophthora ramorum correlated with population genetic structure in coast live oak (Quercus agrifolia)?
Article first published online: 2 SEP 2004
Volume 165, Issue 1, pages 203–214, January 2005
How to Cite
Dodd, R. S., Hüberli, D., Douhovnikoff, V., Harnik, T. Y., Afzal-Rafii, Z. and Garbelotto, M. (2005), Is variation in susceptibility to Phytophthora ramorum correlated with population genetic structure in coast live oak (Quercus agrifolia)?. New Phytologist, 165: 203–214. doi: 10.1111/j.1469-8137.2004.01200.x
- Issue published online: 2 SEP 2004
- Article first published online: 2 SEP 2004
- Received: 12 May 2004 Accepted: 5 July 2004
- amplified fragment length polymorphism (AFLP);
- disease susceptibility;
- molecular marker;
- Phytophthora ramorum;
- population structure;
- Quercus agrifolia
- • California coastal woodlands are suffering severe disease and mortality as a result of infection from Phytophthora ramorum. Quercus agrifolia is one of the major woodland species at risk. This study investigated within- and among-population variation in host susceptibility to inoculation with P. ramorum and compared this with population genetic structure using molecular markers.
- • Susceptibility was assessed using a branch-cutting inoculation test. Trees were selected from seven natural populations in California. Amplified fragment length polymorphism molecular markers were analysed for all trees used in the trials.
- • Lesion sizes varied quantitatively among individuals within populations, with up to an eightfold difference. There was little support for population differences in susceptibility. Molecular structure also showed a strong within-population, and weaker among-population, pattern of variation.
- • Our data suggest that susceptibility of Q. agrifolia to P. ramorum is variable and is under the control of several gene loci. This variation exists within populations, so that less susceptible local genotypes may provide the gene pool for regeneration of woodlands where mortality is high.