White pine blister rust (WPBR) caused by the fungus Cronartium ribicola is a devastating introduced disease of five-needled pines (Section Strobus) and Ribes species in North America.

The impact of WPBR in Minnesota has hampered attempts to replant P. strobus in many high-hazard sites in the northeastern and north-central portions of the state. The development of resistant P. strobus seedlings will make planting P. strobus in Minnesota (and other areas of the Lake States, Northeastern US and Canada) more successful and will significantly improve current efforts to re-establish white pine throughout its original native range.

Our lab is focused on two main areas of white pine blister rust research:
1. Screening Pinus strobus seed sources for resistance to WPBR
2. Identifying resistance mechanisms/traits in resistant phenotypes

In conjunction with the Minnesota Tree Improvement Cooperative we are screening Eastern white pine seed sources (primarily from Minnesota) for resistance to WPBR. Several seed sources have been consistently resistant after artificial inoculations. One of these seed sources has recently been released for planting and is called Patton's Silver Splendor. This cultivar was named in recognition of Professor Robert Patton who carried out a great deal of early work on selecting white pines for resistance.

The seed sources identified as resistant by screening are also being used to identify resistance mechanisms/traits in needles and stems that may be used for future selection or breeding strategies. Using histology, scanning electron microscopy and biochemical analyses we are investigating potential mechanisms/traits that may contribute to resistance to white pine blister rust. Research findings indicate that multiple mechanisms may be present in resistant phenotypes.

Publications:

Jacobs, J.J., T. A. Burnes, A. J. David and R., A., Blanchette. 2009. Histopathology of primary needles and mortality associated with white pine blister rust in resistant and susceptible Pinus strobus. Forest Pathology 39:361-376. reprint

Burnes, T. A., R. A. Blanchette, J. A. Smith and J. J. Luby. 2008. Black currant clonal identity and white pine blister rust resistance. HortScience 43:200-202.reprint

Smith, J.A., Blanchette, R.A., Jacobs, J.J., Higgins, L., Witthun, B. A., Gillman, J. H. and A. J. David. 2006. Proteomic comparison of needles from blister rust-resistant and susceptible Pinus strobus seedlings reveals up-regulation of putative disease resistance proteins. Molecular Plant-Microbe Interactions 19: 150-160.reprint

Smith, J.A., Blanchette, R.A., Burnes, T.A., Gillman, J.H. and A. J. David. 2006. Epicuticular wax and white pine blister rust resistance in selections of Pinus strobus L. Phytopathology 96: 171-177. reprint

Jurgens, J.A., R.A. Blanchette, P.J. Zambino, and A. David. 2003. Histology of white pine blister rust in needles of resistant and susceptible eastern white pine. Plant Disease 87(9): 1026-1030. reprint

Smith, J. A. T. A. Burnes, J. A. Jurgens, A. J. David and R. A. Blanchette. 2003. Potential resistance mechanisms in Pinus strobus to Cronartium ribicola. In: Proceedings of the Second IUFRO Rusts of Forest Trees Working Party Conference, 19- 23 Aug., 2002, Xu, M.-Q., Walla, J.A., and Zhao, W.-X. (eds.) Yangling, China Forest Research 16 (Suppl). reprint

A white pine seed source we have found to be resistant to white pine blister rust, named 'Patton's Silver Splendor' has been released by the University of Minnesota and is available at many nurseries.

A native white pine growing in northern Minnesota being attacked by white pine blister rust

Seedlings of eastern white pine families in the greenhouse being used for inoculation studies to select resistant white pine to white pine blister rust