Abstract Detail

Conservation Biology

Jensen, Helen [1], Dreiseitl, Antonin [2], Sadiki, Mohammed [3], Schoen, Daniel J. [1].

The evolution of pathogen resistance in traditional varieties of barley (Hordeum vulgare) conserved on-farm versus in seed bank collections.

Traditional varieties of crop plants are often conserved in seed banks (ex situ conservation). It may, however, be preferable to conserve them in their native environment (in situ conservation), to ensure continued adaptation to evolving pathogen virulence. We tested if collections of a traditional variety of barley (Hordeum vulgare ssp. vulgare) collected in Morocco and conserved ex situ for 23 years show a decline in resistance to an endemic fungal foliar pathogen, Blumeria graminis f.sp.hordei (Bgh), compared with in situ collections that have been continuously cultivated in the region. We measured the qualitative and quantitative resistance to Bgh of these collections using detached leaf assays and field trials. Ex situ collections did not show a significant decline in qualitative resistance to eight specific isolates of powdery mildew, compared to in situ collections. In field trials, however, where plants were exposed to naturally occurring powdery mildew inocula, there were both increases and decreases in quantitative resistance in ex situ versus in situ collections. Overall, in this study system, in situ conservation resulted in both adaptive and maladaptive changes in the quantitative resistance of the crop germplasm, depending on the collection tested. This challenges the assumption that in situ conservation consistently results in improved adaptation to pathogen virulence and suggests a more complex scenario, consistent with examples of plant-pathogen co-evolution in wild systems. We discuss these findings with regards to resistance evolution and crop germplasm conservation.

Broader Impacts:

1 - McGill University, Department of Biology, 1205 Dr. Penfield Avenue, Montreal, QC, H3A 1B1, Canada
2 - Agricultural Research Institute Kromeriz, Department of Plant Protection, 2787 Havlickova, Kromeriz, 76701, Czech Republic
3 - Institut Agronomique et Vétérinaire Hassan II, Département d’Agronomie et d’Amélioration des Plantes, B.P. 6202 Rabat-Instituts, Rabat, Morocco

Keywords:
plant genetic resources
conservation
adaptation
resistance
pathogen
Hordeum vulgare
Blumeria graminis.

Presentation Type: Oral Paper:Papers for Topics
Session: 48
Location: Waterman Room/Chase Park Plaza
Date: Wednesday, July 13th, 2011
Time: 1:30 PM
Number: 48001
Abstract ID:93