Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/5/2004
Publication Date: 7/15/2005
Citation: Bonman, J.M., Bockelman, H.E., Steffenson, B. and Jackson. L. 2005. Disease and insect resistance in cultivated barley accessions from the USDA National Small Grains Collection. Crop Sci. 45:1271-1280. Interpretive Summary: This paper represents the first synthesis of disease resistance data for the cultivated barleys from the National Small Grains Collection. It also represents the first effort to use modern Geographical Information Systems software to map accessions geographically and thus better understand the relationship between geographic origin and various disease and pest resistance traits. The results of our analysis will help NSGC better target future evaluation work and perhaps provide some specific guidance for future collection efforts. We also anticipate that publication of this work will increase the interest of plant breeders and geneticists in certain barley accessions, particularly those with multiple resistances.
Technical Abstract: Cultivated barley accessions (Hordeum vulgare subsp. vulgare L.) from the USDA Agricultural Research Service (ARS) National Small Grains Collection (NSGC) have been tested systematically for the past 20 years for disease and insect resistance. This study analyzed the resistance to barley yellow dwarf (BYD), spot blotch (SB), net blotch (NB), and stripe rust (SR) diseases and to Russian wheat aphid (RWA) with respect to 1) geographic origin of resistant accessions, 2) relationship to other NSGC descriptor data, and 3) relationships among resistances. 'Centers of concentration' for certain resistances were identified; Eastern Africa for several diseases, western Turkey and the Caucasus for SR resistance, Eastern Asia for adult plant resistance to NB, and South-central Asia for RWA resistance. SR was also associated with accessions originating from high altitude in Eastern Africa (Ethiopia). NB seedling resistance and SR resistance were associated with many grain characteristic descriptors, such as black aleurone and lemma; winter habit was positively associated with resistance to NB (seedling and adult plant), SB (adult plant), SR, and RWA and negatively associated with BYD resistance; landrace status was negatively associated with SB adult plant resistance and positively associated with SR resistance; and associations with the hulled character varied. A total of 48 accessions showed multiple resistance based on the field disease data and the RWA greenhouse data, including many with SR resistance as one component of the combination, many accessions from Ethiopia, and many accessions of unknown origin. SR testing at two locations, California and Bolivia, supported the conclusion that winter habit accessions were more resistant to the disease than were spring habit accessions. Information from this study will be used to guide future NSGC acquisition and evaluation efforts.