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ARS Home » Pacific West Area » Pullman, Washington » Northwest Sustainable Agroecosystems Research » Research » Publications at this Location » Publication #286736

Title: Evaluation of winter wheat breeding lines for traits related to nitrogen use under organic management

Author
item DAWSON, J - Washington State University
item MURPHY, K - Washington State University
item Huggins, David
item JONES, S - Washington State University

Submitted to: Organic Agriculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/4/2011
Publication Date: 2/28/2011
Citation: Dawson, J.C., Murphy, K.M., Huggins, D.R., Jones, S.S. 2011. Evaluation of winter wheat breeding lines for traits related to nitrogen use under organic management. Organic Agriculture. 1:65–80.

Interpretive Summary: As production of organically-grown crops increases, interest in breeding crop cultivars specifically for organic agriculture is also increasing. This study evaluated 12 diverse winter wheat breeding lines chosen from conventional and organic breeding nurseries, six historic varieties and an experimental perennial wheat population under organic management in the Inland Pacific Northwest region of the USA. Significant genetic differences among wheat varieties were found for grain yield, grain percent nitrogen, grain total nitrogen, and aboveground biomass. We identified breeding lines with relatively high yield, acceptable grain protein, and stable performance over all four location–year combinations. These results will be useful for wheat breeders, and organic growers as wheat varieties breed under organic conditions will improve the performance of their crops.

Technical Abstract: There is growing interest in breeding crop cultivars specifically for organic agriculture, based on recognized differences in environmental and management conditions. This study evaluated 12 diverse winter wheat breeding lines chosen from conventional and organic breeding nurseries, six historic varieties and an experimental perennial wheat population under organic management in the Inland Pacific Northwest region of the USA. A randomized complete block design with three replications in two locations over 2 years was used. Based on an analysis of variance, significant genetic differences and crossover interactions across years were found for grain yield, grain percent nitrogen, grain total nitrogen, and aboveground biomass. There were no main effects of locations or location-by-genotype effects for these traits. Based on comparisons among these breeding lines, it appears that there is a possibility of selecting for performance across a limited ecological zone as top-yielding lines were the same in both locations. However, individual entries may have variable performance across years within a single location so selection for stability of performance over years is also necessary. Using an analysis of direct measures of grain yield and grain %N in each location–year combination and overall, we identified breeding lines with relatively high yield, acceptable grain protein, and stable performance over all four location–year combinations. The use of indirect measures or index selection to simultaneously select for grain yield and protein did not appear to be more effective than direct selection based on yield and grain %N measured under organic management.