Monday, November 5, 2007
52-1
Yield, Regrowth, Threshability and Mineral Concentration of Perennial Wheat in the Pacific Northwest.
Kevin M. Murphy1, Philip R. Reeves2, Julie Dawson1, and Stephen S. Jones1. (1) Dept Crop & Soil Science, Washington State University, 201 Johnson Hall, Pullman, WA 99164-6420, (2) Grand Forks Human Nutrition Research Center, USDA-ARS, 2420 2 Ave. N Stop 9034, Grand Forks, ND 58202-9034
The development of perennial wheat cultivars with acceptable yields and consistent regrowth introduces a potentially viable solution to the ecological problems of soil erosion and degradation, nutrient losses and associated riparian contamination in wheat based farming systems in the Pacific Northwest. Using classical plant breeding methods, genes from wild wheatgrass species that code for the perennial growth habit have been incorporated into high-yielding annual wheat cultivars. We evaluated 31 perennial hybrid breeding populations (derived from Thinopyrum elongatum/Chinese Spring//Madsen crosses) and two annual winter wheat lines for grain yield, regrowth, threshability, mineral nutrient concentration and several agronomic traits in three locations in Washington State in 2005 and 2006. We found significant variation among perennial populations for all traits studied. Genotype by location interactions were present for grain yield and threshability. Grain yield in the perennial populations ranged from 29 to 93% of the mean yield of the annual control cultivars. Regrowth after grain harvest was consistent among perennial lines at all locations. A threshability index (TI) was developed to evaluate populations for the presence of the tenacious glume trait. TI was 0.97 in the annual wheat cultivars and ranged from 0.62 to 0.89 in the perennial populations and was significantly different at all locations. Mineral nutrient concentrations in the perennial wheat lines were 46, 45, 31, 27, 38, 33 and 37% higher than annual wheat cultivars for calcium, copper, iron, magnesium, manganese, phosphorus, and zinc, respectively. No relationship existed between grain yield, regrowth and nutritional content among the perennial lines, indicating the potential for simultaneous selection of these traits. Our research suggests that selection for regrowth after harvest in perennial wheat populations has been moderately to highly successful. Selection priorities must now focus on improving yield, winter hardiness and threshability in perennial wheat populations.