1a. Objectives (from AD-416)
Pulse crops including peas, lentils and chickpeas are some of the most nutritious crops in the human diet, having been grown in rotations with small grains for millennia. However, these pulse crops are also relatively low in several essential minerals. Iron and zinc deficiencies are prevalent where pulse crops are substantial dietary components. The ability of pulse crops to contribute to global dietary needs is also adversely impacted by a range of plant diseases, with the most destructive disease of chickpea being Ascochyta blight. The contributions of pulse crops to global human nutrition will be enhanced by developing new varieties that have high levels of disease resistance coupled with improved seed nutritional characteristics. Development of these improved varieties will be dependent on the identification of pulse lines that these desirable traits. The objectives of this study are to1) identify differences in seed protein and mineral content among varieties and advanced and preliminary pea, lentil and chickpea breeding lines of the USDA Grain Legume Genetics field breeding program; 2) determine the relative importance of genetic, environmental and genetic x environmental interaction effects on variability in seed protein and mineral content in these crops; 3) isolate toxins from the pathogen Ascochyta rabiei, and 4) develop a deteched leaf assay to identify chickpea lines with tolerance to Ascochyta blight.
1b. Approach (from AD-416)
Seed samples will be taken from the advanced pea, lentil and chickpea yield trials planted in the Spring of 2010. Peas and lentils will be grown at Kendrick, ID, Genesee, ID, Pullman, WA and Fairfield, WA. Chickpeas will be grown at Kendrick, ID, Genesee, ID, Pullman, WA and Colton, WA. Each advanced breeding line and commercial check will be grown in three 5 x 20ft2 replicated plots at each location. Samples from winter hardy pea and lentil breeding lines and cultivars will be obtained from advanced winter yield trials planted in the Fall of 2009 at three locations: Pullman, WA; Garfield, WA and Rosalia, WA. A total of 53 advanced pea breeding lines or cultivars, 51 advanced lentil breeding lines or cultivars and 12 advanced chickpea lines or cultivars will be examined. In addition, 13 preliminary pea breeding lines, 15 preliminary lentil lines, and 15 preliminary chickpea lines will be grown at Pullman, WA in three replicated plots and evaluated for protein and mineral content. Plots will be mechanically harvested and yields determined. Seed will be cleaned and 50 g samples will be collected from each plot for determinations of protein and mineral content. To determine the mineral content of each seed sample, seeds (with seed coats) will first be ground to a uniform powder. Two sub-samples from each plot will be wet digested and resuspended using trace metal-grade nitric acid and hydrogen peroxide. Two replicate digests will be analyzed for mineral concentration using inductively-coupled plasma atomic-emission spectroscopy (ICP-OES). This technique will provide analysis of K, P, Ca, Mg, Fe, Mn, Zn, Cu, Ni, and Mo. Seed protein concentrations will be derived based on seed nitrogen concentrations, which will be established using a LECO FP-528 Nitrogen/Protein Determinator.
3. Progress Report
Advanced pea, lentil, and chickpea breeding lines were grown in multiple locations in WA and ID and screened for seed content of 10 essential minerals. Significant differences were observed between breeding lines for quantities of all tested minerals and breeding lines were identified for each crop that had elevated levels of several minerals. These breeding lines are being used as parents for our breeding efforts focused on developing more nutritional pulse crops. The lead scientist monitors the Cooperator’s performance through regular phone conversations and email correspondence, visits to field locations during the growing season, and meetings held after the field season is completed.