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:
This is the final report for this project that ended in July, 2013. This research relates to objective 1 of the inhouse project “Identify and select improved germplasm and cultivars for pea, lentil, and chickpea through systematic evaluation under biotic and abiotic stress conditions to identify tolerant or resistant types for release to stakeholders”. Nineteen advanced chickpea (café kabuli type) breeding lines and four chickpea cultivars were evaluated for yield and important agronomic traits at three locations in Washington and Idaho in 2011. Seed samples from each plot (3 plots per location for each entry) were harvested and cleaned. The seed samples are currently being evaluated for concentrations of 14 different minerals (Calcium, Potassium, Magnesium, Phosphorus, Sulfur, Boron, Cobalt, Iron, Manganese, Molybdenum, Sodium, Nickel, Selenium, and Zinc). Similarly, four green pea cultivars and 22 advanced green pea breeding lines were evaluated for yield and important agronomic traits at four locations in Washington and Idaho in 2011, and the seed concentrations of the 14 minerals are being determined. The same seed mineral concentrations are also being determined for over 50 lentil advanced breeding lines and cultivars grown at three locations in 2011. Although cool season food legumes can provide all essential minerals to the human diet, they have relatively low concentrations of several minerals including Iron, Magnesium, Selenium and Zinc. This study has identified pea and chickpea breeding lines with high levels of several minerals that are being used to develop improved varieties with superior nutritional qualities. Seed concentrations were also determined for 11 minerals from single samples collected for seven green pea cultivars, 19 advanced green pea breeding lines, four yellow pea cultivars and 14 advanced yellow pea breeding lines, which were grown at three locations in 2009. Mean seed concentrations between locations were significantly different for eight minerals (Calcium, Potassium, Magnesium, Phosphorus, Sulfur, Manganese, Selenium, and Zinc). Peas harvested from the Kendrick, Idaho, field site had the lowest mean seed concentrations of four minerals (Potassium, Magnesium, Phosphorus, and Manganese), and the highest concentrations of Selenium and Zinc. Green peas had significantly higher seed concentrations of Potassium, Magnesium, and Copper than yellow peas, while yellow peas had significantly higher seed concentrations of Cobalt. Seed mineral concentrations were also determined for single samples of 71 lentil breeding lines and cultivars, which were grown at two locations in 2009. The breeding lines represented the major market classes of lentils grown in the US, including Large Yellow (Laird and Richlea types), Turkish Red, Eston, Spanish Brown, Zero Tannin, and Winter-sown classes of lentils. In general, winter-sown lentils had high seed concentrations of all minerals except Potassium, Zinc, and Iron. Zero-tannin lentils had a significantly higher seed concentration of Magnesium than the other market classes. Turkish Red lentils had a significantly higher seed concentration of Copper than the other market classes. Significant differences in mean seed concentrations were observed among different lentil market classes for all minerals except iron.