Location: Adaptive Cropping Systems Laboratory2017 Annual Report
1. Screening soybean for drought tolerance. Recent USDA ARS research indicates that screening soybean lines for drought resistance using carbon isotope discrimination or mesophyll conductance is problematic. Rather, direct measurements of water use applied to existing genetic variation will be needed in order to select for drought tolerance.
2. Rising carbon dioxide and rice nutrition. Working with researchers in China and Japan, USDA-ARS scientists demonstrated that the nutritional integrity (protein, vitamins and micro-nutrients) of a genetically diverse set of rice lines, including Japonica, Indica and hybrids were negatively impacted by carbon dioxide concentrations likely to occur this century. These data, when applied to the ten countries that consume the most rice as part of their daily caloric supply, indicate that the health impacts of increasing atmospheric CO2 on nutritional deficits may be substantial, especially for poor populations who depend on rice as their primary food source.
3. Climate change and potato metabolites. Water stress effects were evaluated as a function of current and projected carbon dioxide for two varieties of potato that differed in drought tolerance. Leaf metabolites, important to leaf chemistry and plant survival, differed not only as a function of drought, but also in response to future carbon dioxide levels. These data suggest that sufficient variation among potato lines could be used to develop potatoes that are better adapted to future climates.
4. CO2 impacts on flowering time affect yield responses in soybeans. There has been an extensive search for plant traits which affect how much crop yields increase at elevated carbon dioxide concentrations. Identification of such traits would aid in adapting crops to future climates. Research at the Beltsville Agricultural Research Center (BARC) has found that cultivars even within the same Maturity Group differ in the extent to which elevated carbon dioxide delays the transition from vegetative to reproductive growth in soybean. A later transition time allows more main stem pods to develop, and increases the stimulation in yield.
5. Rising CO2 can alter peanut quality and increase allergen content. Peanut varieties were compared to determine the basis for the variation in growth and yield in response to rising CO2 levels. Yield for "Virginia Jumbo" showed a consistently greater increase relative to "Georgia Green" in response to elevated CO2. Also resulted in a significant increase in the concentration of Ara h 1, a known peanut allergen Ara h 1. While selection for CO2 response is a valuable trait for increasing economic production, food safety concerns should also be considered in future peanut breeding.
6. Future climates may negatively affect soybean seed quality. Soybean plants were grown at low (22/18ºC), optimal (28/24ºC) and high (36/32ºC) growth temperatures. Fifty one seed quality components were measured at four time points during maturation. About 80% of seed components were abundant in young seeds and decreased to very low levels in mature seeds. Air temperature and CO2 enrichment affected conditions developing soybean seeds. These environmental treatments mostly affected components of young soybean seeds. Elevated growth temperatures increased shikimate, pinitol and oleate levels in mature seeds.
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