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ARS Home » Pacific West Area » Wapato, Washington » Temperate Tree Fruit and Vegetable Research » Research » Publications at this Location » Publication #379133

Research Project: Developing New Potatoes with Improved Quality, Disease Resistance, and Nutritional Content

Location: Temperate Tree Fruit and Vegetable Research

Title: Correlation and co-localization of QTL for stomatal density and canopy temperature under drought stress in Setaria

item PARTHIBAN, PRAKASH - University Of Illinois
item DARSHI, BANAN - University Of Illinois
item PAUL, RACHEL - University Of Illinois
item Feldman, Max
item BAXTER, IVAN - Danforth Plant Science Center
item XI, DAN - University Of Illinois
item FREYFOGLE, LUKE - University Of Illinois
item LEAKY, ANDREW - University Of Illinois

Submitted to: Journal of Experimental Botany
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/12/2021
Publication Date: 4/24/2021
Citation: Parthiban, P.T., Darshi, B., Paul, R.E., Feldman, M.J., Baxter, I., Xi, D., Freyfogle, L., Leaky, A.D. 2021. Correlation and co-localization of QTL for stomatal density and canopy temperature under drought stress in Setaria. Journal of Experimental Botany.

Interpretive Summary: Rainfed, annual grass crops like corn and sorghum comprise a large proportion of farm acreage in the midwestern United States. Farm expansion onto marginal lands and the predicted increases in both the frequency and severity of drought make developing drought resistant germplasm a national priority. Scientists at the USDA-ARS laboratory in Wapato, WA in collaboration with researchers at the University of Illinois (Urbana-Champaign) and at the Donald Danforth Plant Science Center measured stomatal patterning and leaf temperature in a Seteria biparental genetic mapping population. Surprisingly, leaf temperature exhibited a positive correlation with stomatal density. Both of these characteristics were negatively associated with plant size. Genetic mapping identified several genetic loci which contribute additively to influence these traits. Utilizing model systems to dissect the genetics of traits which have been difficult to study enhances our ability to predict plant performance and select the best performing progeny using molecular genetic markers

Technical Abstract: Mechanistic modeling indicates that stomatal conductance could be reduced to improve water use efficiency (WUE) in C4 crops. Genetic variation in stomatal density and canopy temperature was evaluated in the model C4 genus, Setaria. Recombinant inbred lines (RIL) derived from a Setaria italica x Setaria viridis cross were grown with ample or limiting water supply under field conditions in Illinois. An optical profilometer was used to rapidly assess stomatal patterning and canopy temperature was measured using infrared imaging. Stomatal density and canopy temperature were positively correlated but both were negatively correlated with total above-ground biomass. These trait relationships suggest a likely interaction between stomatal density and the other drivers of water use such as stomatal size and aperture. Multiple QTLs were identified for stomatal density and canopy temperature, including co-located QTLs on chromosomes 5 and 9. The direction of the additive effect of these QTLs on chromosome 5 and 9 were in accordance with the positive phenotypic relationship between these two traits. This suggests a common genetic architecture between stomatal patterning in the greenhouse and canopy transpiration in the field, while highlighting the potential of Seteria as a model to understand the physiology and genetics of WUE in C4 species