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United States Department of Agriculture

Agricultural Research Service

Research Project: REDUCING SOYBEAN YIELD LOSSES THROUGH GENETIC IMPROVEMENT

Location: Crop Genetics Research Unit

Title: Determination of moisture deficit and heat stress tolerance in corn using physiological measurements and a low-cost microcontroller-based monitoring system

Authors
item Kebede, Hirut
item Fisher, Daniel
item Young, Lawrence

Submitted to: Journal of Agronomy and Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 8, 2011
Publication Date: October 24, 2011
Citation: Kebede, H.A., Fisher, D.K., Young, L.D. 2011. Determination of moisture deficit and heat stress tolerance in corn using physiological measurements and a low-cost microcontroller-based monitoring system. Journal of Agronomy and Crop Science. 198:118-129.

Interpretive Summary: Moisture deficit accompanied by high temperature are the major environmental stress factors that affect corn production in the southern United States. In the Mid-South, corn plants frequently encounter a period of drought and heat stress during flowering and kernel development. In order to evaluate crop plants for environmental stress tolerance, we need to monitor changes in their physical environment under natural conditions, especially when there are multiple stress factors, and integrate this information with physiological responses. A low-cost microcontroller-based system was developed to continuously measure and record canopy, soil and air temperatures, and soil moisture status in cropped fields, which among other factors, affect plant and soil water relations. Continuous data collection is advantageous, particularly in monitoring canopy temperature (a parameter often used to assess plant stress caused by moisture deficit or high temperature), which is subject to rapid fluctuations over the course of a day, and the associated factors such as air temperature. A field experiment was conducted at the Jamie Whitten Delta States Research Center, Stoneville, MS, in 2009 and 2010 to examine how this system, in combination with physiological measurements, could assist in detecting differences among corn genotypes for drought and heat stress tolerance. Variations observed in air and soil temperature, and soil moisture in plots of five corn genotypes under irrigated and non-irrigated conditions helped explain the difference in canopy temperature among the genotypes. These differences were reflected in measurements on four stress related physiological traits. These results demonstrated that data from the low-cost microcontroller-based system, in combination with physiological measurements, was effective in evaluating the corn genotypes for drought and heat stress tolerance.

Technical Abstract: In the southern United States, corn production encounters moisture deficit coupled with high temperature stress, particularly during the reproductive stage of the plant. In evaluating plants for environmental stress tolerance, it is important to monitor changes in their physical environment under natural conditions, especially when there are multiple stress factors, and integrate this information with their physiological responses. A low-cost microcontroller-based system was developed to automate measurement of canopy, soil and air temperatures, and soil moisture status in field plots. The purpose of the present study was to examine how this system, in combination with physiological measurements, could assist in detecting genotypic differences among corn lines in response to moisture deficit and heat stress. Three commercial hybrids and two inbred germplasm lines were grown in the field under irrigated and non-irrigated conditions. Leaf water potential, photosynthetic pigments, cell membrane thermostability (CMT), and maximum quantum efficiency of PSII (Fv/Fm) were determined on these genotypes under field and greenhouse conditions. Variations observed in air and soil temperatures, and soil moisture in plots of the individual corn genotypes helped explain the genotypic differences in canopy temperature (CT), and these variations were reflected in the physiological responses. One of the commercial hybrids, having the lowest CT and the highest CMT, was the most tolerant among the genotypes under moisture deficit and heat stress conditions. These results demonstrated that the low-cost microcontroller-based system, in combination with physiological measurements, was effective in evaluating corn genotypes for drought and heat stress tolerance.

Last Modified: 7/28/2014
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