Location: Plant Physiology and Genetics Research
Project Number: 5347-21000-011-09-T
Project Type: Trust
Start Date: Jan 1, 2011
End Date: Dec 31, 2012
The objectives of this study are to (i) advance and validate a tractor-based phenotyping method for canopy temperature, plant height, and vegetation indices (e.g., normalized difference vegetation index, NDVI), and (ii) conduct a time-related QTL analysis on these traits under supra-optimal temperatures and water-limited conditions.
In 2012, a genetic mapping population of 98 recombinant inbred lines (RILs), parents (NM24016 and TM1), and differential checks will be grown at Maricopa for a third consecutive year. Field evaluations at Maricopa will include well-watered and water-limited treatments with two replicates each. The water-limited treatment will be initially applied before first flower. Measurements of canopy temperature, plant height, and vegetation indices will be collected weekly from tractor-based observations throughout July-August, which coincides with the critical stage of peak flowering and boll development as well as the hot, humid monsoon season in central and western Arizona. These data will be compared to that of helicopter-based remote sensing of vegetation indices and land surface temperature, which is highly effective but expensive for remote sensing of crop fields. Other measured agronomic and physiological traits will include but are not limited to pollen sterility, specific leaf area, leaf thickness chlorophyll content, plant height, carbon isotope discrimination (an indirect measure of water use efficiency) as well as yield and fiber traits. Taken together, these data will be used in a time-related QTL analysis and analyzed together with phenotypic data from 2010 to test the role of physiological traits in cotton productivity under heat and water stress.