Wheat Floret Development and the Relationship to Ear Temperature; the Interaction With Genotype, and Stress.

The use of thermal imaging is a valuable tool in the elucidation of thermal dynamics between a plant and its surrounding environment. Previously, studies have successfully investigated the spatial and temporal dynamics occurring in the wheat ear, as well as highlighting ways in which these may contribute to the development of a novel high-throughput screening tool for early generation selection of stress tolerant wheat lines. This work has however been limited to controlled environments and consequently further validation is needed in the field to be of direct value to breeders and physiologists. Therefore, a field scale study took place using six spring wheat (Triticum aestivum L.) genotypes of the elite recombinant inbred line Seri/Babax at CIMMYT in NW Mexico, during April and May 2013. Plants were grown under conditions of heat and drought stress in 0.8m x 2.0m blocks. Over the period of anthesis, Average Ear Temperature (AET) was recorded using a hand held infrared camera whilst the floret development stage of the ear was monitored. Infra red images and physiological data were gathered and correlated to grain yield. Additionally, a high-throughput Remote Sensing Platform (RSP) was utilized to conduct multi-spectral analysis to compare and contrast the six different genotypes. The RSP, based on both a helicopter and helium filled blimp, collected data which were used to calculate a range of physiological indices including canopy temperature, biomass, chlorophyll content and crop reflectance. Methodologies will be presented.