521 - Integrating cyber-physical system technology and mobile infrastructure to phenotype for high night-time temperature impact on field grown winter wheat

Although the average global daily maximum temperature is consistently warming, the minimum night temperature is increasing at a much quicker pace. High night-time temperature (HNT) stress coinciding with the grain-filling period is known to reduce grain yield and quality in cereals. An approach that would allow scientists to impose HNT stress on crops under field conditions involving a large diverse panel of genotypes and with the ability to maintain a dynamic temperature differential did not exist. For proof of concept, smaller-scale heat tents utilizing a custom cyber-physical system were constructed, which were able to maintain an average differential of 3.2 °C consistently at night compared to the outside ambient temperature throughout the grain-filling period. Biological data from 12 prominent genotypes confirmed the imposition of HNT stress through a significant reduction in yield, biomass, and 1000 grain weight.
In order to impose HNT stress on a large diversity panel of 320 accessions, the original experimental concept was adapted and expanded to a larger scale. Six movable heat tents measuring 30’ x 48’ were constructed which utilized a mechanical roll-up ventilation system in order to maintain an ambient daytime environment while still retaining the ability to impose a dynamic HNT stress.  The same set of 12 genotypes were included in the diversity panel with Everest as a check variety to validate the implementation and uniform distribution of HNT stress. Stress (+3.8 °C over ambient) was imposed after 95% of the accessions completed 100% flowering and maintained until physiological maturity. Half meter row lengths were harvested at physiological maturity and yield and yield components including harvest index, 1000 grain weight, and grain number were recorded. Agronomic responses across scales, changes on the grain physical dimensions and protein, starch and lipid composition visualized using laser scanning confocal microscopy in contrasting genotypes will be discussed.