Heat shock tolerance mechanisms in wheat

Description of the topic

The negative effects of heat shocks (short periods of 1–4 consecutive days during which maximum temperature increases 2-4°C) on wheat yields during the grain-filling period are expected to become more common as a consequence of climate change. Heat shock can reduce grain weight and, sometimes, grain number, if it occurs before or soon after flowering, causing serious damage to wheat quality. Modeling studies by Asseng et al. (2011) suggested a yield reduction of ~0.2 t/ha for each such day, because of an assumed dramatic acceleration of leaf senescence in proportion to the number of such shocks. These effects should be influenced by the level of soil water and the previous acclimation of the wheat plants. The present study aims to identify physiological mechanisms associated with heat shock tolerance in a range of environments (drought, irrigation and heat) and the ability of different wheat genotypes to recover from brief 'heat shock' events.

Work expectations

The candidate will conduct research at CIMMYT’s experiment station in the Yaqui Valley (Northwest Mexico, Ciudad Obregon) during a period of 5 months (from February to June). The candidate will spend an additional month (July) at CIMMYT headquarters (in Texcoco) working with the data and statistical analysis for the publication.

During the period in Cd. Obregon, the candidate will work with the same genotypes under drought, irrigated and heat (late sowing) conditions. Two different heat shocks will be induced at heading stage and ten days after anthesis using specially designed tents in all three environments. Physiological characterization before, during and after heat shock will be conducted in the control and treated plots.

Required skills

The candidate should be able to work in the field under high temperature conditions (up to 40°C) and have basic knowledge of statistical analysis.