Field-grown soybean shows genotypic variation in physiological and seed composition responses to heat stress during seed development

An average temperature increase between 2.6 and 4.8 °C, along with more frequent extreme temperatures, will challenge crop productivity by the end of century. To investigate genotypic variation in soybean response to elevated temperature, six (Glycine max) genotypes were subjected air + 4.5 °C above ambient for 28 days open-top field chambers. Gas exchange chlorophyll fluorescence measured before during heating yield as well seed composition evaluated at maturity. Results show that long-term increased nighttime respiration, maximum velocity carboxylation Rubisco, impacted protein concentration, reduced oil concentration across genotypes. The this study varied responses photosynthetic CO2 assimilation, stomatal conductance, photosystem II operating efficiency, quantum efficiency These diverse among development field, reveal potential heat tolerance be improved through breeding underlines importance identifying efficient selection strategies stress-tolerant crops.