Soluble carbohydrates dynamics in wheat and rapeseed crops under shading, high temperature and its combination in post-flowering

RIVELLI, GONZALO M.; CALDERINI, DANIEL FERNANDO; ABELEDO, LEONOR GABRIELA; MIRALLES, DANIEL J.; RONDANINI, DEBORAH P

Rosario

Congreso; XXXIV Reunión Argentina de Fisiología Vegetal; 2023

SAFV

Stem soluble carbohydrates (CHS) in cereal and oilseed crops provide through remobilization an important source of assimilates during grain filling under abiotic stress conditions. However, little is known about the effects of combined abiotic stresses on the dynamics of wheat and rapeseed CHS. The aim of the work was to analyze the impact of the combined abiotic stress of high temperature and low incident radiation during the post-flowering period on the CHS dynamics of wheat and rapeseed. Field trials were conducted in a high (Valdivia, Chile; HYPE) and a low (Buenos Aires, Argentina; LYPE) yield potential environment, following a RCB design with 4 replicates. A spring wheat cultivar (Weebill) and a spring rapeseed hybrid (Solar CL) were evaluated. The treatments were: control (C), shading (S, -60% incident solar radiation), high temperature (HT, +5ºC during the midday hours) and combined stress of shading and high temperature (S+HT), using portable chambers placed in each plot during 10 days starting from 7 days after flowering in wheat and from 14 days after the start of flowering in rapeseed. In wheat, the concentration and content of CHS immediately after the stress were higher in the HYPE than in the LYPE for all treatments. The S (both environments) and S+HT (LYPE) treatments showed the lowest post-stress CHS concentrations in wheat. In rapeseed, the CHS concentration post-stress was contrasting between environments (7% higher in the HYPE than in the LYPE, average of all treatments). There were no differences in CHS concentration in rapeseed between treatments in any environment, while the CHS content only differed between S+HT and the control and S in the HYPE. In conclusion, the stress by shading (S and S+HT) provoked a significant reduction in the CHS concentration in wheat, in contrast to the greater stability observed in rapeseed.