Resilience of rapeseed to temperature increase during early grain filling in a high yielding environment

Abstract

Context

Global climate change is driving the temperature increase, which often reduces crop production. Most of the temperature increase studies in rapeseed have been conducted under controlled conditions, limiting their results to true field conditions.

Objective

This study aimed to assess the sensitivity of rapeseed to temperature increase during two phases of the early grain filling period in southern Chile, a high yield potential environment. To our knowledge, this is the first field study evaluating the effects of temperature increase at different phases after flowering in rapeseed.

Methods

Three field experiments were conducted with two adapted spring rapeseed hybrids, Lumen and Solar CL, under three temperature treatments: a control at ambient temperature, a 5°C increase from the beginning of flowering to 15 days after flowering (DAF), and the same temperature increase from 15 to 30 DAF.

Results

Grain yield was minimally affected by increased temperature in Lumen, but grain yield was sensitive to heating in Solar CL (up to −35.9 %) during the 0–15 DAF period. In this hybrid, grain number decreased 26.8 % in response to higher temperature. On the contrary, grain weight and grain oil concentration were tolerant to higher temperature and grain protein concentration was increased by heating.

Conclusions

The higher grain yield resilience of Lumen could be due to the longer period between start of flowering and physiological maturity (11 days, 173.6 °Cd) than Solar CL. The lower impact of heating on grain yield and yield components reported in the present study across the genotypes would be attributed to the lower background temperature of southern Chile than in other environments.