Suitable rootstocks can alleviate the effects of heat stress on pepper plants

Abstract

[EN] In this study, different pepper rootstocks are tested for their ability to overcome heat stress situations. This work aims to evaluate: (i) the physiological mechanisms that occur during long heat stress periods (7 days) under controlled conditions in a pepper variety grafted onto accessions; (ii) the heat stress behaviour of these grafted pepper plants under greenhouse conditions in terms of marketable yields. For this purpose, plants of Lamuyo-type sweet pepper `Herminio F1¿ (VA), grafted onto six accessions (VA/A25, VA/A31, VA/A34, VA/A52, VA/A57, VA/A6), and a self-grafted variety (VA/VA) were grown under controlled conditions in growth chambers (28/24 °C, day/night temperatures and 38/24 °C for control and heat stress, respectively) and under greenhouse conditions (38/24 °C). For the controlled conditions, relative growth rate, leaf area, electrolyte leakage, chlorophyll a fluorescence and heat shock proteins were determined. For the greenhouse conditions, fresh and dry weigh, electrolyte leakage and fruit yield were determined. Our results confirmed that grafting a pepper cultivar onto appropriate rootstocks such as A6, A25 and A57 can overcome the negative effects of heat stress conditions with a higher relative growth rate, leaf area and Fv/Fm, and lower electrolyte leakage under the controlled conditions, and with higher marketable yields under the greenhouse conditions.