Amelioration of high temperature stress by exogenously applied salicylic acid: Genotype‐specific response of physiological traits

Abstract

In arid and semi-arid regions of the world, high temperature stress adversely affects growth and development of cool-season grasses during late spring and summer. Salicylic acid (SA) is one of the endogenous plant growth regulators that plays an important role in the regulation of plant growth and development in response to high temperature stress. The aim of the present study was to assess the effectiveness of SA in alleviating the negative effects of high temperature during the summer in different tall fescue (Festuca arundinacea Schreb.) genotypes under field conditions. Twenty genotypes of tall fescue (selected from a broad native and exotic germplasm) were assessed at field condition for morphological and physiological characteristics during 2016 and 2017 under normal irrigation in the presence of two SA concentrations (0 and 1 mM). High temperature during the summer led to induction of incomplete summer dormancy and depression in summer forage yield. Application of SA decreased the adverse effects of high temperature stress by elevation of photosynthetic pigments, proline accumulation, and increasing nonenzyme and enzymatic antioxidant activities, and could therefore be used to enhance forage yield and heat tolerance in tall fescue genotypes. The genotypes exhibited obvious differences in their response to SA application under the semiarid climate conditions of central Iran. Among the studied genotypes, 3L and 1E were recognized as heat tolerant and stable genotypes that would be preferable for regions with high temperature.

Genetic parameters and selection in full-sib families of tall fescue using best linear unbiased prediction (BLUP) analysis

“…In both parental genotypes and full-sib families of tall fescue, summer dry forage yield (SUDFY) was found to be lower than spring (SPDFY) and autumn dry forage yield (AUDFY) during the years of experiment. Consistent with our finding, several researchers have reported the reduction of summer forage yield in some grass species such as tall fescue which is likely due to the higher temperature and induction of summer dormancy [ 31 – 33 ]. Kallida et al [ 34 ] indicated that perennial grass species with summer dormancy have less yield production and growth during summer seasons than during spring and autumn seasons despite irrigation, and they have a better opportunity to survive and recover through periods of extended hot and dry conditions.…”

Genetic Parameters and Selection in Full-Sib Families of Tall Fescue Using Best Linear Unbiased Prediction (BLUP) Analysis of Animal Breeding and Genetic

“…In both parental genotypes and full-sib families of tall fescue, summer dry forage yield (SUDFY) was found to be lower than spring (SPDFY) and autumn dry forage yield (AUDFY) during the years of experiment. Consistent with our nding, several researchers have reported the reduction of summer forage yield in some grass species such as tall fescue which is likely due to the higher temperature and induction of summer dormancy [31][32][33]. Kallida et al [34] indicated that perennial grass species with summer dormancy have less yield production and growth during summer seasons than during spring and autumn seasons despite irrigation, and they have a better opportunity to survive and recover through periods of extended hot and dry conditions.…”