Genotypic‐specific response to exogenous applied salicylic acid in tall fescue under different irrigation conditions

Abstract

Salicylic acid (SA) is one of the endogenous plant growth regulators that play an important role in the regulation of plant growth and development in response to water deficit. Genotypic-specific response to exogenous applied SA in terms of physiological, enzymatic activity, and yield traits is poorly understood in tall fescue [Lolium arundinaceum (Schreb.) Wimm. syn. Festuca arundinacea Schreb.]. Twenty genotypes of tall fescue (selected from a broad germplasm) were assessed at field condition for morphological and physiological characteristics during 2016 and 2017 under three irrigation levels (normal, mild, and intense drought stress) in the presence of two SA concentrations (0 and 1 mM). Mild and intense drought stress conditions led to depression in photosynthetic pigments including chlorophyll a and b and total chlorophyll contents, plant height, crown diameter, and forage yield, despite increases in proline content, carotenoids, catalase, peroxidase, and ascorbate peroxidase activities.Application of SA decreased the adverse effects of drought stress by elevation of photosynthetic pigments and nonenzyme and enzymatic antioxidant activities and could enhance forage yield and drought tolerance in tall fescue genotypes. High genetic variation was observed among the genotypes in their response to the application of SA under drought stress conditions, and genotypes 3L and 1E were recognized as drought tolerant and stable genotypes for future breeding programs.

Variation in persistency, postdrought recovery and root characteristics in a tall fescue germplasm under interactive effects of exogenously applied salicylic acid and water stress

“…Drought is one of the important abiotic factors limiting the plant's growth by affecting morphological and physiological processes. However, certain cultural and chemical practices can reduce the negative effects of drought stress (IPCC, 2014; Pirnajmedin et al., 2020). Plant hormones are known as a strong and sustainable tool for reducing the adverse effects of live and nonpolluting stresses on plants.…”

“…The number of stems per plant (NS), plant height (PH), crown diameter (CD) and aboveground biomass (forage) on each plant was recorded following the method of Pirnajmedin et al. (2020). For measuring the aboveground biomass, in the middle of July, all plants were separately harvested at the same time.…”

“…Tall fescue is a cool‐season grass with high interest in the world since it has some characteristics conferring tolerance to water deficit and heat stress when compared to other cool‐season grasses (Gazanchian et al., 2006). Our previous study indicated that exogenously applied SA can ameliorate the negative effect of drought stress in terms of production and some physiological traits (Pirnajmedin et al., 2020). However, scientific data on the interactive effects of exogenous SA and water stress on postdrought recovery, root traits and PE are still rare in tall fescue.…”

Root Herbivory: Grass Species, Epichloë Endophytes and Moisture Status Make a Difference

“…A similar watering regime was applied in a second experiment to both tall fescue and meadow fescue infected respectively with E. coenophiala and E. uncinata , or endophyte-free. Because plant genotype is recognized as a factor in the physiological and biochemical responses of tall fescue/endophyte associations to drought [ 23 , 24 , 25 ], plant genotypes that were either endophyte-infected or endophyte-free in each trial were cloned across treatments. After 4–6 weeks of differing watering regimes, roots were harvested and fed to Costelytra giveni , an endemic New Zealand insect pest, in a bioassay over 7 days.…”