Germination screen of eco-extracts from soil cyanobacteria and microalgae for their biostimulant effects on wheat seeds emergence and vigor

Abstract

Global production of cereals especially wheat is faced with ever-growing demand. Major efforts are directed towards enhancing productivity of wheat through utilization of chemical fertilizers at different growth stage. However, less attention has been devoted to seed concerns such as uniformity and vigor for more successful seed establishment and therefore less use of chemical fertilizers. Among a plethora of solutions addressing seed germination performance, biostimulants represent a valid and sustainable solution to enhance germination and vigor. Within biostimulants, microalgae- and Cyanobacteria-based biostimulants proved their utility as seed germination enhancers. The objective of this study was to screen the biostimulant effects of eco-extracts prepared from soil-isolated Cyanobacteria and microalgae on wheat seed germination. The effects of wheat seed soaking with two concentrations (0.1 and 1 g/L) of ten different eco-extracts were investigated via evaluating different germination indices as well as biometric parameters. Results of biochemical analysis of the eco-extracts indicated important amounts of bioactive molecules, mainly indole-3-acetic-acid (IAA) and polyphenols. Significant enhancements in germination indices as well as coleoptile and radicle length were observed in both microalgae- and Cyanobacteria-based eco-extracts applications, with no recorded phytoinhibitory effects. Principal component analysis revealed higher associations of treatments at low concentration (0.1 g/L) with positive enhancements in germination, vigor, and biometric parameters. These findings highlighted first and foremost the biostimulant activity of soil isolated microalgae and Cyanobacteria as seed treatments, as well as the utility of eco-extracts as sustainable tools for enhancing seed germination and vigor.