Seed Priming and Tolerance to Salt and Water Stress in Divergent Grain Sorghum Genotypes

Hellen Thayse Nascimento Araújo,Selma Freire de Brito,Jesimiel da Silva Viana,Sebastião Medeiros Filho,Charles Lobo Pinheiro,Marcos da Silva Maia

doi:10.4236/ajps.2018.94047

Abstract

Tolerance to water and salt stress during germination and growth of agricultural species might have superior results when seeds are submitted to priming processes. The objective of the present study was to evaluate the use of hydropriming and hormonal priming with gibberellic acid (GA3) on the tolerance of divergent genotypes of sorghum to salt and water stress during germination and seedling growth. The genotypes analyzed were cultivar BRS 330 and lineage 201420, which are the most and least tolerant to water and salt stress, respectively. Sowing was undertaken under control (no stress), water stress (-0.6 MPa), and salt stress (20 dS·m-1) conditions, and the seeds were subjected to the following treatments: control-no immersion; hydropriming-immersion for 2 hours in distilled water; and hormonal priming-immersion in GA3 solutions, at concentrations of 50, 75, and 100 ppm, for 2 hours. After soaking, the seeds were dried for 24 hours at a temperature of 30°C ± 2°C. The variables analyzed were percentage and germination speed index, root and shoot lengths, and root/shoot ratio. The stress conditions analyzed negatively affected the two genotypes; however, the seeds that underwent priming processes improved the performance of the genotypes under salt and water stress conditions, especially when using seeds of the more tolerant genotype (BRS 330) subjected to hormonal priming at 100 ppm GA3 concentration.

Highlights

The objective of the present study was to evaluate the use of hydropriming and hormonal priming with gibberellic acid (GA3) on the tolerance of divergent genotypes of sorghum to salt and water stress during germination and seedling growth
Sowing was undertaken under control, water stress (−0.6 MPa), and salt stress (20 dS·m−1) conditions, and the seeds were subjected to the following treatments: control-no immersion; hydropriming-immersion for 2 hours in distilled water; and hormonal priming-immersion in GA3 solutions, at concentrations of 50, 75, and 100 ppm, for 2 hours
The stress conditions analyzed negatively affected the two genotypes; the seeds that underwent priming processes improved the performance of the genotypes under salt and water stress conditions, especially when using seeds of the more tolerant genotype (BRS 330) subjected to hormonal priming at 100 ppm GA3 concentration

Summary

Introduction

It is very versatile and is included in the production of human and animal food, as well as alcohol and industrial products [2] Cultivation of this crop is centered in tropical and subtropical regions, primarily in marginal areas that are more stress-prone [3]. The effects of environmental restrictions on plants have received increasing attention due to the potential impacts of climate change [6], which might hinder the maintenance of, and increase in, agricultural productivity, especially in arid and semi-arid regions [7] This is due to agricultural losses related to increases in salinity and drought, which are some of the main abiotic limiting factors in these regions [6]. These conditions might cause stress that influences the entire plant, causing damage to all major plant processes, including germination, photosynthesis, water and nutrient absorption, or even causing death of the plant [8]

Objectives

Methods

Results