Effect of salinity and drought stress on germination and early seedlings growth of bread wheat (triticum aestivum l.)

Abstract

Salinity is one of the most important environmental stresses that limits soil fertility and has adverse effects on plant growth. In order to increase wheat production under saline conditions, it is necessary to better understand genotypic difference, the physiological and biochemical processes of salt tolerance in wheat. The aim of this study was to determine the most tolerant winter wheat varieties against salinity and osmotic stress at germination stage and early seedlings growth. The salinity and osmotic stress were simulated in controlled environmental conditions by adding different concentrations of NaCl and mannitol solution to the growing media of five winter wheat variety. In all studied varieties the benchmark water potential in which they had germinated and had a good seedlings growth was of -0.3MPa. Under the stronger stress, -0.6 MPa, all varieties showed reduction in the all examined parameters. The variety Bosanka, had the highest final germination and germination energy under both mannitol and salt stress treatments. The parameters defining the development or percentage of strong seeds, coleoptile and root length, fresh and dry weight of root and coleoptile of a seed were more affected by water deficit stress and salt stress than germination and germination energy. Biplot analysis showed that wheat cultivars grown under -0.6MPa osmotic had higher values of root/coleoptile ratio in relation to control and -0.3MPa treatment which is the most reliable for screening properties of the genotypes for drought resistance in seedling stage.