Abiotic stress tolerance in barley

Abstract

Barley (Hordeum vulgare L.) is one of the primitive and oldest domesticated cereals and preferred by gladiators due to its nutritional properties. Primarily this crop is used for feed and food purposes, whereas its enzymatic and husk properties make it unique for malting and brewing purposes. Barley is known to be a climate resilient crop and can thrive well under adverse conditions of cultivation. In some regions of the world, where winter crops like wheat are difficult to be grown or their cultivation is uneconomical due to the harsh climatic conditions and/or problematic soils, barley is the only option to sustain the populace of these regions. In India, this is generally grown under rainfed conditions where this crop uses the residual moisture efficiently. Despite the fact that barley is endowed with resilience to harsh climates, several abiotic stress factors inhibit the performance of the crop to its fullest genetic potential. Some of these stresses are drought, salinity and alkalinity, water logging, lodging, etc. Morphological and physiological traits linked to drought resistance in barley are early growth vigour, root development, tillering, grain weight, stay green habit, leaf water potential, stomata size, membrane stability, leaf rolling, waxiness, leaf temperature, carbon isotope discrimination and the accumulation of metabolites such as proline and betaine. Breeders have resorted to the development of semidwarf barley varieties through incorporation of dwarfing genes and to enhance stem strength to minimize the risk of lodging. Field screening for tolerance to salinity or alkalinity has not been very reliable; therefore, field screening supplemented with laboratory screening has been advocated in barley to breed varieties tolerant to salinity or alkalinity.