Abstract
This chapter reviews genetic diversity in barley and its role in improving varieties, including adaptation to abiotic stresses. Sulphur is an essential macronutrient required in plants for normal growth and development. Its deficiency in agricultural soils reduces grain yield and grain quality traits. Studies conducted with barley and wheat varieties demonstrate substantial variations among crops and varieties in their response to application of different levels of sulphur. The chapter looks at factors affecting sulphur nutrition in barley and the potential role of genetic differences in breeding more resilient varieties.