Distribution of acid, saline, alkaline and flooded soils globally; plant growth and yield under adverse soil conditions; plant responses and genotypic variation in acid soils, aluminium toxicity and aluminium tolerance; alkaline soils, physiological and morphological adaptation mechanisms of plants to mineral nutrient deficiencies (i.e.,phosphorous, iron and zinc); adverse effects of salinity on plant growth, genotypic variation in adaptation to saline soils; heavy metal contamination; genotypic differences in uptake and transport of heavy metals, phytoremediation and metal-hyperaccumulators.