Comprehensive screening of some west and central african sesame genotypes for drought resistance probing by agromorphological, physiological, biochemical and seed quality traits

Abstract

Sesame is an important crop in West and Central Africa playing a role of an alternative cash crop for smallholders. However, sesame productivity is highly impaired by drought. This study aimed at identifying some drought-resistant genotypes and efficient screening traits in large sesame germplasm. Ten genotypes were examined based on 21 biochemical, physiological, agromorphological and seed quality traits under three weeks of water stress. A high variability for drought resistance was observed among the genotypes. The genotypes WC17, WC18 and WC14 were drought resistant, WC12, WC13, WC06 and WC03 were moderately drought resistant while, WC02, WC10 and WC08 were drought sensitive, based on principal component analysis. The resistant genotypes exhibited both avoidance and tolerance features including increase of the root system, reduced water loss, highest activity of antioxidative enzymes and accumulation of proline. They produced higher biomass and had higher ability to maintain seed quality under drought stress compared with the sensitive genotypes. Strong accumulation (~200% ratio stress/control) of biochemical markers including superoxide dismutase, ascorbate peroxidase, catalase and proline could be regarded as an important indicator for selecting drought resistant genotypes. This study represents a reference for future research towards developing new varieties with improved drought resistance in West and Central Africa.