An insight into the mechanisms of intermittent drought adaptation in sesame (Sesamum indicum L.): linking transpiration efficiency and root architecture to seed yield

• Published in: Acta physiologiae plantarum 2021-11, Vol.43 (11), Article 148
• Main Authors: Pasala, Ratnakumar, Pandey, Brij Bihari, Gandi, Sowjanya Lakshmi, Kulasekaran, Ramesh, Guhey, Arti, Vishnuvardhan Reddy, A.
• Format: Article
• Language: English
• Subjects: Agriculture; Biomedical and Life Sciences; Crop improvement; Crop yield; Depletion; Drought; Genotypes; Life Sciences; Organs; Original Article; Plant Anatomy/Development; Plant Biochemistry; Plant Genetics and Genomics; Plant growth; Plant Pathology; Plant Physiology; Plant roots; Planting density; Rooting; Sesamum indicum; Soil moisture; Transpiration; Water availability; Weight
• ISSN: 0137-5881; 1861-1664
• DOI: 10.1007/s11738-021-03324-z

Intermittent drought is a recurrent phenomenon in several parts of the world which limits the productivity of sesame ( Sesamum indicum L.) under rainfed conditions. As plant roots are the primary organs to sense soil moisture depletion, this study examined root morphological traits [(rooting depth (RL), root volume (RV), and root length density (RLD)] with plant functional traits [total transpiration (T) and transpiration efficiency (TE)]. Nineteen diverse genotypes were used under two water availability environments [intermittent drought (WS) and irrigated (WW) conditions]. The root traits and yield components were studied by growing them in a series of uniform polybag structures. Rooting depth and root length density varied significantly among the genotypes under WS conditions, but there was less variation in WW conditions. A weak relationship was established between root length density and T under both WW ( R 2 : 0.19) and WS ( R 2 : 0.10) conditions indicating that root length density could not be an adaptive trait under both conditions. However, TE with root length density ( R 2 : 0.32), harvest index (HI) with TE ( R 2 : 0.69), seed weight per plant with TE ( R 2 : 0.65), and seed weight with HI ( R 2 : 0.44) explained significant and positive relationship under WS conditions. Among sesame genotypes, IC-204622, IC-132186, IC-132207, IC-205471, and IC-73164 were performed better with high TE, HI, and seed yield under WS than other genotypes suggesting using these genotypes in a crop improvement program for the development of varieties adapted to drought.