Insights into Sesame (Sesamum indicum L.) Root System Architecture for Enhanced Productivity: Results of a Root Structure Study

Sesame (Sesamum indicum L.) is considered to be one of the oldest domesticated oilseed plants in Asia for over 5000 years in wide range of soil moisture environments. The root system architecture of sesame was so resistant to water scarcity but not water logging. However the variation among the available Sesame land races, genotypes etc suited to varied agroecologies and the root traits’ contribution to crop productivity has not been explored precisely. To understand the root system architecture, the root traits viz., root depth, root volume, root length density and root mass at successive soil depths and their relationship with the seed yield vis-a-vis aerial biomass, experiments were conducted in root structure (1.2 x 2 x 30 m³) using high yielding selected germplasm accessions from Indian core collection- IC-204300, IC-205471, IC-43036, IC-132300, IC-132186, IC-205649, IC-204090, IC-204622, IC-132171 and selected varieties adapted to dry environment- RT-346, RT-135, Swetha til, JCS DT-26 along with national checks TKG-22, GT-10. The results indicated that while the root depth varied from 40 to 80 cm, the genotype IC-205649 registered the maximum with IC-132300, the minimum. The root volume and root length density also varied from 0.29 to 0.47 cm cm³ and the maximum root volume in terms of more lateral and profuse root system was found in JCS DT-26, IC-204090, IC-204 622 as compared to other genotypes and national checks. A positive relationship (R²: 0.34) between seed yield and root length density was observed along with shoot growth (R²: 0.42) indicating that the genotypes with profuse lateral root system can explore more water and nutrient from soil profile contributing to higher seed yield. The JCS DT-26, IC-204090, IC-204 622 genotype with potential root traits can be a target for location specific variety development in sesame breeding program.