Deeper and profuse rooting is a harness able drought avoidance mechanism to develop aerobic rice lines. Traditional rice lines from Kerala were used for validating the relation between profuse rooting trait and drought tolerance traits. Twenty three rice lines with significant diversity was employed, along with Sahbhagi Dhan as check. The plants were raised in two distinct environments –hydroponics and root structure. In hydroponics, 10% PEG 6000 was used, that imposes a mild stress that can induce root growth in most cases. The root structure consists of a brick walled rectangular structure where soil was filled at 1.5 m height. The depth of rooting and total root length was distinctively recorded that identified genotypes namely Aathira, Mullan Channa, Shakti, Shreyas and Thekkan Chitteni as superior genotypes. These genotypes also maintained a relatively better root volume. In contrast, genotypes such as Karutha Njavara, Jeerakashala and Gandhakashala that failed to proliferate roots, developed relatively thicker roots. The genotypes with better RSA under all stresses maintained a relatively cooler canopy that helped to avoid water deficit stress. Our study signifies the relation between profuse root growth habit and canopy health which are key leads to develop drought tolerant rice.

Canopy temperature depression, Depth of rooting, Root diameter, Root system architecture, Total root length, Traditional rice

The study revealed significant variability among genotypes for various root architecture traits. This lays the foundation for identifying elite donor genotypes for various crop improvement initiatives. Trait specific and ideotype-based improvement can help to develop climate ready rice.

S. Krishna Adithya, M.S. Parvathi, R. Ramesh, P. Prameela, P.S. Abida and G.K. Krishna (2025). Deeper and Profuse Root System is a Major Determinant of Water Deficit Stress Tolerance in Rice. Biological Forum – An International Journal, 17(1): 36-41.