Characterization of upland rice genotypes for drought tolerance and dormancy

Fifteen rice cultivars were grown in rainfed upland and exposed to severe water stress (soil moisture 5.5 –9.0%) for ten days to evaluate them for drought tolerance. The study revealed that the cultivars IET 18645 and IET 18460 could maintain their assimilatory surface area 130.2 and 135.1 cm2 plant-1, respectively even though their assimilatory units rolled to a maximum degree (leaf rolling score were 9 in both the cases) indicating their ability to escape drought through this mechanism. They were also able to maintain water potential in the leaf tissues to a desired extent. The cv. IET 18460 produced satisfactory grain yield of 2.18 t ha-1. However, cvs. IET 18645 and IET 18460 were at par with Bandana and all the three cvs. significantly registered higher grain yield compared to the check cv. Govind (1.13t ha-1). IET 18645, IET17509 and IET18781 exhibited strong dormancy behavior. IET 18645 showed longest grain dormancy of 28 days. Hence, IET 18645 can be identified as a potential donor for both drought tolerant upland rice cultivar and also longest grain dormancy.