Identification of drought-tolerant traditional cultivars of rice (Oryza sativa L.) under different terminal water stress environments

Abstract:

Drought is one of the most important abiotic stresses causing considerable yield loss in local rice cultivars. Water stress at the reproductive phase is a common phenomenon in many long-duration rice-growing areas. Traditional rice cultivars pass through the terminal drought. In this endeavor, 59 local cultivars of rice were screened under terminal drought created by spraying potassium iodide, normal terminal drought, and a control block (irrigated condition) based on some of the drought tolerance indices. The study exhibited a reduction in mean grain yield in both drought conditions by 21.42% and 6.81%, respectively. The best ten performing cultivars under non-stress conditions were Jhagrikartik, Ghee Bora, Hatidat Komal, Panikuthi Shyamlal, Sial Bhomra, Garu Chakua, Silathia Bora, Tulsimukul, Tarapakri, Dudhekalam. Of those, Jhagrikartik, Ghee Bora, Panikuthi Shyamlal, and Tulsimukul also performed well under stress conditions created by spraying potassium iodide, however, the cultivars Hatidat Komal, Garu Chakua, and Silathia Bora also performed well under normal terminal drought environment. Nine drought-tolerant indices were used to find out the better-performing rice cultivars. Based on combination of different drought tolerant indices under different drought conditions Panikuthi shyamlal, Ghee Boraand Jhagrikartik were found to be promising under drought stress environments. Ladu and Kaltury were also found to be better under drought conditions. The novelty of this endeavour includes the use of potassium iodide to create a drought situation for screening tolerant genotypes in addition to the normal drought environment.