Poly covering improves the morpho-biochemical and stress tolerance of rice under low-temperature conditions

Low-temperature (LT) stress adversely affects the morpho-physiological and biochemical attributes of rice seedlings which leads to increased hill mortality and reduced grain yield in the field. The study assesses the efficacy of poly covering (PC) in protecting rice seedlings from LT stress. Seedlings of two popular rice varieties (BRRI dhan28 and BRRI dhan29) were raised during LT in Gazipur and Rangpur districts of Bangladesh under open air (OA, without PC) and PC conditions. Findings revealed that the seedlings' dry matter, shoot length and root length in OA environment were reduced almost 50% compared to PC conditions. Leaf number and photosynthetic pigment content in OA-grown rice seedlings were about one-third of those observed under PC conditions. In contrast, OA-grown seedlings produced 2-3 times higher proline and malondialdehyde because of increased stress and oxidative damage. OA-grown seedlings of BRRI dhan29 were more infected to bakanae and BRRI dhan28 to blast disease particularly at Rangpur site. Irrespective of locations, both the rice varieties produced increased panicles number, and grains panicle −1 , which ultimately led to increased grain yield than those raised in OA environment. The PC appeared effective in mitigating LT stress of rice seedlings and subsequently contributing towards higher rice yield.