Received: June 2nd, 2022 ; Accepted: August 4th, 2022 ; Published: August 18th, 2022 ; Correspondence: [email protected] low temperature (LT) is detrimental to growth of rice seedling during boro season
in Bangladesh. An experiment was conducted in growth chamber during June to October, 2021
using BRRI dhan29 as planting material. The aim of this experiment was to determine the effect
of variable duration of LT on growth, physiological and biochemical traits of rice seedling and to
determine the age of seedling that can tolerate cold effect. In this experiment 5, 10, 15 and 20
days old seedling (DOS) were exposed to 6 °C for 1, 2, 3 and 4 days. Seedlings were also grown
under room temperature (25 °C, RT) which consider as control treatment. Seedlings were grown
in plastic trays filled with mixture of soil and cowdung. The experiment was conducted following
completely randomized design with 3 replications. Data on shoot length and weight, root length
and weight, chlorophyll (Chl), carotenoids, malondialdehyde (MDA) and proline contain were
determined after 5 days of temperature sock. The results revealed that the LT was injurious to
younger rice seedling when they were exposed to LT for 1 to 2 days. The shoot and root length
as well as their dry weight were reduced under low temperature. Further, the Chl and carotenoid
content of younger rice seedlings degraded within 2 days of LT exposure. On the contrary, the
proline and MDA content of rice seedlings increased to reduce the harmful effect of under LT. It
could be concluded that the rice seedlings could tolerate the detrimental effect of LT when they
attain at least 15 days
