ABSTRACT
An experiment was
carried out at Sher-e-Bangla Agricultural University, Dhaka, Bangladesh
during the period from March to July 2014. Plants were grown in the rain-protected
polyethylene shelter or shed to avoid rain under natural conditions. The
experiment was conducted on biochemical characters of aus rice varieties in
various soil moisture levels in three rice genotypes as BRRI dhan55 (V1),
BR6976-2B-15 (V2), and
tolerant check Hashikalmi (V3), and
seven water stress were imposed as treatments. Treatments were 0 days of water stress (control) irrigated continuously throughout the experimental
period (T0). From twenty days onwards water stress was imposed for
seven days when the age of the seedling was 20 days (T1), 35 days (T2),
55 days (T3), 75 days (T4), 95 days (T5), and 115
days (T6). Our findings suggest that the proline, starch, and
sugar content were also found comparatively higher in BRRI dhan55 and Hashikalmi among the
genotypes under water stress conditions. Under
water stress conditions, proline was accumulated, sugar, and starch were decreased. The soluble sugar content was much lower under water
stress conditions due to lower RWC, chlorophyll content, stomatal conductance, and
higher leaf rolling. Leaf accumulates anthocyanins under drought conditions and
the red color increased as the intensity of water stress increased.