Abstract:
The root morphological traits in plants can be used as a proxy to determine the
varietal performance under varying environmental conditions. Our study
aimed to identify root morphological traits that can impact the salinity
susceptibility of rice varieties at the seedling stage. The study compares the
root morphologies of salinity-tolerant (Bg 369, At 354) and salinitysusceptible
(Bg 360, Bg 352) rice varieties under two conditions (saline
stress:12 dS/m, without saline stress). The rice varieties were grown in a
hydroponic (Yoshida) medium under non-stress and saline stress. The
standard evaluation score for visual salt injury was taken using visual
observation 5, 10, and 15 days of salinity induction. After 16 days, the treated
roots were extracted and scanned using WinRHIZO root scanner (2015) to
obtain root morphological parameters including root average diameter (AD),
root surface area (SA), root volume (V), and total root length (TL). Analysis
of variance was conducted using STAR 2.0.1 (IRRI, Philippines) using a 5%
significance level followed by turkey pairwise comparisons. The percentage
reduction for each trait was calculated. The reduction percentages of the root
traits due to the salinity treatment are significantly lower in salinity-tolerant
varieties compared to the salinity-susceptible varieties with regard to V, SA,
and TL. Under non-stress conditions, the AD of the salinity-susceptible
varieties was significantly different from the AD of the salinity-tolerant
varieties. Our findings indicate that the root morphological traits investigated
can be used to distinguish between the selected salinity-tolerant and
susceptible rice varieties under saline-stress and non-stress conditions.
