Abstract:
Salt stress is a major constraint which limits rice production. In the present
study, 20 traditional rice cultivars were studied for salinity tolerance at the
seedling stage in a hydroponic system. The experiment was carried out
according to the completely randomized block design with four replicates
and 10 plants were included in each replicate. Dormancy broken, surface
sterilized rice seeds were germinated in distilled water for three days. After
three days germinated seeds were transferred to saline solution with
electrical conductivity 6 dS/m which was prepared by adding NaCl to
Yoshida solution. After three days, EC level was increased up to 12 dS/m in
the Yoshida solution. Nutrient solution was renewed in two day interval.
Seedlings were kept in the same conditions for 21 days. Green plant height,
root length and survival percentage of seedlings were evaluated on the 21st
day. Root dry weight and shoot dry weight were evaluated at the end of the
experiment after keeping materials at 70 oC for 7 days. Data analysis was
done using ANOVA with Statistical Analysis System and Duncan multiple
range test. Moddaikaruppan, Galpa wee, Heenati-309, Handiran,
Heendikwee and Dena wee scored more than 20% survival rate and the
highest survival rate was recorded by Moddaikaruppan (45.56%).
Muthumanikkam, and Dikwee totally died during the stress period.
Significantly highest green plant height (9.81cm) and root length (2.38cm) at
salinity stress were recorded by Moddaikaruppan (α=5%). There were
correlations in between survival percentage and plant height (r =0.927,
α=5%) as well as survival percentage and root length (r= 0.928, α= 5%).
There were no correlations in between survival percentage, root dry weight
and shoot dry weight. Among all the tested rice cultivars Moddaikaruppan
was the best salinity tolerant rice cultivar at the seedling stage.
