Plumule and radicle length
Plumule length of all the rice varieties decreased with an increase in salinity (Figure 1).
The plumule length was maximum in ADT43 and minimum in varieties ADT47 and Jeeraga samba at salinity levels of 4 and 8 dS m-1. At salinity level of 12 dS m-1, the maximum plumule length was recorded in ADT43 (Control variety) and the minimum in varieties, ADT47 and IR50.
When the salinity was reached to 16 dS m-1, plumule length was completely inhibited in three varieties (IR50, Jeeraga samba and TKM11). At 20 dS m-1, plumule length was observed in two varieties MDU5 and ADT43.
Reduction of seedling height is a common phenomenon of many crop plants grown under saline conditions [15].
Similarly, radicle length was also decreased with increased salinity (Figure 2).
Radicle length was more suppressed than plumule by salinity at all salt concentration levels.
The gradual decrease in root length with increase in salinity might be due to more inhibitory effect of NaCl salt to root growth compared with shoot growth.