Evaluation of wheat genotypes for salt tolerance based on some physiological traits

Abstract

Identification of physiological markers related with salt tolerance during various vegetative and reproductive stages is crucial for evaluating wheat genotypes and improving their salt tolerance. Two salt-tolerant (Shatabdi and BAW 1135) and two salt-sensitive (BARI Gom 26 and BAW 1122) wheat genotypes of Bangladesh were grown in three salinity levels (control, 6 dS m-1, and 12 dS m-1) to observe the sensitivity of some physiological traits.. Salt-tolerant wheat genotypes maintained lower levels of leaf Na, higher levels of leaf K, and greater K/Na ratios in saline conditions than the sensitive one. Due to salt stress, flag leaf proline content was increased in salt-tolerant wheat genotypes whereas the proline level was decreased in the sensitive one compared to the control. Salt-sensitive genotypes showed a greater increment in SPAD (relative chlorophyll content) value at moderate salt stress but a greater reduction in SPAD values at high salt stress than tolerant ones. Salt-sensitive genotypes were affected more in their straw yield and finally grain yield plants-1 under saline conditions than salt-tolerant genotypes. There was a highly significant negative correlation between grain yield and Na content and also a highly significant negative correlation between grain yield and K: Na content of the wheat genotypes under saline environments. We also observed stress susceptibility index (SSI) based on grain yield plant-1 the order of tolerance was BAW 1135 > Shatabdi > BARI Gom 26 > BAW 1122 at moderate salinity level and BAW 1135 > Shatabdi > BAW 1122 > BARI Gom 26 at high salinity.