Temperature induced changes in wheat (Triticum aestivum) growth and yield under salt affected environment of Indo-gangetic plains

Abstract

An attempt has been made in the field conditions to evaluate the effect of atmospheric temperature rise on yield, ionic ratio (Na:K), and accumulation of antioxidative pigments in wheat in different growth stages under different soils. Five planting windows (PW) were classified, based on date of wheat sowing where the average temperature difference between a particular PW and PW-I varied from 1.33–4.24°C. Plant leaf area and root length density showed decreasing trend with increasing temperature. A low flag leaf water potential (−1.14 MPa) in sodic soil and high solute potential (−1.34 MPa) in saline-sodic soil was observed under PW-V, where high temperature difference (4.24°C) was recorded. The Na:K ratio was found to be highest in both straw and grain which were 1.802 and 1.126%, respectively, under saline-sodic conditions in PW-V. Proline and malondialdehyde concentration was highest under sodic conditions which varied between 2.82–2.95 mg g−1 fresh weight (FW) and 18.38–30.18 nmol g−1 FW, respectively, under maximum temperature difference. An increase in temperature (>1°C) significantly reduced grain yield (>10%) that was negatively correlated with Na+ (r = −0.78) but positively with K+ (r = +0.62) concentrations under saline-sodic conditions, however under sodic conditions, it was positively correlated with K+ (r = +0.63) concentration. Therefore, looking in to the climate change scenario, shifting planting window of wheat sowing may be helpful in mitigating the negative effects of heat and salt stress on wheat crop.

KEYWORDS: Malondialdehyde, proline, salinity, sodicity, yield