Effects of Ozone and Soil Salinity, Singly and in Combination, on Growth, Yield and Leaf Gas Exchange Rates of Two Bangladeshi Wheat Cultivars

Abstract

In Bangladesh, increases in the tropospheric ozone (<TEX>$O_3$</TEX>) concentration and in soil salinization may lead to crop damage. To clarify the effects of <TEX>$O_3$</TEX> and/or soil salinity on Bangladeshi wheat cultivars, BAW1059 (salt-tolerant) and Shatabdi (salt-sensitive) were exposed to 70-day treatments with <TEX>$O_3$</TEX> (charcoal-filtered air (CF), <TEX>$1.0{\times}O_3$</TEX>, and <TEX>$1.5{\times}O_3$</TEX>) and different levels of soil salinity (0, 4, and <TEX>$8dS\;m^{-1}$</TEX>). In both cultivars, the whole-plant dry mass and grain yield were significantly reduced by exposure to <TEX>$O_3$</TEX>. Increased soil salinity caused significant reductions in whole-plant growth and yield in Shatabdi, but the reductions were negligible in BAW1059. No significant interactions between <TEX>$O_3$</TEX> and salinity were detected for growth, yield, and leaf gas exchange parameters in both cultivars. We concluded that the effects of <TEX>$O_3$</TEX> are not ameliorated by soil salinity in two Bangladeshi wheat cultivars, regardless of their salinity tolerance.