Abstract:
Many physiological functions and morphological properties determining yield of cotton plant may inhibited by different
water regimes. The aim of the present study was to investigate morpho-physiological adaptation of cotton plants to
different irrigation regimes. For this purpose, a pot experiment was conducted under fully controlled growth chamber.
Cotton plants (Gossypium hirsutum L.) were exposed three irrigation regimes. Plants were irrigated when water holding
capacity reach 20%, 40% and 60% to field capacity in I20, I40 and I60 treatments respectively. Physiological
parameters such as transpiration, canopy temperature depression (CTD) and SPAD values and morphological
parameters such as adaxial and abaxial stomatal density were determined. Lowest transpiration found in I20 treatments
than I40 and I60 treatments. SPAD value remained lower level in I20 treatment whereas higher in I60 treatments during
different irrigation regimes. Stomatal density was higher in adaxial surface than abaxial surface of leaves. On the other
hand, increasing stoma number per unit leaf area in adaxial surface with lower irrigation frequency was recorded. Our
results suggested that cotton plants adapt to different water regimes via regulating transpiring organs and their
functions.
