Effect of water stress on photosynthesis and growth in two teak phenotypes

Two teak (Tectona grandis L.f.) phenotypes differing in their leaf length/b readth ratios were subjected to water stress by withholding water supply fo r three weeks. Growth rates of whole plants, developing leaves (1(st) and 2 (nd) from shoot apices), and 2(nd) and 3(rd) internodes were higher in broa d leaved (BL) phenotype than in narrow leaved (NL) phenotype before and aft er imposing water stress treatment. However, the effect of water stress on these parameters was higher in the BL phenotype than in the NL one, Diurnal course of net photosynthetic rate (P-N) of 3(rd) of 4(th) leaves from shoo t spices measured under well-watered conditions was higher for the NL than BL phenotype, P-N, stomatal conductance (g(s)), and transpiration rate (E) in both phenotypes were negatively affected by water stress and their decli ne under water stress was significantly higher in the BL than NL plants.