Department of Chemistry and Biochemistry, Haryana Agricultural University, Hissar-125004
Four wheat genotypes, namely, HD-2009 and WH-157, representing high yielding group, and C-306 and C-591, representing low yielding group, were analysed for flag leaf stomatal frequency, stomatal conductance, rate of photosynthesis and RuBP carboxylase activity at 7 days interval starting from anthesis to complete maturity. The four wheats differed signiicantly in respect of stomatal frequency both on adaxial and abaxial flag leaf surfaces. Similary, the differences were significant for stomatal conductance, RuBP carboxylase activity and rate of photosynthesis. Low yielding cultivars were having significantly higher stomatal frequency than high yielding cultivars, whereas reverse was the case for rate of photosynthesis and RuBP carboxylase activity, resulting in a negative association between stomatal frequency and rate of photosynthesis, RuBP carboxylase activity and yield. Stomatal conductance, on the other hand, had no relationship with yield.
