Abstract
Associations of stomatal frequency with heading date and leaf characters were studied. Nine six-rowed barley cultivars differing in stomatal f.requency were planted in the field in the fall of 1975. Stomatal frequency, dry weight, total nitrogen content, Ieaf vein frequency and leaf area of flag leaf were determined. Leaves were taken from the primary culm of each plant. The values of stomatal frequency, heading date, specific leaf weight(SLW), total nitrogen content per unit leaf area (N/LA), Ieaf vein frequency (LVF), ratio of SLW (1eaf thickness) to the distance between veins(SLW><LVF) (following KHAN and TSUNODA 1971), and leaf area (LA) of the nine cultivars are shown in Table 1. Correlation coeflicients were computed between stomatal Lrequency and other characters, and are presented in Table 2. SLW and N/LA, which are known to correlate with photosynthesis, had no positive correlations with stomatal frequency (Fig.1 and Table 2) . Correlation coefficients between stomatal frequency and LVF and also SLWXLVF were 0.24 and -0.05 respectively. So, LVF or SLWLVF, as the component of the efflciency 0L transport system for the products of photosynthesis, had no strong relationship with stomatal frequency. In conclusion, it appears that the correlation existing between stomatal frequency and photosynthesis is not because of the thick, nitrogen rich and well developed transport system in high stomatal frequency leaf but because of the effect of stolnatal frequency itself on photosynthesis.
