Abstract
Photosynthetic rate per leaf area (PA) was positively correlated with transpiration rate, dark resipration rate, nitrogen content per leaf area and specific leaf weight. Optimum air flow rate for PA differed according to leaf size. Diploid species with smaller leaves showed the highest PA at lower air flow rate. In warmer season PA was higher in spring types while in cold season it was in winter types. Wild types generally showed high nitrogen content per leaf area and high PA as compared with cultivated types. Light saturation was not observed up to 80 klx for any of 20 strains investigated.