Evolutionary Trends in Leaf Photosynthesis and Related Leaf Characters Among Cultivated Wheat Species and Its Wild Relatives

Wild species of Triticum and Aegilops exhibited a markedly higher photosynthetic rate per leaf area (PA) as compared to cultivated wheat species. With a lower nitrogen content per leaf area. PA of cultivated wheats was lower than that of wild relatives, however, this low nitrogen content per leaf area was associated with the enlargement of leaf area which may bring about an increased utilization of solar radiation under a properly balanced water supply. The photosynthetic rate per unit leaf nitrogen (PN) was rather high in the leaves with a lower nitrogen content per leaf area.