The α‐Tocopherol content of leaves as affected by growth rate

Abstract α‐Tocopherol was quickly extracted from small samples of leaf with acetone, transferred to petrol, purified by two‐dimensional paper chromatography, and determined by the Emmerie–Engel test. Fast‐growing leaves of Lepidium sativum (cress), Lactuca sativa (lettuce) and other plants had tocopherol contents of about 70 p.p.m. based on dry matter (7 p.p.m. fresh weight); while evergreen and other slow‐growing leaves had up to 1400 p.p.m. (450 p.p.m. fresh). In long leaves of grass, iris, narcissus and other plants the α‐tocopherol content was low near the base where growth is fast and maximal near the apex where growth is slow. In young short leaves of narcissus the gradient was only slight. Tocopherol contents of leaves increased during summer and reached maxima in autumn or winter. In leaves of two conifers the maximum concentration was reached in the third winter. In evergreen leaves the values fell in spring. Dying and fallen leaves had higher contents than green leaves. In blooms of narcissus the α‐tocopherol contents diminished considerably during development. It is concluded that α‐tocopherol content of leaves is inversely related to growth rate.