Photosynthesis of Lamina and Sheath of Barley Leaves

Publisher Website
Google Scholar
Abstract
Apparent photosynthesis, in mg. CO2 absorbed per dm.2 per hour, of the sheath and enclosed stem of a barley leaf was about 50 per cent. of that of the lamina of the same leaf, when the photosynthesizing area was measured as one side of the lamina and the outer exposed surface of the sheath. Apparent photosynthesis of a particular lamina or sheath was about 70 per cent. of that of the one above on the same stem. Respiration per dm.2, though not per g. dry weight, of sheath with enclosed stem was greater than of lamina in one experiment done with low-intensity illumination so that true rates of photosynthesis of lamina and sheath were similar. Differences in respiration rates per unit area of laminae and sheaths probably accounted for most of the greater apparent photosynthesis of the former in other experiments done with higher intensity illumination. It is suggested that for growth-analysis studies the size of the photosynthetic system of cereals should be measured as that of one side of the leaf laminae plus the outer surface of the combined leaf sheaths. In the later stages of growth the surface area of exposed stem and peduncle should also be included.

This publication has 0 references indexed in Scilit: