Effect of various environments on the anatomy and growth of Perennial Ryegrass and Cocksfoot

Abstract

Plants of Lolium perenne and Dactylis glomerata were given in 100. 80, and 20% of full daylight, at mean day temperatures of 10.6, 15.2, and 20.5°c. Half the plants of each species were defoliated at transfer to the experimental conditions. Measurements were confined to the main tiller. Treatments induced differences in lamina length of 10- and 20-fold for ryegrass and cocksfoot respectively, and of 15- and 30-fold in area of leaf produced in 17 days. Defoliation and shading had their greatest effects on lamina length, while temperature had its greatest influence on rate of leaf appearance. Rate of leaf area formation of the tiller was greatly reduced by defoliation, substantially increased by a rise in temperature, and variably affected by shading. Though rates of leaf elongation were generally similar for the two species, ryegrass formed fewer but longer leaves. Abaxial epidermal cell length was reduced by defoliation, and substantially increased by heavy shading. Ryegrass cells reached their maximum length at a lower temperature than did those of cocksfoot. Epidermal cell width was less affected. The effect of treatment on number of cells along the lamina was greatest for cocksfoot, while a greater effect on cell length showed in ryegrass. Some treatments even had opposite effects on cell length and number. Cell width and number of epidermal cells across the lamina both varied with the environment, but lamina width was more closely correlated with cell number than with cell width.