Histology of several cool-season forage grasses digested by cellulase

摘要

Leaf blade sections (3 cm long) from the last fully collared leaf of plants from genotypes of perennial ryegrass (Lolium(multiflorumLam. #xD7;perenneL.) #xD7;perenneL.), tall fescue (Festuca arundinaceaSchreb.), timothy (Phleum pratenseL.), and brown top (Agrostis tenuisSibth.) were digested by a fungal cellulase solution. Light microscope observations showed there was a similar pattern of digestion by cellulase in all the species studied. Digestion occurred first in the mesophyll, followed by disappearance of the epidermis and phloem. Cellulase did not digest the cuticle, sclerenchyma, or xylem. The observed pattern of digestion of fresh leaf blades by cellulase was similar to that reported previously for rumen liquor, except that digestion by cellulase was faster. Differences in rate of degradation by cellulase were demonstrated among species and between genotypes of the same species. Digestion of fresh grass leaves by cellulase is a potentially useful screening technique for breeding forage grasses that differ in their rates of digestion by ruminants.