Monday, November 13, 2006

Leaf Cuticle Characteristics of a Cool-Season and Warm-Season Putting Green Turfgrass Species.

J. C. Stiegler, M.D. Richardson, D.E. Karcher, D.M. Oosterhuis, J.B. Murphy, S.C. Goeke, and E.M. Martin. University of Arkansas, 316 Plant Sciences Bldg., Department of Horticulture, Fayetteville, AR 72701

The leaf cuticle is a thin (~30µm), waxy protective layer that envelops the outermost portion of a leaf, enabling plants to avoid uncontrolled evaporative water loss and leaching of nutrients during irrigation or rainfall.  It also serves to shield plant leaves from insect, fungal, and foreign chemical penetration.  From a crop management perspective, the cuticle is also the initial point of contact for foliar-applied chemicals and fertilizers and it has a significant effect on the absorption of sprayed solutions.  Previous research has shown that the plant cuticle is dynamic and responds to leaf age, environmental changes, and varies among plant species.  However, little is known about the nature of the leaf cuticle layer in turfgrasses or the factors that may affect it.  A study was conducted to comprehensively analyze the turfgrass leaf cuticle of a cool-season (Agrostis stolonifera var. palustris L. Huds. cv. ‘A1’) and warm-season (Cynodon dactylon x transvalensis cv. ‘Tifeagle’) turfgrass species.  Leaf tissue samples were examined for the following parameters: thickness of the cuticle, leaf cuticle surface morphology, total wax content of leaf surfaces, and cuticular wax composition.  Data were obtained using transmission and scanning electron microscopy, chloroform wax extraction, and gas chromatography of cuticle components.  Results indicate that the cuticle of turfgrass species is affected by grass species and is likely affected by environmental changes. The information obtained from these studies will be useful in the development and efficacy of foliar-applied chemicals and fertilizers in high-maintenance turfgrass areas.