|Pienaar, J - RSA, ARC|
Submitted to: Grassland International Congress Proceedings
Publication Type: Proceedings
Publication Acceptance Date: June 8, 1997
Publication Date: N/A
Interpretive Summary: The productivity and feed value of warm-season grasses for cattle and other ruminant animals has been related to the internal structure of the grass leaf. We used a collection of switchgrass plants that varied in productivity and feed value to test these relationships. We sampled leaves of switchgrass and processed them so that we could examine them under a microscope. We tested cross sections for internal and external leaf dimensions within this collection. Differences were found and we developed a graphical way of representing the differences we measured. Measurements of the vessels within the grass leaves varied as well as the overall thickness of the leaves. Work is continuing to relate these internal and external leaf dimensions to grass productivity and feed value.
Technical Abstract: Both the yield and digestibility of C4 grasses have been related to anatomical characteristics. The objectives of the current work were to test switchgrass with varied yield and digestibility for variation in anatomical measurements and to develop a method of graphically representing the anatomy. Six accessions were established in replicated field plots and the lamina were sampled, dehydrated and embedded for anatomical study. Midrib dimensions were excluded from study but perimeters of primary and secondary vascular bundles in the lamina were measured. Lamina thickness was determined at the primary bundle, secondary bundle and at the minimum between the bundles. The distance between the primary and secondary bundles was also measured. The accessions differed in perimeter of primary vascular bundles, lamina thickness at the primary bundle and the distance from primary to secondary vascular bundle (P<0.05). Variation in lamina thickness at the secondary vascular bundles approached significance (P<0.10).