Lulli Filippo, Guglielminetti Lorenzo, Grossi Nicola, Armeni Roberto, Stefanini Sara, Volterrani Marco
Department of Agronomy and Management of the Agroecosystem, University of Pisa, Via San Michele degli Scalzi 2, 56124, Pisa, Italy.
Department of Plant Crop Biology, University of Pisa, Viale delle Piagge 23, 56124, Pisa, Italy.
Funct Plant Biol. 2011 Nov;38(11):919-926. doi: 10.1071/FP11070.
The intrinsic resistance of plant tissue to several biomechanical stresses, including tensile stress, is a decisive factor in determining the wear resistance of a turfgrass species. Lignin, dry matter, starch, sugars and silica are some of the tissue constituents that have been associated with leaf and stem mechanical resistance, whereas little information is available concerning stolons and rhizomes. These organs not only enable C4 turfgrass species lateral growth, soil colonisation and injury recovery, but are also key constituents of mature swards. This study consisted in an extensive investigation on the effective leaf, stolon and rhizome tensile strength of Cynodon dactylon (L.) Pers. var. dactylon×C. transvaalensis Burt-Davy cv. Tifway 419, Zoysia matrella (L.) Merr. cv. Zeon and Paspalum vaginatum Swartz. cv. Salam, as measured with a Fédération Internationale de Football Association (FIFA)-approved dynamometer and correlating the results with laboratory investigations on key tissue constituents. Tensile strength per unit area was influenced by both tissue constituents and tissue dimension. In rhizomes and stolons, tissue breakage usually occurred in the area at the intercalary meristem at the apical zone in the immediate proximity of a node. Older tissues had higher tensile strength owing to their higher levels of lignification. Lignin was the principal constituent determining tissue tensile strength and as such it could be used as a turfgrass wear resistance predictor in the cultivar breeding stages. Stolon total soluble sugars were generally inversely proportional to lignin content and, therefore, can also be considered clear markers of tissue mechanical strength. Silica was found to have no influence on the mechanical properties tissues.
植物组织对包括拉伸应力在内的多种生物力学应力的内在抗性，是决定草坪草物种耐磨性的一个决定性因素。木质素、干物质、淀粉、糖类和二氧化硅是一些与叶片和茎杆机械抗性相关的组织成分，而关于匍匐茎和根状茎的信息则很少。这些器官不仅使C4草坪草物种能够横向生长、在土壤中定殖并从损伤中恢复，而且也是成熟草皮的关键组成部分。本研究对狗牙根（Cynodon dactylon (L.) Pers. var. dactylon×C. transvaalensis Burt-Davy cv. Tifway 419）、沟叶结缕草（Zoysia matrella (L.) Merr. cv. Zeon）和海滨雀稗（Paspalum vaginatum Swartz. cv. Salam）的有效叶片、匍匐茎和根状茎的拉伸强度进行了广泛研究，使用国际足球联合会（FIFA）批准的测力计进行测量，并将结果与对关键组织成分的实验室研究相关联。单位面积的拉伸强度受组织成分和组织尺寸的影响。在根状茎和匍匐茎中，组织断裂通常发生在靠近节点的顶端区域的居间分生组织处。较老的组织由于其较高的木质化水平而具有更高的拉伸强度。木质素是决定组织拉伸强度的主要成分，因此它可在品种选育阶段用作草坪草耐磨性的预测指标。匍匐茎总可溶性糖通常与木质素含量成反比，因此也可被视为组织机械强度的明确标志物。发现二氧化硅对组织的机械性能没有影响。
