Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: October 12, 2010
Publication Date: N/A
Technical Abstract: Plant root models are designed for understanding structural or functional aspects of root systems. When a process is not thoroughly understood, a black box object is used. However, when a process exists but empirical data do not indicate its existence, you have a black hole. The object of this research was to develop a data set, from which to model perennial ryegrass (Lolium perenne L. - PR) root growth and development, however, 4 black holes were discovered. These previous black holes are: (1) PR lateral roots may be determinate or indeterminate in growth depending on the clone; (2) a dominant type of lateral root, was discovered, which initiates, seemingly randomly, grows out fast, and is larger than typical lateral roots, and may be the primary adaptive basis for PR root system response to the environment; (3) surface seeded or shallow seeded seedling root systems are composed of four distinct classes of root rather than two; (4) coleoptile node roots, which are not classified as a separate class in the accepted nomenclature, are an integral part of the PR root system. Because different root classes are functionally and developmentally distinct, it is necessary to model and/or study them separately. Therefore, a modified nomenclature is proposed, to support this type of discrimination. A preliminary model data base is developed but needs significant improvements to adequately account for these four new processes.