Poster: Vegetative Development

Abs # 454: Leaf growth analysis: a simple leaf analysis model describes the cell growth patterns of dicotyledonous leaves

Presenter:	Chen, Yung-reui , yrc@ms.cc.ntu.edu.tw
Authors	Chen, Yung-reui  (A)   Chyi-Chuann,  Chen  (A)
Affiliations:	(A): National Taiwan University

In the article we characterized the fundamental features of leaf growth curve, fitting and differentiatating the leaf growth curve was first performed with Ficus formosana Maxim.plants. Leaf length was measured for 5 to 15 successive leaves acropetically on the shoot of F. formosana Maxim. The leaf growth curve was obtained by fitting the growth data with the sigmoidal growth function. The second differentiation of sigmoidal equation by using the program of the Microsoft ORIGIN 4.0 shows two reflection points. Based on the model, the first reflection point was time for cell division first stopped on the leaf tip region. The second reflection point is the cell division stopped on the basal region of the leaf. Between the first and second reflection points, leaf development is in the process of cell division ceased and cell elongation increased exponentially, gradually and basipetally. The growth data could be divided into three groups by this two reflection points and they also be fitted with adequate functions for log, linear and stationary phases, respectively. Three mathematic functions, exponential function, linear polynomial function and cubic function were tested for synergying leaf growth curve. This model provide a good tool for studying the different environment factors affecting the cell division and/or cell elongation during the leaf development.