1. Pistil Length as Indicator of Ovule Stages and Use of Length and Width Means of Ovule Stages to Determine if Fibonacci Sequence is obtained in RC Brassica rapa L. Samad Syed*, and Bruce Smith Department of Biological Sciences, York College of Pennsylvania Introduction  Brassica rapa is a member of the mustard family and is closely related to many early spring, late fall vegetable crops e.g., cabbage, brussel sprouts, and broccoli. For decades it has been a favorite choice for studies in genetics, morphology, and molecular biology (Smith, 1991).  Quantitative studies have provided evidence for phylogenetic interpretations including early ovule comparisons within the haploid phase of dicot life histories (Smith, 1973). Purpose  The purposes are: to compare ovule development in B. rapa by measuring the lengths and widths of stages and then compare these stages to easily obtained pistil lengths (Smith, 1971, 1973). Finally, to compute Fibonacci sequence which can be obtained after two starting values, each being the sum of the two preceding numbers e.g., Fn = Fn−1 + Fn−2 with F1=1 and F2=2 (1,1,2,3,5,8,13,21,…) (Boeyen, 2003).  Once measured, the means of each developmental stage will be used to determine if the Fibonacci golden ratio can be obtained. Methods and Materials  RC Brassica rapa seeds and the necessary equipment needed to grow them under constant light in YCP greenhouse  Custom dissecting equipment for dissecting ovules  Fixative, Alcohol series, Herr Fluid Clearing Technique:  Fix the flowers using FPA50 (formulin, propionic acid) (min. of 24hrs)  Decant FPA50 to replace it with 70% Ethyl Alcohol (ETOH70) Dehydration Series:  70 → 80 → 90 → 95 → 100% ETOH → HERR Fluid ResultsConclusion  Megasporo-gametogenesis stages were successfully measured and compared to pistil length from which they were taken (see Table 2).  The Fibonacci sequence and the golden spiral was obtained from each of the developmental stages (Table 3). Work Cited Boeyen, J. C. 2003. Number patterns in Nature. Crystal Engineering 6(4):167-185. Smith, B.B. 1991. Comparisons of Early Ovule Development through Megagametogenesis in Rapid-Cycling Brassica rapa L. And B.campestris L. using the Herr Clearing Techniques. Springer-Verlag, New York, Berlin Smith, B.B. and J.M. Herr, Jr. 1971. Ovule Development, Megagametogenesis, and Early Embryogeny in Ammania coccinea Rothb. The Journal of Elisha Mitchell Scientific Society. Vol. 87:No. 4. Smith, B.B. 1973. The Use of a new Clearing Technique for the Study of Early Ovule Development, Megasporogenesis, and Megagametogenesis in Five Species of Cornus L. American Journal of Botany. 60(4): 322-338. Acknowledgements I would like to thank Dr. Bruce Smith, Dr. Bradley Rehnberg & Dr. Karl Kleiner for their support and guidance with this project. Ovule Stages  Meiotic Divisions (Megasporogenesis) A. MMC (Megasporo Mothercell)(2n) B. Dyad C. Tetrad (n)  Mitotic Divisions (Megagametogenesis)(n) D. FM (Functional Megaspore) E. 2-Nucleate F. 4-Nucleate G. 8-Nucleate BA FE DC G OvulePistil length