Poster: Reproductive Development

Abs # 493: Mu-Tagged Empty Pericarp Mutants in the UniformMu Maize Population

Presenter:	Xue, Song , xue416@ufl.edu
Authors	Xue, Song  (A) (B)  Settles, Mark A (A) (B)  Huang, Li-Fen  (A) (B)  Avigne, Wayne T (A) (B)  Larkins, Brian A (C) (D)  Becraft, Philip W (E) (F)  Dukes, Will  (A) (B)  Baier, John W (A) (B)  Curt, Hannah L (A) (B)  McCarty, Donald R (A) (B)  Koch, Karen E (A) (B)
Affiliations:	(A): University of Florida (B): Plant Molecular and Cellular Biology Program (C): University of Arizona (D): Department of Plant Science (E): Iowa State University (F): Zoology and Genetics Department

A phenotypic analysis was undertaken to further define the extent of variation among the Mu-tagged empty pericarp (ep) mutants isolated from the UniformMu population. The ep mutants identified thus far (ca 25% of total Mu-tagged seed mutants) were initially classified on the basis of external visual analysis that indicated little or no internal seed structure was present. However, examination via longitudinal sections showed significant endosperm and/or embryo formation in many ˇ°epˇ± kernels. The range in degree of mutant severity revealed corresponding differences in timing of developmental termination for embryo and/or endosperm. The ep mutants of intermediate severity in this population often showed evidence of initial endosperm or nucellar development resulting in hollow, translucent, paper-like structures within kernels. For most ep mutants, abortion or retardation of embryo development appeared to have occurred at or before the transition stage between differentiation of the coleoptile and formation of the first leaf primordium. Extent of endosperm formation varied widely and was not necessarily related to degree of embryo development. Most endosperms were hollow or largely so. Further analysis will be directed toward identifying the sites and timing of developmental cessation in the different ep classes observed in the UniformMu population, and on molecular isolation of the relevant genes.