Investigation of Ovule Development in Relation to Coinciding Bud, Pistil, and Anther Locule Lengths in Arabidopsis thaliana (L.) Landsberg erecta Ecotype Ryan Catton

Introduction:•A.thaliana was the first plant to have its entire genotype mapped.

•Attention has been directed to the minute size of the megagametophyte in relation to the sporophytic generation and the taxonomic importance that could be given to these variations ( Herr, 1967; Smith, 1973).

•Previous studies of Arabidopsis ecotypes have attempted to relate bud length with coinciding pistil length as well as stages of early flower development (Dillaha 2006).

•A. thaliana has developed to into being one of the most popular plants for both genetic and organismal research.

Objectives:•This study aims to compare bud length, pistil length(done previous) as well as anther locule (new research) length with stages of embryo sac development of a different ecotype: A. thaliana.

•By comparing these structures to various ovule developmental stages it will allow for a speeder means of processing the stage of a particular ovule within the developing flower.

Methods:

Whole flowers removed at various stages of growth

and fixed in FPA 50.

Flowers dehydrated to 100 ethyl alcohol.

Flowers cleared using Herr fluid.

Bud length and coinciding pistil and anther locule

measurements were recorded using phase contrast microscope..

Ovules dissected from cleared ovaries and examined under microscope to determine

stage of embryo sac development.

Results:

Figure 1. Mean bud length with coinciding pistil and anther locule lengths categorized by stage of embryo sac development.

Figure 1.

Figure 2. Figure 3.

Figure 2. Correlation betweenBud length and coinciding pistil Length. Pearson correlation analysis was computed on means (r value of 0.9934).

Figure 3. Correlation between Bud length and coinciding anther locule Length. Pearson analysis was computed on means (r value of 0.9746).

Discussion. The use of Herrs’ clearing process aloud for measurement of bud length, pistil length, and anther locule length along with finding the coordinating stages of ovule development. The correlation between the physical floral measurements and stages of embryo sac development will allow for faster screening of buds in future studies .

Literature cited:•Dillaha, A 2006 Identification of Ovule and Embryo Sac Developmental Stages using Coinciding Bud Length in Arabidopsis thaliana (L.) Heynh Columbia Ecotype •Herr, J.M., Jr. 1971. A new clearing-squash technique for the study of ovule development in angiosperms. American Journal of Botany 58: 785-790•Smith, Bruce. 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. •"TAIR - About Arabidopsis." TAIR - Home Page. Web. 10 Dec. 2009. <http://www.arabidopsis.org/portals/education/aboutarabidopsis.jsp>. Acknowledgements: Dr. Bruce Smith

Anther (2 locules) Pistil

Dyad Tetrad Functional

2-Nucleate 4-Nucleate 8-Nucleate

(Re-done)

(Re-done)

(New research)