Investigating the developmental mechanisms responsible for within-plan variation in Halenia deflexa

Abstract

(From "Introductory Remarks") My honours research contributes to answering the large question, “Are the developmental mechanisms that result in variation in spur length among flowers within individuals of H. deflexa the same as those that produce variation in spur length among species within the genus Halenia?” This question is beyond the scope of a single honours project, so my objective was to address the first part of the question. I aimed to describe the floral developmental adjustments responsible for the within-plant variation of nectar spur lengths in Halenia deflexa. Specifically, my goals were (1) to develop methods for clearing, staining, and imaging preserved H. deflexa floral tissue, and (2) to describe what cellular changes are causing these variations in nectar spur lengths, whether it’s due to the size, shape, or number of cells, or some combination of factors. Historically within-plant variation has been mostly seen as inconvenient, an irrelevant detail obscuring the mean (Herrera 2009). Recently, however, within-plant variation is increasingly being investigated as a possible target for selection. This research could be the first step towards uncovering some important evolutionary significance in an under-appreciated trait. If within-plant variation is indeed a blueprint for diversification, then maybe it can give us a glimpse into the evolutionary trajectory of plants.