Abstract Detail

Development and Structure

Appleton, Andrea [1], Kramer, Elena [2].

A developmental and transcriptional exploration of staminode evolution in Loasaceae.

The importance of the evolution of flowers and the breadth of morphological diversity across angiosperms cannot be overstated. In addition to variation in the typical four floral organs (sepals, petals, stamens, and carpels), the evolution of novel organ identities is notable. One such novel structure is the staminode, which is a stamen that has evolutionarily become sterile. Staminodes are present in many lineages and have evolved an array of forms in response to selection for alternative functions. Staminode morphology and pollination biology have been well-characterized, but little is known about the genetic underpinnings of these structures despite their potential in illuminating how morphological novelty and diversity evolve. Staminodes in Loasaceae are particularly striking in their sheer amount of morphological and functional variation. Even the same flower can host multiple types of staminodes, such as those of subfamily Loasoideae, which contain staminodial nectar scales and filamentous staminodes in addition to fertile stamens. Further, Loasaceae is hypothesized to contain multiple independent origins of staminodes between and within subfamilies, including one at the base of Loasoideae, one in Gronovoideae, and at least six in Mentzelioideae, making it an ideal family in which to investigate modifications of the stamen developmental program that produce staminodes. Here, we present a detailed developmental study of staminode morphology of Aosa rupestris (Loasoideae) and complement it with the identification of floral MADS box genes - the first step towards understanding the putative genetic origins of staminodes in Loasaceae.

1 - Harvard University, Organismic and Evolutionary Biology, Cambridge, MA, United States
2 - Harvard Univ., OEB, 16 Divinity Avenue, BL 1119, Cambridge, MA, 02138, United States

Keywords:
androecium
floral evolution
Floral Development
morphology
Loasaceae
staminode.

Presentation Type: Poster
Number: PDS004
Abstract ID:242
Candidate for Awards:Developmental and Structural Section best poster,Developmental and Structural Section Graduate Student Registration Award