Abstract Detail

Anatomy and Morphology

Khojayori, Farahnoz [1], Zhang, Jingbo [2], Zhang, Wenheng [3].

Floral ontogeny of Krameria lanceolata Torrey (Krameriaceae).

Floral zygomorphy is thought to be an adaptive trait, associated with highly specialized pollination strategies. In Krameria Loefl., the only genus of Krameriaceae, the showy zygomorphic floral display is mainly established by the petaloid sepals, a flag comprised of fused dorsal and lateral petals, and the ventral petals—modified oil-glands that associate with the oil-bee pollinators of the New World. Floral zygomorphy is also observed in the androecium and gynoecium in Krameria flowers. The zygomorphic androecium is established by four stamens that are fused basally—with the two dorsal anthers shorter than the two lateral anthers; the single ventral stamen is absent from mature flowers. In the zygomorphic gynoecium, the dorsal carpel of the bicarpellate gynoecium is aborted. The ontogeny of Krameria flowers to illustrate the early floral development, however, is largely lacking, particularly in regard to the fusion within the androecium and corolla whorls, and the abortion of the ventral stamen. Here, we utilized scanning electron microscopy (SEM) to elucidate on the floral development of K. lanceolata. Our preliminary results showed that the five petal primordia emerge separately, followed by the four separate stamens and the two fused carpels. This suggests that the fusion of the dorsal and adjacent lateral petals occurred later during development. Additionally, the two dorsal and two lateral stamens initiate simultaneously, but the ventral stamen never arises, suggesting it is fully suppressed in early development. Our results help provide a better understanding of the development of floral zygomorphy in Krameria, which will be the foundational work to start shedding light on the developmental and genetic mechanisms responsible for their unique floral morphologies.

1 - Virginia Commonwealth University, Biology, 1000 West Cary Street, Richmond, VA, 23284, United States
2 - Department Of Biology, Virginia Commonwealth University, 1000 West Cary Street, Life Science Building 336, Richmond, VA, 23284, United States
3 - Virginia Commonwealth University, Department Of Biology, 1000 W Cary Street, Richmond, VA, 23284, United States

Keywords:
Floral development
SEM
floral morphology
Krameria lanceolata
Zygophyllales
Floral zygomorphy
Organ Fusion 
Connate.

Presentation Type: Poster
Session: P, Anatomy and Morphology
Location: Grand Ballroom - Exhibit Hall/Mayo Civic Center
Date: Monday, July 23rd, 2018
Time: 5:30 PM This poster will be presented at 6:15 pm. The Poster Session runs from 5:30 pm to 7:00 pm. Posters with odd poster numbers are presented at 5:30 pm, and posters with even poster numbers are presented at 6:15 pm.
Number: PAM016
Abstract ID:856
Candidate for Awards:Developmental and Structural Section best poster