Abstract Detail

Systematics

Ickert-Bond, Stefanie [1], Lutz, Sue [2], Wen, Jun [2].

Leaf anatomy and micromorphology of the New World Vitis: Implications for taxonomy and evolutionary biome shifts.

Ongoing studies on phylogeny reconstruction of the economically important grape genus Vitis have established that the North American and Neotropical species of Vitis subgenus Vitis form a clade (except for V. californica). Species delimitation within North American subgenus Vitis has been difficult due to hybridization and/or clinal variation within species. North American and the Neotropical species of subgenus Vitis occupy diverse habitats, but they are especially diverse in the mesic forest areas in the southeastern U.S. and the xeric scrublands in southwestern North America (e.g., the Edwards Plateau of Central Texas and adjacent areas). We examined the c. 18 species of Vitis subgenus Vitis in the New World for leaf anatomical and micromorphological characters using light and scanning electron microscopy in the context of habitat shifts and taxonomy. Characters of taxonomic importance include trichome type; trichome distribution; stomata morphology; mesophyll organization and midrib vascularization. Vitis labrusca is shown to be more closely related to V. aestivalis than to V. mustangensis and V. shuttleworthii with the former two lacking a ridge above the midvein, and having four distinct bundles in the midvein, and raised stomates. The highly variable Vitis cinerea has been treated to consist of five varieties. Our study does not support a close relationship of taxa in the Vitis cinerea complex based on leaf anatomy and micromophology. Vitis cinerea var. helleri (= V. berlandieri) is easily distinguished from typical V. cinerea based on the increased palisade layer height up to 1/2 of the leaf height in cross section and lack of long curly, unicellular trichomes. Vitis cinerea var. baileyana and var. floridana have similar trichome morphology and leaf anatomy. Vitis mustangensis and V. shuttleworthii share a protruding stomatal apparatus abaxially and highly papillose epidermal cells adaxially. Vitis californica, V. arizonica, and V. girdiana all have an airy spongy layer, two rows of cells in the parenchyma bridge of tertiary veins, and striate subsidiary cells. Leaf anatomical differences associated with biome shifts are hypothesized with xeric species possessing a spongy layer with large air spaces and well-developed, large vascular bundles, and the Neotropical rainforest species V. tiliifolia having thin leaves with a poorly-differentiated mesophyll and hyathodes adaxially.

1 - University Of Alaska Museum Of The North, Herbarium (ALA) And Dept. Of Biology And Wildlife, University Of Alaska Fairbanks, 907 Yukon Dr., Fairbanks, AK, 99775, USA
2 - Smithsonian Institution, Botany, MRC-166 National Museum Of Natural History, 10th St. & Constitution Ave., NW, MRC 166, Washington/DC, N/A, 20013-7012, USA

Keywords:
grapes
Vitis
Vitaceae
leaf anatomy
micromorphology
biome shifts
taxonomy
New World.

Presentation Type: Poster
Session: P, Systematics Section/ASPT Posters
Location: Exhibit Hall/Savannah International Trade and Convention Center
Date: Monday, August 1st, 2016
Time: 5:30 PM This poster will be presented at 5:30 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: PSY021
Abstract ID:189
Candidate for Awards:None