Abstract Detail

Ecological Section

Augustiro, Wendee [1], Cantley, Jason [1], Chau, Marian [1], Barton, Kasey [2].

Relationships between anatomical leaf characteristics and photosynthetic abilities of Lipochaeta lobata, Melanthera integrifolia and their intergeneric hybrids.

Melanthera integrifolia and Lipochaeta lobata are two Hawaiian endemic plant species found on the island of O`ahu that form a naturally occurring intergeneric hybrid. M. integrifolia is a low growing herb adapted to low elevation coastal areas with thick fleshy leaves, whereas L. lobata is a subshrub without thickened leaves and is found at slightly higher elevations. These differences in leaf thickness between the two species may represent different adaptations to life along the coast and photosynthetic abilities in their respective microclimates. The hybrid L. lobata x M. integrifolia is often distinguished from the parental species by its intermediacy in external foliar characteristics. However, it is unclear how leaf trait characteristics are expressed in the hybrid and how well-adapted the hybrid individuals are in comparison to the parental species. To assess an aspect of fitness for L. lobata x M. integrifolia, we measured various anatomical leaf characteristics (i.e. thickness of epidermis, palisade parenchyma, and spongy mesophyll; leaf water content; SLA) as well as the photosynthetic abilities of each taxon. Cell layer thicknesses of L. lobata, M. integrifolia and the hybrid was compared with photosynthetic quantum yield (Y₀), nonphotochemical quenching (NPQ) and maximum electron transport rate (ETRm) of photosystem II. Results indicate that hybrid individuals exhibit a range of intermediate anatomical leaf trait characters and photosynthetic abilities in comparison to the parental species. These results suggest that perhaps L. lobata x M. integrifolia may be expressing phenotypic plasticity as a response to the environment during ontogenetic development in coastal microclimates.

Broader Impacts:

1 - University of Hawaii At Manoa, Botany, 3190 Maile Way, Room 101, Honolulu, HI, 96822, USA
2 - University of Hawaii At Manoa , Botany, 3190 Maile Way, Room 101, Honolulu, HI, 96822, USA

Keywords:
none specified

Presentation Type: Poster:Posters for Sections
Session: P
Location: Grand Salon A - D/Riverside Hilton
Date: Monday, July 29th, 2013
Time: 5:45 PM
Number: PEC010
Abstract ID:336
Candidate for Awards:None