Abstract Detail

Pteridological Section/AFS

Nishida, Keisuke [1], Hanba, Yuko [2].

Low mesophyll CO₂ conductance of ferns relates to their mesophyll traits.

On the process of photosynthesis, CO₂ diffuses from the atmosphere to the chloroplast, through stomatal pores and leaf mesophyll. In recent years, there are increasing evidences showing that mesophyll conductance for CO₂ diffusion (g_m) limits leaf photosynthesis as well as, or even more than, stomatal conductance (g_s). Generally, g_s of ferns are lower than those of mainly seed plants, because of their low stomatal frequency. Although g_m was widely reported in seed plants, g_m of ferns has not been reported yet. We selected five temperate fern species from different habitats, Adiantum pedatum, Pteridium aquilinum, Dryopteris erythrosora, Lygodium japonicum, Thelypteris dentate, and estimated their g_m using stable carbon isotope method. Then, the mesophyll anatomies of fronds were observed using light microscope and transmission electron microscope to estimate their effects on g_m. All ferns used in this study have lower g_m than typical seed plants, irrespective of their habitats. Ferns used in this study had chloroplast in epidermal cells, which differs from typical seed plants. Ferns did not have well-marked palisade tissue. Chloroplasts of ferns were bigger and fewer than those of seed plants. As a result of these anatomical traits, S_c, surface area of chloroplast facing to interceller air space, of ferns were lower than those of seed plants. If our data were plotted together with the data of seed plant in the previous studies, g_m values were positively correlated with S_c, which suggests that low S_c of ferns was an important factor that explains why g_m of ferns are lower than those of seed plants.

Broader Impacts:

1 - Kyoto Institute of Technology, Materials and Life Science, 1, Hashigami-cho, Mathugasaki,Sakyo-ku, Kyoto, 606-8585, Japan
2 - Kyoto Institute of Technology, Applied Biology, 1, Hashigami-cho, Mathugasaki,Sakyo-ku, Kyoto, 606-8585, Japan

Keywords:
 Ferns
 Pteridophyte
 Photosynthesis
 Mesophyll conductance
 Mesophyll anatomy.

Presentation Type: Poster:Posters for Sections
Session: P
Location: Grand Salon A - D/Riverside Hilton
Date: Monday, July 29th, 2013
Time: 5:30 PM
Number: PPD005
Abstract ID:602
Candidate for Awards:None