Ectomycorrhizae influences on CO/sub 2/ exchange and carbon allocation in Pinus

Thesis/Dissertation · Sat Jan 01 04:00:00 EST 1983

OSTI ID:6271159

Kidd, F A

Although the importance of mycorrhizal fungi in nutrient ion absorption is relatively well documented, little is known concerning the energy cost required of the host plant for the maintenance of the nurient-absorbing area provided by the mycorrhizae. The objective of this research was to gain further knowledge on how the basic physiological processes of photosynthesis and respiration, as well as allocation of carbon compounds, may be stimulated in host Pinus seedlings through source-sink relationships resulting from mycorrhizae. Seedlings of four Pinus species with 50-75% short root infection by three mycorrhizae species had a rate of net photosynthesis 3X as great as that of noninfected plants. The increase in CO/sub 2/ fixation appeared linear with respect to fungal infection as percentage short root infection increased from zero to 75%. When other parameters of seedling growth and morphology, i.e. shoot and root dry weight, dark respiration rates, and foliar concentration of nitrogen, were correlated with net photosynthetic rate, only mycorrhizae infection demonstrated a statistically significant (P < 0.05) influence on increasing host CO/sub 2/ exchange. Partitioning of current photosynthate was examined by pulse-labeling Pinus taeda L. with /sup 14/CO/sub 2/ at each of six time intervals. Although the stimulation of photosynthesis and allocation of current photosynthate to the root system by mycorrhizae formation was consistent with the source-sink concept of sink demand, foliar N and P concentrations were also greater in mycorrhizal plants.

• OSTI ID: 6271159
• Country of Publication: United States
• Language: English

Related Subjects

550500* -- Metabolism
59 BASIC BIOLOGICAL SCIENCES
BIOLOGICAL EFFECTS
CARBON COMPOUNDS
CARBON CYCLE
CARBON DIOXIDE
CARBON OXIDES
CHALCOGENIDES
CHEMICAL REACTIONS
CLEARANCE
CONIFERS
EXCRETION
MYCORRHIZAS
OXIDES
OXYGEN COMPOUNDS
PHOTOCHEMICAL REACTIONS
PHOTOSYNTHESIS
PINES
PLANTS
RESPIRATION
SYMBIOSIS
SYNTHESIS
TREES
UPTAKE