Details

Autor(en) / Beteiligte

• Meier, S.
• Grand, L.F.
• Schoeneberger, M.M.
• Reinert, R.A.
• Bruck, R.I.

Titel

Growth, ectomycorrhizae and nonstructural carbohydrates of loblolly pine seedlings exposed to ozone and soil water deficit

Ist Teil von

• Environmental pollution (1987), 1990, Vol.64 (1), p.11-27

Ort / Verlag

Oxford: Elsevier Ltd

Erscheinungsjahr

1990

Quelle

Elsevier Journal Backfiles on ScienceDirect (DFG Nationallizenzen)

Beschreibungen/Notizen

• Loblolly pine ( Pinus taeda) seedlings from three full-sib families were exposed to 0, 50, 100 or 150 ppb ozone (O 3) (5 h/d, 5 d/week for 6 or 12 weeks). Soil water potential was maintained near pot capacity (−0.03 MPa) or soil was allowed to dry to approximately −1.0 MPa and resaturated. Chlorotic mottling and flecking of needles due to O 3 injury were observed for seedlings from all pine families. Soil water deficit lessened the intensity of O 3 symptoms, possibly due to stomatal closure. Exposure to O 3 and soil water deficit each resulted in less seedling volume growth and dry weight, and changed the nonstructural carbohydrate content of seedlings compared with controls. Increasing O 3 concentrations resulted in a linear reduction in foliar starch content but did and affect hexose or sucrose content. Soil water deficit resulted in less starch and soluble sugar contents in above- and below-ground plant parts compared with controls. Soil water deficit did not affect numbers or percentages of roots that formed ectomycorrhizal tips. A linear dose-response relationship between O 3 and ectomycorrhizae was observed. The number of ectomycorrhizal tips/cm long root and the percentage of feeder roots that formed ectomycorrhizae were lower as O 3 concentration increased. Overall, each stress alone caused less seedling growth and carbohydrate content compared with controls, but only O 3 was responsible for suppression of ectomycorrhizae.