© 1996 Heron Publishing—Victoria, Canada
Non-nutritional stress acclimation of mycorrhizal woody plants exposed to drought
F. T. Davies, Jr. (1), S. E. Svenson (2), J. C. Cole (3), L. Phavaphutanon (1), S. A. Duray (1), V. Olalde-Portugal (4), C. E. Meier (5) and S. H. Bo (6)
1. Department of Horticultural Sciences, Texas A&M University, College Station, TX 77843-2133, USA / 2. North Willamette Research and Extension Center, Oregon State University, Aurora, OR 97002-9543, USA / 3. Department of Horticulture, Oklahoma State University, Stillwater, OK 74078-6027, USA / 4. CINVESTAV Plant Biology Institute, Apdo. Postal 629, Irapuato, GTO, Mexico / 5. USDA Forest Service, Southern Forest Experiment Station, Pineville, LA 71360, USA / 6. Myanmar Agricultural Service, 72–74 Shwedagon Pagoda Rd., Yangon, Union of Myanmar / Received October 25, 1995
Summary
Mycorrhizal enhancement of drought resistance of two woody plant species, loblolly pine (Pinus taeda L.) and rose (Rosa hybrida L. cv. Ferdy), occurred independently of phosphorus nutrition. Mycorrhizae tended to alter root morphology and carbon allocation
patterns of shoots and roots. Increased drought resistance of mycorrhizal plants was in part attributed to drought-induced
colonization by mycorrhizae and the ability of the mycorrhizal plants to maintain high transpiration rates as a result of
greater lateral root formation and lower shoot mass (in ectomycorrhizal loblolly pine), and a higher root/shoot ratio and
leaf abscission (in endomycorrhizal roses). Neither the endo- nor ectomycorrhizal symbionts affected osmotic adjustment of
droughted plants.
Keywords:
extraradical hyphae, gas exchange, Pinus taeda, phosphorus nutrition, Rosa hybrida.
