|
|
||||||||
Dep. of Horticulture, Forestry, and Recreation Resources, 2021 Throckmorton Plant Sciences Center, Kansas State University, Manhattan, KS 66506 USA
bhuang{at}oz.oznet.ksu.edu
Cool-season turfgrasses are frequently subjected to heat and drought stresses during summer months. This study was conducted to determine physiological responses of Kentucky bluegrass (Poa pratensis L.) to drought and heat alone or together, and the effects of drought preconditioning on plant responses to subsequent heat stress. Kentucky bluegrass (cv. Mystic) was subjected to drought and/or heat stress (35°C/30°C, day/night) in growth chambers for 40 d. Canopy photosynthetic rate (Pn) and leaf photochemical efficiency (Fv/Fm) decreased under drought and heat stress. The decline in Pn was more severe under heat than under drought stress during the first 12 d of treatment. The reduction in Fv/Fm ratio was more severe under drought stress than under heat stress after 20 d of treatment. The combined heat and drought stresses (H+D) caused more dramatic reductions in Pn and Fv/Fm than either heat or drought alone, starting at 3 and 9 d after treatment, respectively. Drought or heat alone, or H+D, significantly reduced root dry weight. However, reduction was more severe under heat alone than under drought stress, particularly in the top 20 cm of soil. Drought preconditioning enhanced plant tolerance to subsequent heat stress but had no influence on plant tolerance to H+D. Drought-preconditioned plants maintained higher water status, stomatal conductance, and transpiration rate, and had significantly higher Pn and root dry weight than non-preconditioned plants during subsequent heat stress. No significant difference in Fv/Fm was observed between drought-preconditioned and non-preconditioned plants under either heat alone or H+D. The results indicated that simultaneous drought and heat stresses were more detrimental than either stress alone. Drought preconditioning could improve Kentucky bluegrass tolerance to subsequent heat stress.
Abbreviations: Fv/Fm, photochemical efficiency or chlorophyll fluorescence
w, leaf water potential 
, osmotic potential
p, turgor pressure gs, stomatal conductance LSD, least significance difference Pn, canopy photosynthetic rate
This article has been cited by other articles:
![]() |
S. Natarajan and J. S. Kuehny Morphological, Physiological, and Anatomical Characteristics Associated with Heat Preconditioning and Heat Tolerance in Salvia splendens J. Amer. Soc. Hort. Sci., July 1, 2008; 133(4): 527 - 534. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. K. Dettman-Kruse, N. E. Christians, and M. H. Chaplin Predicting Soil Water Content through Remote Sensing of Vegetative Characteristics in a Turfgrass System Crop Sci., March 19, 2008; 48(2): 763 - 770. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. Su, D. J. Bremer, S. J. Keeley, and J. D. Fry Effects of High Temperature and Drought on a Hybrid Bluegrass Compared with Kentucky Bluegrass and Tall Fescue Crop Sci., September 1, 2007; 47(5): 2152 - 2161. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. M. O'Neill, J. F. Shanahan, and J. S. Schepers Use of Chlorophyll Fluorescence Assessments to Differentiate Corn Hybrid Response To Variable Water Conditions Crop Sci., February 1, 2006; 46(2): 681 - 687. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. J. Bremer and J. M. Ham MEASUREMENT AND PARTITIONING OF IN SITU CARBON DIOXIDE FLUXES IN TURFGRASSES USING A PRESSURIZED CHAMBER Agron. J., March 1, 2005; 97(2): 627 - 632. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. S. Ebdon and K. L. Kopp Relationships between Water Use Efficiency, Carbon Isotope Discrimination, and Turf Performance in Genotypes of Kentucky Bluegrass during Drought Crop Sci., September 1, 2004; 44(5): 1754 - 1762. [Abstract] [Full Text] [PDF] |
||||
![]() |
Y. Jiang and B. Huang Osmotic Adjustment and Root Growth Associated with Drought Preconditioning-Enhanced Heat Tolerance in Kentucky Bluegrass Crop Sci., July 1, 2001; 41(4): 1168 - 1173. [Abstract] [Full Text] [PDF] |
||||
![]() |
Y. Jiang and B. Huang Drought and Heat Stress Injury to Two Cool-Season Turfgrasses in Relation to Antioxidant Metabolism and Lipid Peroxidation Crop Sci., March 1, 2001; 41(2): 436 - 442. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| The SCI Journals | Agronomy Journal | Vadose Zone Journal | |||
| Journal of Natural Resources and Life Sciences Education |
Soil Science Society of America Journal | ||||
| Journal of Plant Registrations | Journal of Environmental Quality |
The Plant Genome | |||