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Some Metabolic Phenomena of Kentucky Bluegrass Under High Temperature 1
Author(s) -
Watschke T. L.,
Schmidt R. E.,
Carson E. W.,
Blaser R. E.
Publication year - 1972
Publication title -
crop science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.76
H-Index - 147
eISSN - 1435-0653
pISSN - 0011-183X
DOI - 10.2135/cropsci1972.0011183x001200010030x
Subject(s) - photosynthesis , photorespiration , poa pratensis , respiration , biology , carbon dioxide , oxygen , botany , compensation point , zoology , horticulture , poaceae , ecology , chemistry , organic chemistry , transpiration
Plugs of 10 Kentucky bluegrass ( Poa pratensis L.) strains grown in a controlled environmental growth chamber for 4 weeks at 23 to 15 C, and these temperatures were shifted to 35 to 25 C for 4 additional weeks. Foliar production and carbohydrates were reduced rapidly at high temperatures. By the end of the 3rd week these reductions decreased as threshold carbohydrate levels were apparently approached. Photosynthesis differed among the strains at 35 C in normal air. Low oxygen concentrations inhibited photorespiration and caused nearly two‐fold increases in net photosynthesis. Dark respiration, measured with CO 2 ‐free air, differed among the strains. Carbon dioxide compensation points were measured in a closed system and did not differ at 35 C. Bluegrasses with best growth at high temperatures generally had higher photosynthesis and lower respiration (both light and dark) than grasses with poor growth at high temperature. Management periods can influence tolerance; however, bluegrasses with genetically high photosynthetic efficiency should be selected for use in areas of high temperature stresses.