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The joint action of phytochrome and alternating temperatures in the control of seed germination in Dactylis glomerata
Author(s) -
Probert R. J.,
Smith R. O.
Publication year - 1986
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.1986.tb02460.x
Subject(s) - phytochrome , germination , dactylis glomerata , irradiation , biology , far red , horticulture , red light , botany , poaceae , physics , nuclear physics
The promoting effect of light and alternating temperatures on the germination of seeds of three contrasting populations of Dactylis glomerata L. was studied. Irradiation treatments using broad band low irradiance light sources resulted in red/far‐red reversible effects, demonstrating the involvement of phytochrome in germination control. Reduction of germination by far‐red below the level of a dark control indicated the presence of high pre‐existing levels of the active form of phytochrome (P fr ) in some individuals. The capacity for dark germination at 21/11°C (12 h/12 h) was shown to be dependent on P fr . Although some individuals were capable of germination at constant temperatures following red irradiation, in most seeds germination was dependent on the presence of P fr and alternating temperatures. Some individuals responded to a single red irradiation, although a large proportion of seeds required high levels of P fr to be maintained for long periods. Previously published dose response curves for alternating temperatures and a measured dark reversion time of 48 h for P fr established by a single 60 min red irradiation, provided firm evidence of a direct correlation between the requirements for repeated irradiation and number of alternating temperature cycles.