Temperature and photoperiodic control of developmental responses in climatic races of Mimulus |
| |
Authors: | CLINE M G; AGATEP A O |
| |
Institution: | Division of Biology, California Institute of Technology Pasadena, California 91109, U.S.A. |
| |
Abstract: | Two strongly differentiated climatic races of the Mimulus cardinalis-lewisiicomplex were grown at a variety of temperatures (327°C)and photoperiods (8 and 16 hr) under controlled environmentalconditions. M. cardinalis (the lowland race, 400 m) and M. lewisii(the sub-alpine race, 3200 m) were found to differ in theirphysiological responses to the varied environments in severalsignificant ways: 1) At 27°C (16 hrphotoperiod), M. lewisiisustained 100% mortality in contrast to the substantial growthand flowering of M. cardinalis under these conditions; 2) In8 hr photoperiods at all temperatures, there was little growthand no flowering in M. lewisii whereas there was considerablegrowth at all temperatures, and flowering at 23 and 27°Cin M. cardinalis; 3) At low temperatures (715°C),16 hr photoperiods, flowering occurred a week or two earlierin M. lewisii than in M. cardinalis. The lowland race has asignificantly wider temperature and photoperiodic tolerancethan has the sub-alpine race. Applications of gibberellic acidto rosette Mimulus plants under non-inductive conditions (15°C,8 hr photoperiod) promoted vigorous stem elongation withoutflowering. The application of steroids, other hormones and metaboliteshad no observable effects.
1Present address: Faculty of Botany, Ohio State University,Columbus, Ohio, U.S.A. (Received March 16, 1970; ) |
| |
Keywords: | |
本文献已被 Oxford 等数据库收录! |
|