Circadian Rhythms in Plants

Cycles in botany, dendrochronology, tree, plant and crop growth

Circadian Rhythms in Plants

Postby K. David » 20 Aug 2010, 18:24

History of Biorhythms


Records from as far back as the fourth century, BC show that Androsthenes, the scribe for Alexander the Great who recorded descriptions of his marches, documented movements in the leaves of the tamarind tree. The leaves opened in the day and closed at night in a diurnal 'sleep' pattern. French scientist and astronomer, Jean Jacques D´Ortous de Mairan, performed tests in 1729 that showed that leaf patterns of the heliotrope plant continued to open by day and close by night even when kept on total darkness, proving the existence of an internal biological rhythm.

Related Studies:

Circadian Rhythms (cycles lasting about a day) that were known to exists in plants were also observed in animals. Early in the 1900s, Karl von Frisch and Ingeborg Beling noticed that bees visited flowers at certain times of the day even when placed in a man-made feeding station where nectar and daylight were absent. This demonstrated the presence of endogenous biological rhythms (originating within). Auguste Forel also found accurate test results on the biological systems of bees in 1910 and his work added to the interest in circadian rhythms. Sutherland Simpson and J.J. Galbraith made significant observations in mammalian behavior in 1906 while altering the environmental light-dark cycle. Gustav Kramer and Klaus Hoffmann studied the internal clocks of migrating birds in the 1950s and Colin Pittendrigh demonstrated that their internal clocks remained fixed regardless of environment. Results in the study of many types of circadian Rhythms are now pervasive.

K. David Katzmire
K. David
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Joined: 05 Aug 2010, 04:08
Location: Pennsylvania, USA

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