Endogene Jahresperiodik der Blattbewegungen zweier Oxalis‐Arten

• Published in: Physiologia Plantarum
• Main Author: MÜLLER‐HAECKEL, AGNES
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 1975
• Subjects: Arctic
• Online Access: http://dx.doi.org/10.1111/j.1399-3054.1975.tb03900.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1399-3054.1975.tb03900.x; https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1399-3054.1975.tb03900.x

Abstract Under natural light‐dark changes at the Arctic Circle special behaviour was observed in the leaf movement of Oxalis regnellii and Oxalis acetosella : (1) Advancing in the beginning of leaf rising. (2) Prolonging of the duration of day position. (3) Increasing positive phase‐andle differences. (4) Prolonging of the duratin of the daily moving‐time. From January to April all these features were running back. The winter behaviour has also been shown in artificial light‐dark changes (12:12), when plants were taken in the trial before mid winter. The reactions did not occur if the plants were put into artificial light conditions after mid winter. Criterions for an endogenous annual periodicity and its possible annual Zeitgebers under natural light‐dark changes are discussed. The positive correlation between the length of day position and the length of day‐time in the summer respectively the length of night‐time in the winter, as well as positive phase‐angle difference in spring and in autumn/winter, are judged as a criterion for a second oscillator.