An experimental analysis and comparison of three rhythms of movements in bean (Phaseolus vulgaris L.)

Three types of rhythmic movements of Phaseolus vulgaris L. (pole beans) were examined collectively and their characteristics compared. Although the ultradian rhythms of shoot circumnutation and leaf movement, as well as the circadian rhythm of leaf movement, occurred simultaneously, each rhythm could be expressed independently of the other two. Shoot circumnutation and ultradian leaf movements displayed the same period (80 min at 25 degrees C and Q10 congruent to 2), while the period of the circadian leaf movements was not temperature dependent (Q10 congruent to 1). Interaction into the plant between two ultradian rhythms (shoot circumnutation and ultradian leaf movement) with the same period and coexistence in the pulvinus of an ultradian with a circadian rhythm are discussed.