Spiral feedback oscillations of growing hypocotyl with radicle inPisum sativum L.

Cinematographic records of longitudinal growth showed that hypocotyl with radicle in Pisum sativum L. undergoes spiral oscillations during growth. This phenomenon can be characterized by the following time-space limits: Curvature of the hypocotyl with radicle takes place always in the zone of most rapid elongation (Fig. 2, 8). Maximum deflections of the root tip from a straight positive geotropic direction of growth correspond to the time when the maximum growth rates were demonstrated (Table 4, Fig. 8). Shift of zones of maximum elongation proceeds in a spiral path, acropetally to the region of the root tip; as may be seen from the results obtained by studying the growth of roots of perennial (woody) plants this mechanism is preserved throughout ontogeny ( Head 1965). When studying these self-regulating mechanisms the author suggests to use the principles valid for control systems with feedback as a mechanism eliminating errors.