How Can Plants Choose the Most Promising Organs? - Communication in Plants: Neuronal Aspects of Plant Life - page 55

a b d

c

f g

e

Fig. 4.1. The two-shoot pea experimental system. a The seminal shoot of a germinating
pea seedling was removed. b Within3daystheremovedshootwasreplacedbythegrowth
of inhibited buds and they became two new shoots. c Within four additional days the
new shoots carried expanded leaves and were generally somewhat unequal. d Inequality
between the shoots increased. At the time the experiments shown in Fig. 4.2 were started
the wet-weight ratio of the smaller over the larger shoot was 0.37. e In some varieties the
smaller shoot actually died within 2 weeks. f Removal of the larger, dominant shoot before
the smaller shoot had died. The declining shoot survived and developed rapidly. Its average
fresh weight, shown in milligrams, did not differ much from that of an undisturbed dominant
shoot (in e ). g Dominance influences between shoots. Removing both the dominant shoot
and the upper part of the smaller shoot resulted in the growth of a bud in the axil of an
expanded leaf. This bud did not grow when the large shoot was left intact. (Based on Sachs
and Hassidim 1996)