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Dormancy and Apical Dominance in Potato Tubers
H. David Michener
American Journal of Botany
Vol. 29, No. 7 (Jul., 1942), pp. 558-568
Published by: Botanical Society of America, Inc.
Stable URL: http://www.jstor.org/stable/2437105
Page Count: 11
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When the intact potato tuber begins to grow after its rest period, one or more apical buds grow, but the lateral buds usually fail to grow. If, however, lateral buds and apical buds are cut out and grown separately, both start to grow at the same time. In non-dormant tubers, any large bud usually inhibits growth of smaller ones. In non-dormant tubers, the auxin concentration is high in the large apical buds, lower in the tissue below them, and lowest in the tissue below the lateral buds. In tubers in which apical dominance has been destroyed by treatment with ethylene chlorohydrin, application of indoleacetic acid to the apex of the tuber causes inhibition of the lateral buds. In other words, apical dominance can be produced artificially by applying indoleacetic acid to the apex of the tuber. Therefore, it is probably auxin produced by the apical buds which correlates growth of apical and lateral buds when the tuber begins to grow after its rest period. When the tuber is treated with ethylene chlorohydrin, much of its auxin disappears. Special experiments show an increase in auxin destruction at the time. The auxin reappears within two or three days after the end of treatment. It is suggested that auxin inhibits bud growth in the dormant tuber, and that removal of the auxin by the action of ethylene chlorohydrin permits growth to proceed. The disappearance of apical dominance which follows ethylene chlorohydrin treatment is also a result of the auxin destruction which takes place during the treatment.
American Journal of Botany © 1942 Botanical Society of America, Inc.