Effect of maleic hydrazide on endogenous cytokinin contents in lateral buds, and its possible role in flower bud formation on the Japanese pear shoot

• Published in: Scientia horticulturae 2001-02, Vol.87 (3), p.199-205
• Main Authors: Ito, Akiko, Hayama, Hiroko, Kashimura, Yoshiki, Yoshioka, Hirohito
• Format: Article
• Language: English
• Subjects: 2,3,5-Triiodobenzoic acid; Agronomy. Soil science and plant productions; Biological and medical sciences; Cytokinin; Economic plant physiology; Flower bud production; Fundamental and applied biological sciences. Psychology; Growth and development; Growth regulators; Japanese pear; Maleic hydrazide; Pyrus pyrifolia
• ISSN: 0304-4238; 1879-1018
• DOI: 10.1016/S0304-4238(00)00174-6

In order to elucidate the role of maleic hydrazide (MH, 1,2-dihydro-3,6-pyridazinedione; coline salt) in increasing flower bud formation on the Japanese pear, the effect of MH on cytokinin contents in the lateral buds of Japanese pear shoots were investigated. Foliar application of MH at 2600 mg l −1 increased zeatin, zeatinriboside, and isopentenyladenine levels in lateral buds though isopentenyladenosine concentration decreased. Application of 2,3,5-triiodobenzoic acid (TIBA), an inhibitor of polar auxin transport, also increased the endogenous cytokinin levels in lateral buds. It is supposed that these increases of cytokinin in lateral buds may be involved in the increase of flower bud production on the Japanese pear shoot. The increases of cytokinin induced by these chemicals may be caused via the depletion of the auxin level and/or the activity in shoot tissues.