ISHS Acta Horticulturae 444: III International Symposium on Kiwifruit
UPTAKE, DISTRIBUTION OF RADIOACTIVITY AND RESPONSE OF KIWIFRUIT TISSUE TO 14C-CPPU |
| Authors: | J.G. Cruz-Castillo, D.J. Woolley, G.S. Lawes |
| Keywords: | cytokinin, fruit growth, growth regulators, Actinidia deliciosa, CPPU |
| Abstract:
'Hayward' fruit size response to CPPU (N-(2-chloro-4-pyridyl)-N-phenylurea) was significantly (P ≤ 0.05) enhanced by 30 g when applied in combination with 2,4-D + GA3. Uptake, distribution, and harvest residues of 14C-CPPU applied alone and combined with 2,4-D + GA3 were investigated. Forty eight hours after application highest radioactivity was recorded in the blossom end, and lowest in the inner pericarp and core. From 21 days after application until commercial harvest, the skin had the highest radioactivity (up to 80% of total) followed by the outer pericarp. The lowest radioactivity was found in the inner pericarp and core. Inclusion of 2,4-D + GA3 increased radioactivity in the outer pericarp after 21 days by 62 and 57% in the acetone soluble and insoluble fractions, respectively. At commercial harvest radioactive metabolites of CPPU averaged 6.1 and 4.7 ppb (fresh weight basis) for acetone soluble and insoluble fractions, respectively, with 90% present in the skin. | |
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