Effects of certain growth regulators on the senescence of tea and coffee leaves
Detached fully expanded mature leaves or the first open leaf of a dormant or growing shoot of the tea cv. TV-20 were dipped (via petioles) in IAA, GA3 or kinetin solutions, each at 20 mg/litre. In some cases leaf discs were cut and floated on kinetin solution. The leaves were held in darkness. With arabica coffee, young growing leaves, fully expanded mature leaves, pre-senescent or senescent leaves were examined for chlorophylls, DM and peroxidase activity. Discs from fully expanded coffee leaves were floated in solutions of IAA, GA3, kinetin or ABA, each at 10 mg/litre. The fully expanded mature tea leaves did not show any chlorophyll loss even after 12 days in darkness, whereas the first open leaf from a growing shoot senesced slowly and that from a dormant shoot senesced rapidly. GA3 hastened senescence in mature tea leaves but retarded it in coffee. (Hort. Abst. 57(8):6758. 1987)
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Format: | biblioteca |
Published: |
1985
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Subjects: | COFFEA ARABICA, CAMELLIA SINENSIS, HOJAS, ESTIMULANTES DEL CRECIMIENTO, SENESCENCIA, |
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Summary: | Detached fully expanded mature leaves or the first open leaf of a dormant or growing shoot of the tea cv. TV-20 were dipped (via petioles) in IAA, GA3 or kinetin solutions, each at 20 mg/litre. In some cases leaf discs were cut and floated on kinetin solution. The leaves were held in darkness. With arabica coffee, young growing leaves, fully expanded mature leaves, pre-senescent or senescent leaves were examined for chlorophylls, DM and peroxidase activity. Discs from fully expanded coffee leaves were floated in solutions of IAA, GA3, kinetin or ABA, each at 10 mg/litre. The fully expanded mature tea leaves did not show any chlorophyll loss even after 12 days in darkness, whereas the first open leaf from a growing shoot senesced slowly and that from a dormant shoot senesced rapidly. GA3 hastened senescence in mature tea leaves but retarded it in coffee. (Hort. Abst. 57(8):6758. 1987) |
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