Shoot and root formation on cut pieces of viviparous seedlings of a mangrove, Kandelia candel (L.) druce

Abstract

For re/afforestation of mangroves in tropical countries, the lack of viviparous seedlings to plant is a current prevailing problem. To attain the maximum use of the viviparous seedling, the cut-piece method has been proposed by some Thai foresters. In our experiment, a single viviparous seedling of Kandelia candel was partitioned into lengths of 1, 2, 3, 5, and 10 cm. Each cut piece was planted in a laboratory, and the formation of roots and shoots was checked for 168 days. The 1 cm treatment showed the lowest rate of shoot emergence (1.1–3.3%). Among the cut pieces originating from the upper position on the seedling, the ratio of shoot formation was higher (63.3–93.8%) from the cut pieces containing a plumule of the viviparous seedlings. The ratio was lower (0–26.6%) in the cut pieces containing no plumule. Among the cut pieces originating from a lower position, the ratio was higher (34.2–50.0%) in cut pieces containing no radicle of the seedlings. In other cut pieces containing a radicle, no shoot formation was observed except in the 10 cm treatment (26.7%). The ratio of multiplication, which means the number of grown cut pieces produced per single viviparous seedling, was highest in the 3 cm treatment (206.7%), followed by the 2 cm treatment (200.0%). The efficiency and problems in this method are discussed.