The In Vitro Tetraploid Induction of Tangerine (Citrus nobilis Lour.) Using Colchicines.

Abstract

Seedless fruit is one of the criteria necessary to improve the quality of Simadu tangerine. The most effective method to obtain seedless triploid cultivars is hybridisation between tetraploid and diploid parents. The aim of this research was to obtain tetraploid Simadu tangerine planlet which would serve as parent to produced seedless Simadu tangerine. The experiment was conducted at Biology Cell and Tissue Laboratory of BB-Biogen and Micro Technique Laboratory of Agronomy and Horticulture Department, IPB, Bogor from January to August 2013. In vitro Simadu tangerine shoot-tips without leaves, lateral shoots without leaves and somatic embryos globular phase were treated with colchicines at four different concentrations (0%, 0.1%, 0.2%, and 0.3) for 3 hours (Shoot-tips), 6 hours (lateral shoots) and 1 hour (globular). The result of in vitro tetraploid induction of tangerine shoot-tip showed that colchicine treatments reduced growth of shoot-tip of Simadu Tangerine. The leaves of colchicines treated shoots were thicker than control. Leaves from control (0% colchicine) and 0.1% colchicine treated shoots had 8.67 and 18.25 chloroplasts per pair of guard cells. Leaves from 0.1% colchicine treated shoots had stomata sizes were larger than control shoots. Leaves from 0.1% colchicine treated shoots had stomata density was lower than control shoots. The tetraploid Simadu tangerine shoots were produced by the treatment of 0.1% colchicine. The result of in vitro tetraploid induction of tangerine shoot-tip showed that the shoots of colchicines treated were taller than control. The shoots of colchicines treated had leaves were wider than control. The colchicines treatments increased numbers of chloroplasts per stomata guard cell. Leaves from colchicine treated shoots had stomata sizes were larger than control shoots. Leaves from colchicine treated shoots had stomata density was lower than control shoots. The result of in vitro tetraploid induction of tangerine somatic embryos showed that colchicine treatments with high concentration increased abnormal planlet percentage. The tetraploid Simadu tangerine planlets were produced using 0.2% colchicine and 0.3% colchicine.