Throughout the specification, the terms "plant tissue culture technique," "plant tissue culture," or "tissue culture" may be interchanged with one another. The term "plant tissue culture technique," as used herein, means that a series ofoperational steps is applied to supply plant organs, plant tissues or plant cells with growth conditions (e.g. light, temperature, nutrient, plant hormones or plant growth regulators etc.) under sterile condition to multiply or regenerate the plantorgans or the whole plants.