甜叶菊(Stevia vebaudiana)为多年生草本植物,原产南美洲巴拉圭。叶子含葡糖甙,甜味浓,可用于制药片糖衣、糖果点心等,是低热量的糖,吃了不使人肥胖,也是糖尿病患者食糖的代用品,经济价值较高。引入我国以后:南北方都有种植,但在北方开花结籽较迟,种子不能正常成熟。为此,我们采用短光照处理植株,已结出成熟种子。具体做法是:4月上旬浸种催芽,在室内播种,当时室温为15℃左右,由于温度低,小苗生长缓慢,5月以后随气温上升,生长渐快,疏苗定植。6月末气温20℃左右,苗高约25～30厘米,苗龄70～80天(7月1日)时每天进行10个小时短日照处理。在处理第10天,解剖枝顶部和叶腋的芽,看到花芽形成。在处理第20天(7月20日)花开放,到7月末 Stevia vebaudiana is a perennial herb native to Paraguay, South America. The leaves contain glucoside, sweet and concentrated, can be used for pharmaceutical tablets sugar-coated, confectionery, etc., is a low-calorie sugar, eat not to make people fat, but also diabetic substitutes, higher economic value. Since the introduction of our country: both northern and southern planting, but in the northern flowering and seed later, the seeds can not be normal maturity. To this end, we treated plants with short light and weeded out mature seeds. Specific practices are: early April soaking germination indoors sowing, when the room temperature is about 15 ℃, due to low temperature, slow growth of seedlings, with the temperature rise after May, grow faster, sparse seedlings planted. At the end of June, the temperature is around 20 ℃, the shoot height is about 25-30 cm, and the seedling age is 70-80 days (July 1). At the 10th day of treatment, buds were dissected at the top of the shoots and axils of the leaves, and flower bud formation was seen. On the 20th day of the treatment (July 20), flowers bloom until the end of July