二、太湖莼菜的生物学特性(一)生长与发育莼菜有种子,种子可以萌发生长成植株,但在栽培中,都采用无性繁殖。莼菜的营养生长和生殖生长在时间上相互交叉,不能截然分开。营养生长可划分为4个阶段:1.荫发阶段:3月下旬,平均气温15℃时,地下茎与水中茎开始萌发新芽,水面出现浮叶。随着主茎预芽萌发,侧枝顶芽也相继萌发、伸长,并放出小叶,叶柄伸长,叶片浮出水面。同时,匍匐 Second, the biological characteristics of Taihu water spinach (a) growth and development of water spinach seeds, the seeds can germinate and grow into plants, but in the cultivation, the use of asexual reproduction. Ipomoea vegetative and reproductive growth in time cross each other, can not be completely separated. Nutritional growth can be divided into four stages: 1. Shade stage: in late March, the average temperature of 15 ℃, underground stems and stems began to sprout water shoots, floating leaves appear on the surface of the water. With the pre-bud germination of the main stem, lateral buds also have germination, elongation, and release of leaflets, petiole elongation, leaves surfaced. At the same time, creeping