大棚里种的黄瓜、西红柿、茄子、辣椒等菜，具有生长快、成熟早、产量高、经济效益好等优点。“好种出好苗，好苗产量高”，于是许多菜农就到大棚里选留菜种。其实这是不可取的。因为大棚里的蔬菜生长期温度与外界自然的温度不大一致，大棚里的蔬菜抗逆性差，授粉程度低，种子? Greenhouses in the cucumber, tomato, eggplant, pepper and other vegetables, with fast growth, early maturity, high yield, good economic returns. “Good kind of good seedlings, good seedlings high yield,” so many farmers went to the greenhouse to stay for food. In fact, this is not desirable. Because the greenhouses in the vegetable growing temperature is not the same as the natural temperature of the outside world, greenhouses in the poor resistance of vegetables, pollination is low, the seeds?