生菜又名叶用莴苣,是菊科莴苣属一年生或二年生草本植物,主要有散叶生菜和结球生菜两大类,其中结球生菜在当地为一种特种蔬菜。张掖市位于河西地区中部,是甘肃省最大的蔬菜基地之一,目前,在河西地区主要栽培的是结球生菜,近年来在河西地区种植面积不断加大,种子的需求量也与日俱增。结球生菜是喜欢高温的绿叶类蔬菜,在 Lettuce, also known as leaf lettuce, is an annual or perennial herb of Asteraceae. There are two main categories of lettuce and knot lettuce, in which the knot lettuce is a kind of special vegetable. Located in the middle of Hexi area, Zhangye City is one of the largest vegetable bases in Gansu Province. At present, the main cultivated lettuce is in Hexi area. In recent years, the area planted in Hexi area has been constantly increasing, and the demand for seeds has also been increasing. Knotted lettuce is like green leafy vegetables at high temperatures