许多冬性一年生植物和二年生植物,在种子萌动后或个体生育前期的一段时间内,对温度有一定的要求。例如冬小麦,苗期的正低温是以后穗分化不可缺少的条件。人们把低温促进花芽形成的过程叫春化现象,而把对作物幼苗进行人工低温处理以促进开花的技术叫做春化处理。我国劳动人民很早就对作物开花、结实和温度变化的关系有所认识,将萌动的冬小麦种子放在土罐中,埋在露地或吊在井里进行“冻麦催花”,防止冬小麦春播不穗。研究表明,我国不同生态型的小麦品种,以北纬33度为界,界线以南的品种一般要求0—12℃,12—26天通过春化;界北的品种一般要求0—7℃,36—51 Many winter annuals and biennials have certain temperature requirements during the period after the seed germinates or during the early part of the child’s life. For example, winter wheat, seedling is the cold is the indispensable conditions for the subsequent spike differentiation. The process of low temperature to promote flower bud formation is called vernalization. The technique of artificial low-temperature treatment of crop seedlings to promote flowering is called vernalization. Earlier, working people in our country knew something about the flowering and fruiting of crops and the relationship between temperature and temperature. Germinated winter wheat seeds were placed in soil pots and buried in open fields or hanging in wells for “cold wheat inoculation” to prevent spring wheat sowing Not spike. Studies have shown that different ecotypes of wheat varieties in our country at 33 degrees north latitude, the line south of the general requirements of 0-12 ℃, 12-26 days through the vernalization; border north varieties generally require 0-7 ℃, 36 -51