近年来我区小麦生产由于种植品种多 ,又没有建设配套的良种繁育基地和相应的小麦供种体系 ,使农民用不上纯度高、品质优、合格的小麦种子。因而农民自行留种 ,自己串换种子现象普遍存在 ,造成大田品种混杂退化严重。推广一个新品种不到３年就变成了一个混合体 ,失去了一个优良 In recent years, wheat production in our region due to planting more varieties, there is no construction of supporting breeding base and the corresponding wheat seed supply system, so farmers do not use the high purity, good quality, qualified wheat seeds. As a result, peasants kept their own species and their own seed exchange for seeds was widespread. As a result, the mixed and deteriorated varieties of the fields were seriously degenerated. Popularizing a new breed becomes a hybrid in less than three years, losing a good one