Horizontal resistance, being variable in the wild state, can be domesticated. 水平抗性在野生狀態(tài)下是可變的,它可以馴化。
During breeding for vertical resistance, horizontal resistance tends to decline because of negative selection pressure. 當培育垂直抗性時(shí),由于負的選擇壓力,水平抗性趨于下降。