其第二代发病率为6.2%，即F2健康后裔与患畜的比数接近15：1，作者用孟德尔自由组合规律和重叠作用原理解释了这一遗传现象。
The rate of healthy and diseased in F2 approached 15 to 1 . The authors explain this genetic phenomenon with the rule of free combination and multiple action principle of Mendel .
自由组合规律