性状的变异有连续的变异和不连续的变异.如:树冠的浓密与稀疏,树枝的粗、细,叶面白粉或毛的有无,种壳的斑点或毛的有无等,这些成对的性状,不易受环境条件的影响发生变异,彼此差别明显,不易混淆,一般没有中间类型,即使由于显性不完全,出现中间类型,仍然可以把它们区分归类,这种具有明显界限的 Traits of variation with continuous variation and discontinuous variation, such as: crown dense and sparse, the branches of crude, fine, foliar white flour or hair, the shell of the spots or the presence of hair, etc. These pairs Are not easily affected by environmental conditions, they are different from each other and are not easy to be confused. Generally, there is no intermediate type, and even though the middle type appears due to the apparent imperfection, it is still possible to classify them differently. This obvious boundary