各种树木都有复杂的遗传性和变异性。树木良好的和不良的特性、特征主要由遗传决定。同一树种,在生长速度上,产品的产量和质量上,对病虫害和其他灾害的抗性上,都有不同程度的差别,有的个体(或群体)显著地表现了这种特性。由于遗传因素的不同和内部组织的改变,常在不同时期、不同地区出现和亲本不同的类型,形成新的变种或品种。树种的变异是客观存在的,变异的方式有共同的趋势。物种的变异是绝对 All kinds of trees have complex heredity and variability. The good and bad characteristics of trees are mainly determined by their genetics. The same tree, in terms of growth rate, product yield and quality, resistance to pests and diseases and other disasters, have varying degrees of difference, and some individuals (or groups) significantly demonstrated this feature. Due to different genetic factors and internal organizational changes, often in different periods, different regions and different types of parents, the formation of new varieties or varieties. Variation of tree species is an objective reality, and there are common trends in the ways of mutation. Species variation is absolute