树木在长期系统发育的过程中,受自然环境和人工栽培的影响,产生了极大的变异。因此,在同一种树木的种子播种所产生的后代里,常常有不同类型的苗木。1973年4月中旬,我们在调查苦楝苗木越冬情况时发现:有些苗木在开始放叶时幼芽呈现明显的紫黑色;另一些苗木的芽为黄绿色;还有一些苗木芽的颜色介于二者之间——虽呈紫黑色,但较浅淡。 Trees in the long-term phylogenetic process, under the influence of the natural environment and artificial cultivation, produced a great variation. Therefore, different types of seedlings are often found in the offspring produced by sowing seeds of the same species. In mid-April 1973, when we surveyed the overwintering situation of Azadirachta indica seedlings, we found that: some of the seedlings showed obvious purplish black when they started to put leaves; others had yellow-green buds; others had a color of between 2 Between - although was purple, but more pale.