山玉兰中3～7个胚珠的发现

Discovery of 3～7 Ovules in One Carpel of Magnolia delavayi

通过对山玉兰（Ｍａｇｎｏｌｉａｄｅｌａｖａｙｉ）两个居群各１０个果的解剖，发现其心皮中的胚珠数目是变化的，１个果上的心皮中分别具有２～７枚胚珠，１心皮具有３、４、５、６和７枚胚珠的数目在木兰属中首次发现。在木兰科中，心皮中所具有的胚珠数目是分属的重要依据之一，木兰属和木莲属是根据心皮中胚珠的数目来划分的，前者具２胚珠，而后者具４～１６胚珠。木兰属中具３、４、５。

This paper deals with the number of ovules in Magnolia delavayi .The fruits from two population of M delavayi were checked anatomically.The result shows that the number of ovules is variable.2～7 ovules were observed in different carpels from the same fruit of M delavayi .3,4,5,6 and 7 ovules in one carpel were discovered in the genus Magnolia for the first time.The number of ovules in a carpel is the most important taxonomic characteristic that distinguishes two genera, Magnolia and Manglietia .There are two ovules in one carpel of the genus Magnolia while 4～16 in Manglietia .The discovery of 3～7 ovules in one carpel of Magnolia delavayi implies that Magnolia and Manglietia may be the same genus.This result supports Baillon′s proposal that the genus Manglietia should be incorporated into the genus Magnolia .