中国首次发现叶籽银杏子代无性系叶生胚珠表达——兼论其遗传稳定性

The first discovery of epiphyllous ovule from clone progeny of Ginkgo biloba var. epiphylla-in China with comments on its genetic stability

叶籽银杏是银杏这一孑遗物种的特殊种质,长期以来国内外学者对其实生和营养繁殖的后代叶生胚珠(叶生种实)的表达十分关注。该研究首次发现,从800年生的叶籽银杏母树上采集接穗嫁接12年后有6株幼树出现叶生胚珠并发育成正常叶生种实,这也是世界上仅有的6株幼龄叶籽银杏。叶籽银杏表达株率占9.68%,平均叶生种实率为0.074%。嫁接再生的叶籽银杏形态特征、种实特性、生长特性、变异特性与母树相同,表明叶籽银杏可视为一个品种,并具有稳定的遗传特性。

Ginkgo biloba var. epiphylla is a special germplasm in Ginkgo. For a long time, great attention is paid to whether the epiphyllous ovule （seed） can be expressed in the seedlings and clones of G. biloba var. epiphylla. We found the 6 young grafted trees of a 800 year old G. biloba var. epiphylla tree, which could produce epiphyllous ovule and the epiphyllous ovule can develop into epiphyllous seed. The expression of epiphyllous ovule （seed） in the grafted G. biloba var. epiphylla is reported for the first time in the world. The expression rate of the grafted ginkgo tree with epiphyllous ovule accounted for 9.68 %, and epiphyllous seeds rate accounted 0.074 %. Morphological characteristics, seed characteristics, growth characteristics, variation characteristics of grafted trees are identical to parent tree, which indicates that G. biloba var. epiphylla can be regarded as a culeivar and genetic stability.