To identify the gender of ginkgo (Ginkgo biloba L.) effectively in the non-flowering and non-fruiting period, investigations were carried out of the flower bud morphological characters, the leaf morphological indexes, the chlorophyll content and the leaf stomatal density of adult ginkgo trees. The female flower buds were found to be thin and cone-shaped, and the male ones were plump and hemispheric in shape. The morphological characters of the trees of the same gender were relatively stable, with no significant difference. The length, width, phyllopodium angle, leaf area and leaf shape index (L/W ratio) of the leaves on the short and long shoots of the female trees were strikingly smaller than those of the male trees, while the petiole length of the female trees was greater than that of the male trees. In spring, the chlorophyll content of the leaves on short and long shoots of the female trees was 17.48% and 31.03% higher than that of the male trees, respectively. In autumn, the chlorophyll content of the leaves on short and long shoots the female trees was 6.25% and 21.82% lower than that of the male trees, respectively. The leaf color of the female trees was greener than that of the male trees in spring, and the male trees turned yellow later than the female trees in autumn. The stomatal density on the leaves of the female trees was dramatically higher than that of the male trees. In conclusion, the apparent characteristics of ginkgo leaves are closely associated with the gender of the tree. The gender of an adult ginkgo tree can be identified preliminarily through observing the differences of the developmental morphology of its flower buds, leaf morphological indexes, leaf color, chlorophyll contents and leaf stomatal density in the non-flowering and non-fruiting period.
Ginkgo biloba Lgenderleaf morphology on long/ short shootschlorophyll contentstomatal density