成年银杏雌雄株非花果期形态学差异性比较分析

为探寻成年雌雄银杏形态学差异,调查了成年银杏雌雄株花芽发育形态,短、长枝叶片形态指标,春、秋季叶片叶绿素质量比的变化以及气孔密度的表观特征.结果表明:银杏雌花芽呈尖锐圆锥形,雄花芽呈饱满半球形;同性别银杏单株间形态特征差异不显著,具有相对稳定性;雌株短枝、长枝叶片叶长、叶宽、叶基夹角、叶面积和叶形指数都分别显著小于雄株对应枝条上相应叶片形态特征,而叶柄显著大于雄株叶柄;春季,雌株短枝、长枝叶片叶绿素质量比分别高于雄株17.48%,31.03%;秋季,雌株短枝、长枝叶片叶绿素质量比分别低于雄株6.25%,21.82%;春季雌株较雄株浓绿,秋季雄株较雌株晚黄;雌株短枝、长枝叶片的气孔密度都分别显著高于雄株相应的短枝、长枝上的叶片气孔密度.研究结果证明:银杏叶片表观特征与性别分化关联密切;非花果期鉴定成年银杏性别,可依据花芽形态特征、银杏叶片叶色、叶绿素质量比、气孔密度的差异来初步鉴别.

Analysis of Morphological Differences of the Leaves of Adult Ginkgo Trees in the Non-Flowering and Non-Fruiting Period

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.