荚蒾属植物花期物候及生长对引种地年际气候波动的响应

专属引种植物的物候及生长研究能够掌握特定物候相在专属水平上的阈值,并为评估引种专属的适应潜力提供参考。通过对中国科学院植物研究所北京植物园内引种多年的9种荚蒾（Viburnum）的花期及2种荚蒾的生长动态进行观测,分析讨论了花期对冬春两季异常低温的响应及营养与生殖生长的关联机制。结果表明：2009–2010年冬春异常低温后,荚蒾始花期的整体延迟是由春季环境热量供应不及时所致,种间延迟程度的差异则与原产地的气候有紧密联系：分布于寒温带地区的欧洲绣球（V.opulus）和修枝荚蒾（V.burejaeticum）延迟天数最少（分别为10和12天）,分布于我国亚热带的琼花（V.macrocephalum）和桦叶荚蒾（V.betulifolium）延迟天数最多（分别为21和26天）。荚蒾花前有效积温介于39–368°C之间。经历异常低温后,花前有效积温呈上升和下降两种格局,与物种冷量和热量的内在需求有关。荚蒾属植物的生殖与营养生长呈现两种关联方式,早花种类开花座果伴随着营养生长的竞争,晚花种类花后即出现营养生长的支持,对果实发育的保障性较强。

The Response of Flowering Phenology and Growth of Viburnum to Interannual Weather Fluctuation in an Introduction habitat

The phenology and growth research of a naturalized genus may offer information on phenophase threshold, thus providing references for evaluating adaptation potential. We observed the flowering season of 9 Viburnum species and the growth dynamics of 2 Viburnum species in the Beijing Botanical Garden. We analyzed and discussed the response of flowering season in acclimatizing to a winter-spring abnormally low temperature in 10 years and the mechanism linking vegetative to reproductive growth. The abnormally low winter-spring temperature in 2009-2010 delayed flowering in all Viburnum species. Delayed anthesis was attributed to the delayed heat in spring. The delay was closely related to the environmental condition of distribution sites in some species： V. opulus and V. burejaeticum, distributed in frigid temperate zones, showed the shortest delay times （10, 12 days, respectively）, whereas V. macrocephalum and V. betulifo/ium, in subtropical zones, showed the longest delay times （21, 26 days, respectively）. Pre-anthesis effective ac- cumulated temperature in Viburnum was between 39~C and 368~C. The pre-anthesis effective accumulated temperature was increased or decreased among species after the abnormally low winter-spring temperature, which may be attributed to the different chilling-heat requirement of anthesis among the species. The linkage of vegetative and reproductive growth showed 2 forms： reproductive growth in early-anthesis species was strongly competed with vegetative growth, whereas in late-anthesis species showed effective supply, because vegetative growth in late anthesis can supply assimilates to reproductive growth immediately after the completion of flowering.