角果藜的结实格局及地下散布单位的入土机制

通过对藜科植物角果藜的物候、地上地下结实格局及地下散布单位入土方式的观察,结果表明,1)角果藜子叶期持续时间长;开花结实早,且持续时间长,约占整个生活周期的4/5。2)地下散布单位仅2枚,位于主茎第1节处,地上散布单位多数,位于三歧聚伞状分枝的叶腋处;形成地下散布单位的花具有专一性。3)地下散布单位以主动性的动态“翻转”模式并借助外力因素的被动方式顺利入土。地上地下结果特性是角果藜适应荒漠生境的特殊对策。

Fruit-set patterns and burial mechanism for subterranean dispersal units of Ceratocarpus arenarius

Ceratocarpus arenarius is an annual desert plant in the Junggar Basin, Xinjiang. It produces two clearly different types of fruits in aboveground and subterranean on the same plant. The main aims of this study was to investigate the phenology, fruit-set patterns and burial mechanism of the subterranean dispersal units of this species. Life history of C. arenarius is eight month. It has long cotyledon period, there are about 30 days. Blossoming and fruiting soon, and it has a long reproductive period, which accounts for 4/5 of the whole lifecycle. The subterranean dispersal units originate from two female flowers in the binate axils of the first node of the main stem. At the last ten-days of April, the two female flowers are pollinated on the ground; after bracts entirely concrete, the two subterranean fruits develop into underground in the middle ten days of June. The flowers of the subterranean dispersal units of C. arenarius have specificity due to it include only two flowers which are on the first node of the main stem. However, a number of aerial dispersal units on the leaf axil which forms a spherical shape. The subterranean dispersal units bury by both combinative dynamic of the “reversing” mode and passive mode by means of soil and sand brought by wind and rain. This fruiting traits are the adaptative strategies of C. arenarius to the unpredictable desert.