论文部分内容阅读
次级花粉呈现是植物提高花粉输出和接受的效率与准确性以及促进异交的一种繁殖策略。新疆党参(Codonopsis clematidea)具有典型的次级花粉呈现特性。本文采用野外观测、授粉实验与室内显微观测等方法,对该物种的花部综合征及其次级花粉呈现过程进行了详细观测,并对这些特征的适应意义进行了探讨。结果表明:新疆党参钟状下垂的蓝色花冠及黑黄色蜜腺,不仅避免了雨水冲刷雌雄蕊、稀释花蜜以及风移出花粉等不利影响,还增加了对传粉者的吸引,延长了花粉活力及柱头可授性持续时间。次级花粉呈现属于亚顶端花柱呈现者,呈现机制为沉积机制。该特性限制了单个传粉者带走的花粉量,延长了花粉呈现时间,使更多传粉者参与传粉过程,增加了雄性适合度。其雄性先熟及雌雄蕊空间位置变化,避免了雌雄功能干扰,为传粉者取食花蜜、输出花粉以及柱头接受异源花粉提供了通道和机会。其泛化传粉系统的主要传粉昆虫为林野熊蜂(Bombus silvarum)、草地熊蜂(B.paradoxus)和树长黄胡蜂(Dolichovespula sylvestris),其较长的单花花期(6d左右),昆虫访花高峰期与花粉活力最高时期及柱头最佳授粉期相吻合,以及较大的泌蜜量、较高的花蜜糖浓度和较长的泌蜜时间等特征,可提高传粉者的访花频率,增加成功传粉的机会和传粉效率。在气候多变的天山山区,该物种特殊的花部综合征和次级花粉呈现机制对提高其传粉效率并促进异交繁殖成功具有重要意义。
Secondary pollen presentation is a plant strategy to increase the efficiency and accuracy of pollen output and acceptance and to promote outcrossing. Codonopsis clematidea has typical secondary pollen characteristics. In this paper, field observation, pollination experiments and indoor microscopic observation methods were used to observe the flowering syndrome and secondary pollen appearance of this species in detail, and the significance of adaptation of these characteristics were discussed. The results showed that the blue-crowned corolla and black-yellow nectaries of bell-shaped cactus in Xinjiang not only avoided the unfavorable effects of rain and stamen washing, diluted nectar and the wind moved out of pollen, but also increased the attraction to pollinators and prolonged the pollen viability Stigma receptivity duration. Secondary pollen presents subtropical style presented, the mechanism for the deposition mechanism. This feature limits the amount of pollen taken away by a single pollinator, prolongs the pollen appearance time, allows more pollinators to participate in the pollination process, and increases the male fitness. The males are familiar with the changes of the spatial position of the female and the stamen, avoiding the interference of male and female, providing access and opportunities for pollinators to feed on nectar, output pollen and stigma to heterosexual pollen. The main pollinators of the generalized pollination system were Bombus silvarum, B. pararadoxus and Dolichovespula sylvestris. The longer pollen flowering period (about 6 days) The period coincided with the peak period of pollen viability and the optimal pollination period of stigma, as well as the characteristics of larger excretion of nectar, higher concentration of nectar and longer nectar time, which could increase the pollination frequency and increase the success of pollinators Pollination opportunities and pollination efficiency. In the ever-changing Tianshan Mountains, the special flowering syndrome and the secondary pollen presentation mechanism of this species are of great significance to improve the pollination efficiency and promote the success of outcrossing.