Abstract Arid environments demand specific adaptations from plants in vegetative and reproductive systems. Self–compatibility, high pollen production and few well developed fruits are adapted to increase sexual reproductive success. Dorema aucheri is an arid–adapted, perennial monocarpic species endemic to southern Iran. It has a unique inflorescence structure. In this study, significance of inflorescence architecture for reproductive success was investigated in a wild population. The huge yellow inflorescences were frequently visited by manifold insects. The species is andromonoecious and spatially subdivided in a distal part with perfect flowers and a proximal part with male flowers. Flowers are protandrous and synchrononized in a duodichogamous manner which starts with the male, then female phase of the perfect flowers, followed by the male phase of the remaining flowers (7–10 days). Bagging assays confirmed that the plant is self–fertile. Sexual phases partly overlap allowing geitonogamy at some days and demanding obligate outcrossing at other days. The mixed breeding system and high degree of andromonoecy (77 ± 31%) coupled with an immense surplus of pollen grains (P/O =261,991:1), the long male flowering stage, attraction of flying pollinators by massive flowering and sexual asynchrony between neighboring plants are interpreted as adaptations to the arid environment increasing the rate of outcrossing.

中文翻译：

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Dorema aucheri (Apiaceae) 独特的花序结构：对干旱环境的适应

摘要 干旱环境要求植物在营养和生殖系统中进行特定的适应。自交亲和性、高花粉产量和很少发育良好的果实都适合增加有性繁殖的成功率。Dorema aucheri 是伊朗南部特有的一种适应干旱的多年生单果树种。它具有独特的花序结构。在这项研究中，在野生种群中研究了花序结构对繁殖成功的重要性。巨大的黄色花序经常被各种昆虫访问。该物种是雄性雌雄同株，在空间上细分为具有完美花朵的远端部分和具有雄花的近端部分。花朵以双双配方式同步，从雄性开始，然后是完美花朵的雌性阶段，然后是剩余花的雄性阶段（7-10 天）。装袋试验证实该植物是自育的。性阶段部分重叠，允许在某些日子进行异性婚配，而在其他日子要求专性异交。混合繁殖系统和高度的雄性花粉（77±31%），加上大量的花粉粒（P/O=261,991:1），雄性花期长，大量开花吸引飞行传粉者，之间的性不同步。邻近的植物被解释为对干旱环境的适应，增加了异交率。