花粉和资源限制对荒漠地区梭梭种群传粉及种子萌发的影响

Pollination is crucial to a necessary stage of sexual reproduction in seed plants and is also the important life events in life cycle. The success of seed germination determines population reproduction and survival. In Haloxylon ammodendron, pollen and resource limitation have important impact on pollination and seed germination. However, some researches put pollen and resource limitation separately in related study, and studies of co-effect of pollen and resource limitation on the same population are rarely involved. In addition, the characteristics and mechanism of pollen and resources limitation are still unclear in pollination and seed germination. This research will be carried out by combining field investigation, control simulation experiment and laboratory analysis to study the co-effect of pollen and resource limitation and the sexual reproduction of H. ammodendron. We have studied the phenology, pollinators, pollination process, pollen and resources limitation, and seed germination of H. ammodendron, to clarify the effect of pollen and resources limitation on pollination traits and breeding system; defining pollen and resource limitation plays an important role in the sexual reproduction process of seed germination; exploring the relationship and mechanism among pollen and resource limitation, pollination and seed germination of H. ammodendron in desert ecosystem.

传粉过程既是种子植物有性生殖的必经阶段，也是其生活史中重要的生命活动。种子的成功萌发决定着种群的繁衍和生存。花粉和资源限制对梭梭的传粉和种子萌发产生重要影响。部分研究将资源和花粉限制单独看待，对同一种群是否同时受到资源和花粉限制的研究很少涉及，并且花粉和资源限制对梭梭种群传粉过程和种子萌发的影响机制尚不明确。本研究通过野外调查、控制实验和实验室分析相结合的方法，对荒漠优势植物梭梭的花粉和资源限制相互作用及其有性繁殖过程进行研究。我们对梭梭种群的开花物候、访花昆虫、传粉过程、花粉和资源限制、种子萌发进行研究，阐明花粉和资源限制对梭梭传粉特性和繁育系统的影响，确定花粉和资源限制在有性生殖过程中对梭梭种子萌发率的重要作用，探讨荒漠生态系统中梭梭种群的花粉和资源限制-传粉-种子萌发之间的相互关系及作用机理。

梭梭是中国西北荒漠地区的重要优势种。花粉和资源限制对梭梭的传粉和种子萌发产生重要影响。我们采用野外调查、控制实验、实验室分析的方法，对梭梭种群的花粉和资源限制、传粉过程进行研究。我们对梭梭种群的开花物候、访花昆虫、传粉过程和种子萌发进行观测。研究结果表明：花粉限制是影响结籽率的主要限制因子，昆虫访花频率的增强能够提高其结籽比率。在梭梭种群中，意大利蜂为主要的访花昆虫。我们发现植物花部特征的进化能够吸引访花昆虫，而昆虫访花频率的提高能够更好地利用植物花部资源。异花传粉是梭梭种群主要的传粉方式，虫媒传粉在异花传粉中起到重要作用。我们通过研究发现花粉和资源限制在有性生殖过程中对梭梭种子萌发率的重要作用。