Abstract: To explore the bulbil forming rule of Dracocephalum rupestre,the abilities of forming and rooting,process of bulbil were studied by cultivation and field investigation. The results showed that the provenances and plant individual had an effect on the formation of the bulbils. The phenomenon that cultivated plants could produce bulbils indicated the change of growth environment affected the formation of bulbils of Dracocephalum rupestre.The bulbils were borne on the leaf axil of rachis after flowering. The rosulate leaves of bulbil were borne on the woody bulb. The bulbils close to the surface of soil easily rooted,but the bulbils located on the top of rachis could not root and fell with the withered aboveground plant parts. The bulbil had the ability to root in morphogenesis and physiology. The bulbil rooting and growing into seedling depended on the position of bulbil borne on the floral axis and touched the soil. The generation of bulbils was caused by climate change,but the mechanism was not clear and need further exploration. This study firstly reported Dracocephalum rupestre could produce bulbil,and provided certain basis for exploring biological evolution of Dracocephalum rupestre,meanwhile,enriched the bulbil plant species.

Key words: Dracocephalum rupestre, Bulbil, Root, Provenances, Climate change

摘要： 为探究毛建草（Dracocephalum rupestre Hance）形成珠芽的规律，本试验通过栽培观察与野外调查对毛建草形成珠芽的能力、珠芽形成过程与生根能力进行了研究。结果显示：毛建草种源及植株个体影响珠芽的形成，引种栽培的毛建草能产生珠芽表明生长环境的改变对珠芽形成有明显影响；珠芽由花后的花茎叶腋间萌发的侧枝形成，珠芽叶片呈莲座状着生在球状木质化的基部；靠近地表的珠芽在生长期内能生根，花茎中上部的珠芽则不能生根，并随着地上部枯黄而干枯凋落；珠芽的木质化基部具有生根的形态及生理功能，能否落地生根形成新一代植株主要取决于其着生位置及能否与土壤接触；珠芽的形成是受气候环境变化引起的，但气候变化诱发珠芽形成的机制不清晰，还需进一步探索。本研究首次报道了毛建草产生珠芽的现象，丰富了珠芽植物的种类，将为探索毛建草生物进化提供一定的研究基础。

关键词: 毛建草, 珠芽, 生根, 种源地, 气候变化