Seed germination at different stratification temperatures and development of Phytelephas macrocarpa Ruiz & Pavón seedlings

Abstract: Phytelephas macrocarpa (ivory palm) is an Amazonian palm vulnerable to exploitation pressure, as its seeds are widely used in regional handicrafts. The aims of this study were to evaluate the effectiveness of different stratification temperatures in overcoming seed dormancy and to analyze the seedling development stages of this species. In germination under stratification, the seeds were placed in plastic bags containing moistened vermiculite, and maintained at the constant temperatures of 25, 30, 35 and 40 °C, and an alternating temperature from 26 to 40 °C. In the study about the development of seedlings, seeds were sown in vermiculite under plastic cover (growing house), and the evolution of the seedling was evaluated, from the formation of germinative button to the complete blade expansion of the first eophyll. Stratification at alternating temperatures (26 to 40 °C) helped overcoming seed dormancy. Stratification at 25 °C kept the seed viability for nine months. Germination, characterized by the formation of the germinative button took an average of 114 ± 24 days, and the seedling development until the first extended eophyll lasted 244 ± 57 days.

摘要：大果直叶椰（Phytelephas macrocarpa，象牙棕榈）是亚马逊流域的棕榈科植物，其种子因广泛应用于地区手工艺品制作而面临过度开发的生存压力。本研究旨在评估不同层积温度对打破该物种种子休眠的效果，并分析其幼苗发育阶段。在层积发芽实验中，将种子置于装有湿润蛭石的塑料袋内，分别置于25℃、30℃、35℃、40℃的恒温环境以及26~40℃的变温环境中培养。在幼苗发育研究中，将种子播种于覆有塑料膜的蛭石基质中（育苗室），并对幼苗从萌发钮形成至第一片初生叶完全展开的整个发育过程进行观测评估。研究结果表明，26~40℃的变温层积处理可有效打破种子休眠；25℃的恒温层积处理可将种子活力维持9个月。以萌发钮形成为标志的萌发过程平均耗时114±24天，从萌发完成至第一片初生叶完全展开的幼苗发育阶段平均耗时244±57天。