EFFECT OF LIGHT, TEMPERATURE AND SCARIFICATION ON THE GERMINATIVE CAPACITY AND INITIAL GROWTH OF Myroxylon balsamum (L.) HARMS

ABSTRACT Myroxylon balsamum is a valuable tropical tree; besides the good quality of its timber it also provides valuable nontimber forest products: balsam and resin. High deforestation rates in the area of distribution and the unregulated extraction of its resin and wood have led M. balsamum to be endangered or threatened. Its regeneration through seeds has been poorly studied, and there are no reports of germination and plasticity under controlled conditions. We evaluated the effect of scarification (longitudinal cut of the fruit and embryo fully exposed) and environmental factors (different levels of light intensities and changing temperatures) on seed germination and the development of seedlings. From the aforementioned, M. balsamum seeds are orthodox and show physical dormancy. In view of these characteristics, M. balsamum can be managed efficiently to initiate conservation programs and restoration in degraded land.

摘要
香脂豆（Myroxylon balsamum）是一种极具经济价值的热带树种：其不仅拥有品质上乘的木材，还可产出香脂与树脂等高价值非木材林产品。该树种分布区域内的森林砍伐率居高不下，加之树脂与木材的无序采伐，已导致香脂豆（M. balsamum）沦为濒危或受威胁物种。目前针对其种子繁殖的研究仍较为匮乏，且尚无受控条件下种子萌发与可塑性的相关报道。本研究评估了划破种皮处理（即对果实进行纵切，使胚完全暴露）与环境因子（不同光照强度梯度与变温条件）对其种子萌发及幼苗生长的影响。综上可知，香脂豆（M. balsamum）的种子为正常型种子（orthodox seed），且存在物理休眠现象。基于上述特性，可对香脂豆开展高效管护，以启动退化土地的保护计划与生态修复工作。