Ferrandis Pablo, Bonilla Marta, Osorio Licet del Carmen
Grupo de Biología de la Conservación de Plantas, Instituto Botánico de la Universidad de Castilla La Mancha, Jardín Botánico de Castilla-La Mancha, Campus Universitario s/n, Albacete 02071, España.
Rev Biol Trop. 2011 Sep;59(3):1061-9.
Podocarpus angustifolius is an endangered recalcitrant-seeded small tree, endemic to mountain rain forests in the central and Pinar del Río regions in Cuba. In this study, the germination patterns of P. angustifolius seeds were evaluated and the nature of the soil seed bank was determined. Using a weighted two-factor design, we analyzed the combined germination response to seed source (i.e. freshly matured seeds directly collected from trees versus seeds extracted from soil samples) and pretreatment (i.e. seed water-immersion for 48h at room temperature). Germination was delayed for four weeks (= 30 days) in all cases, regardless of both factors analyzed. Moreover, nine additional days were necessary to achieve high germination values (in the case of fresh, pretreated seeds). These results overall may indicate the existence of a non-deep simple morphophysiological dormancy in P. angustifolius seeds. The water-immersion significantly enhanced seed germination, probably as a result of the hydration of recalcitrant seeds. Although germination of seeds extracted from soil samples was low, probably due to aging and pathogen effects throughout the time of burial, the study revealed the existence of a persistent soil seed bank (at least short-termed) of approximately 42 viable seeds per m2 in the upper 10cm of soil. Such a record is noteworthy since references to persistent soil seed banks in recalcitrant-seeded species are scarce in the literature. The population consequences derived from the formation of persistent soil seed banks in this endangered species are discussed.
狭叶罗汉松是一种濒危的顽拗型种子小树，特产于古巴中部和比那尔德里奥省的山地雨林。在本研究中，对狭叶罗汉松种子的萌发模式进行了评估，并确定了土壤种子库的性质。采用加权双因素设计，我们分析了种子来源（即直接从树上采集的新鲜成熟种子与从土壤样本中提取的种子）和预处理（即在室温下将种子水浸48小时）对萌发的综合响应。无论分析的两个因素如何，在所有情况下萌发都延迟了四周（=30天）。此外，还需要额外九天才能达到高萌发率（对于新鲜、预处理的种子而言）。总体而言，这些结果可能表明狭叶罗汉松种子存在非深度简单形态生理休眠。水浸显著提高了种子萌发率，这可能是顽拗型种子水合作用的结果。尽管从土壤样本中提取的种子萌发率较低，这可能是由于在埋藏期间老化和病原体的影响，但该研究揭示了在土壤上层10厘米处存在一个持续的土壤种子库（至少短期），每平方米约有42粒有活力的种子。鉴于文献中关于顽拗型种子物种持续土壤种子库的记载很少，这样的记录值得注意。本文讨论了这种濒危物种中持续土壤种子库形成所产生的种群后果。
