Abstract:
Seed banks serve the purpose of maintaining germplasm for ex situ species preservation. Herbarium vouchers may be a viable source of unique and/or additional seeds for restoration as they can sometimes be from larger and more representative populations compared with seed banks. Rapid \'ōhi\'a death (ROD) has emerged as a serious threat against Hawaii\'s most iconic and foundational forest tree (Metrosideros spp.), and seed banking has been identified as an important strategy in preserving the genetic diversity of \'ōhi\'a. With respect to \'ōhi\'a we ask the following: (1) what is the long-term viability of \'ōhi\'a seeds stored in herbarium conditions, (2) how do herbarium curation practices affect seed viability, and (3) how long do seeds survive using conventional storage methods? We placed fresh \'ōhi\'a seeds in a herbarium dryer (57°C/5% relative humidity) for 5 days, freezer (-18°C/95% RH) for 2 weeks, and dryer then freezer, and compared against fresh control seeds. Seeds were harvested from a chronosequence of herbarium specimens, withdrawn from conventional storage conditions up to 3.75 and 6.5 years before experiments began, and germination assessed. There was no difference in the proportion germinated among treatments and control testing for herbarium entry (p = 0.56). Although no seeds from herbarium specimens germinated, freshly collected dried and frozen seeds germinated at a level equivalent to the control (p = 0.76). For seeds stored using conventional storage methods at 3.75 and 6.5 years, germination was equivalent to freshly harvested seeds. This suggests that seeds can survive the extreme climate conditions necessary to enter herbaria, but lose viability after storage at ambient conditions in 4 years or less. Although \'ōhi\'a seeds may be plentiful in herbaria, we recommend using seeds deposited into seed banks using conventional storage methods for orthodox seeds for postdisturbance restoration, and to combat ROD.
摘要:
种子库的目的是维护种质以进行异位物种保存。植物标本室券可能是用于恢复的独特和/或额外种子的可行来源,因为与种子库相比,它们有时可能来自更大,更具代表性的种群。快速死亡(ROD)已成为对夏威夷最具标志性和基础性的林树(Metrosiderosspp。),和种子库已被确定为保护\'ōhi\'a遗传多样性的重要策略。关于\'ōhi\'a,我们问以下问题:(1)在植物标本室条件下储存的种子的长期生存能力是什么?(2)植物标本室管理实践如何影响种子活力,和(3)使用常规储存方法种子存活多长时间?我们将新鲜的种子放在植物标本室干燥机(57°C/5%相对湿度)中5天,冷冻(-18°C/95%RH)2周,烘干机,然后是冰箱,并与新鲜对照种子进行比较。从植物标本室标本的时间序列中收获种子,在实验开始前3.75年和6.5年从常规储存条件中撤出,和发芽评估。在植物标本室进入的处理和对照测试之间发芽的比例没有差异(p=0.56)。虽然植物标本室标本的种子没有发芽,新鲜收集的干燥和冷冻种子以相当于对照的水平发芽(p=0.76)。对于使用常规储存方法在3.75和6.5年储存的种子,发芽相当于新鲜收获的种子。这表明种子可以在进入草本所必需的极端气候条件下生存,但在环境条件下储存后4年或更短的时间内失去活力。尽管草本中的种子可能很丰富,我们建议使用传统的储存方法将种子存入种子库,用于干扰后恢复。并与ROD作战。