ABSTRACT

Santalum yasi, a sandalwood native to Fiji and Tonga, is a tree crop of significant economic potential for these countries. Development of a plantation industry underpinned by a breeding program is a high priority for industry development. Gathering information on heartwood development, oil yield and oil composition is a critical step for the domestication and tree breeding of the species. Oil yield and composition were determined for 86 Santalum core samples using gas chromatography and combined gas chromatography/mass spectrometry. Most (67) cores were from the lower boles of individual trees of S. yasi, with smaller samples of S. album and S. album × S. yasi, both of which are also commonly grown in Fiji and Tonga, and S. austrocaledonicum was included for comparison. Although the ages of the trees were unknown, they are likely to have been between 10 and 20 years. Relationships among traits, including solvent-extracted oil yield, oil composition, lower bole diameters under and over bark, and heartwood diameter, were examined. Yield was highly variable (0.05–11.8%) and only weakly correlated with underbark diameter at 30 cm above ground. Oil yield and percent composition of santalol oil components were strongly positively correlated. For those trees with oil yields >1% w/w, the oil composition was generally favourable relative to the international standard for S. album oil, with large proportions of santalols, particularly β-santalol. The study confirms that both harvesting and selection for genetic improvement of S. yasi trees younger than 20 years old are likely to be suboptimal, with unreliable heartwood and oil development. Further study of heartwood and oil development, both within individual trees and among genotypes in common-garden trials with known genetics and controlled environments and hosts, is a high priority. The development of an international standard for S. yasi, supporting the growth of a niche market for the product, is also recommended.

摘要

Santalum yasi是一种原产于斐济和汤加的檀香木，对这些国家而言具有重要的经济潜力。以育种计划为基础的种植业发展是产业发展的重中之重。收集有关心材发育，油产量和油成分的信息是该物种驯化和树木育种的关键步骤。使用气相色谱法和组合气相色谱/质谱法测定了86个Santalum岩心样品的油收率和组成。大多数（67）核心来自亚述链球菌的单棵树的下膛，而较小的样本为S. album和S. album × S. yasi，两者在斐济和汤加也很常见，为了比较起见，也包括了奥氏链霉菌。尽管树木的年龄未知，但它们可能在10至20年之间。研究了性状之间的关系，包括溶剂提取的油的产量，油的成分，树皮上下的较低胆径和心材直径。产量变化很大（0.05–11.8％），并且与离地面30 cm处的树皮下直径仅弱相关。产油量和檀香酚油成分的百分含量呈强正相关。对于那些油收率> 1％w / w的树木，油成分相对于国际标准的S. Album油来说通常是有利的，其中大量的檀香酚，特别是β-檀香醇。这项研究证实，采伐和选择年龄小于20岁的矢车菊的遗传改良可能都不理想，心材和油的发育不可靠。在具有已知遗传学，可控环境和宿主的普通花园试验中，进一步研究心木和油的发育，无论是在单个树内还是在基因型之间，都是当务之急。一个国际标准的制定S.亚思，支持利基市场产品的发展，还建议。