A naturally-occurring resistance gene against the spruce bud worm: genomic characterization, and applications in Canadian tree breeding and pest management

云杉芽虫（SBW）是北美东部最具破坏性的落叶森林害虫之一。树木死亡和生长减少在上一次大爆发（1973-1987年）期间造成3.8亿立方米木材损失。自2007年以来，加拿大东部严重的SBW落叶面积呈指数增长。加拿大西部还有另外三种SBW受到关注。种植具有持久的SBW抗性的云杉幼苗是减少森林供应损失和更新林地的理想策略。然而，实现这一目标的关键知识和诀窍一直缺乏。我们最近在白云杉（Picea glauca）中发现了对SBW的自然抗性。这为森林病虫害管理和自然资源保护这一重要领域的重大创新打开了大门。两种酚类化合物（piceol和pungenol）的积累似乎可以解释SBW抗性的这种表型变异。单个-葡萄糖苷酶候选基因的表达与这些性状密切相关。我们建议利用这些化合物的积累和β -葡萄糖苷酶基因的表达作为开发遗传抗性树木的抗性生物标志物，并作为评估自然和管理森林脆弱性的方法。加拿大东部和西部的主要云杉品种将有机会培育出抗SBW的树木。真冷杉和道格拉斯冷杉也将被研究。工业和公共部门支持组织将为研究和将研究成果转化为实际应用作出贡献，为加拿大的环境和经济发展带来利益。此外，我们还将探讨昆虫对SBW抗性的分子生化机制，并研究酚类化合物对昆虫发育和选择进化的影响。我们的团队结合了国际公认和互补的专业知识，以支持这一跨学科和创新的研究。预期的结果将产生新的工具和技术，以确定更高价值的种植资源，并最大限度地利用我们的林地供应纤维、木材和能源资源。

The spruce budworm (SBW) Choristoneura fumiferana (Clem.) is among the most destructive defoliating forest pests of eastern North America. Tree deaths and reduced growth caused losses of 0.38 billion cubic meters of wood during the last major SBW outbreak (1973-1987). Areas of heavy SBW defoliation have increased exponentially in eastern Canada since 2007. Three other species of SBW are of concern in western Canada. Planting spruce seedlings that have durable SBW resistance is a desirable strategy to reduce losses of forest supply and renew our timberlands. However, critical knowledge and know-how for reaching this goal have been lacking. We recently discovered naturally-occurring resistance to the SBW in white spruce (Picea glauca). This opens the doors to major innovations in this important area of forest pest management and natural resource protection. The accumulation of two phenolic compounds (piceol and pungenol) appears to explain this phenotypic variation in SBW resistance. Expression of a single beta-glucosidase candidate gene is strongly correlated with these traits. We propose to use accumulation of these compounds and expression of the beta-glucosidase gene as resistance biomarkers for developing genetically resistant trees and an approach for evaluating the vulnerability of natural and managed forests. Opportunities for breeding SBW resistant trees will be developed in major spruce species from eastern and western Canada. True fir and Douglas-fir will also be studied. Industry and public sector supporting organizations will contribute to the research and the translation of research results into practical applications, for the development of environmental and economic benefit to Canada. We will also investigate the molecular and biochemical mechanisms related to SBW resistance and study the impacts of the phenolic compounds on insect development and selective evolution. Our team combines internationally recognized and complementary expertise to support this interdisciplinary and innovative research. Anticipated outcomes will result in new tools and techniques for identifying higher value planting stocks and for maximizing the use of our forest land for supply of fibre, wood and energy resources.