Exploring variation in transcriptional profiles and hydraulic architecture in hybrid poplar clones

世界各地都在种植速生树种，以满足对木材纤维日益增长的需求。加拿大也在制定这一战略，因为林业将目光投向靠近工厂的边缘农田，以建立杂交白杨种植园作为木材供应的新来源。不同白杨品种的杂交种是最高产的树种之一，在商业人工林中广泛种植。由于其上级生长特性，杂交杨树是加拿大林业纸浆、实木产品和能源的宝贵新来源。树木必须能够科普包括干旱在内的环境压力。在加拿大西部，区域性干旱与树木死亡和白杨林生产力下降有关。预计干旱期的频率和严重程度将在该地区增加。有必要详细了解的水分关系的白杨基因型。由于杨树对水的供应很敏感，因此许多工作都集中在提高它们的水分利用效率和耐旱性，同时在各种干旱易发地区保持足够的生产力，并在不灌溉的情况下有效地利用现有的土地基础。尽管杂交杨树作为一个群体具有很高的生产力，但单个无性系在生长和胁迫耐受性方面表现出相当大的差异。“稳定”克隆在广泛的生长条件和地点上显示出可接受的生长性能。“可变”克隆在某些站点上表现出可接受的增长，而在其他站点上表现不佳。我们将使用广泛的方法来研究水分关系和选定的木材解剖性状的稳定与可变的克隆。这项研究利用各种分子和基因组工具来研究转录组的重构如何支持生理和发育对不同环境条件的调整。这项工作的结果将应用于树木育种和种植园管理计划。为不同地点的无性系选择建立强有力的科学基础是对林业经济成功的战略投资。

Plantations of fast-growing tree species are used around the world to meet the increasing demand for wood fiber. This strategyis also being developed in Canada, as the forest industrylooks to marginal farmlands, located close to mill sites, to establish hybrid poplar plantations as a new source of wood supply. Hybrids of parents from different poplar species are among the most productive trees and are widelyplanted in commercial plantations. Due to their superior growth characteristics, hybrid poplars are a valuable new source of pulp, solid-wood products, and energyfor the Canadian forest industry.Trees must be able to cope with environmental stress including drought. In western Canada, regional droughts have been linked with tree mortalityand reduced productivityin aspen forests. Drought periods are predicted toincrease in frequencyand severityin this region. There is a need for a detailed understanding of the water relations of commerciallygrown poplar genotypes. Since poplars tend to be sensitive to water supply, much work has focused on increasing their water use efficiencyand drought tolerance while retaining adequate productivityon various drought-prone sites and to utilize the existing land base efficientlywithout irrigation.Although hybrid poplars are highlyproductive as a group, individual clones show considerable differences in growth and stress tolerance. 'Stable' clones show acceptable growth performance over a wide range of growing conditions and sites. 'Variable' clones exhibit acceptable growth on some sites and poor performance on other sites. We will use a wide range of methods to studythe water relations and selected wood anatomical traits of stable versus variable clones. The proposed research takes advantage of various molecular and genomic tools tostudyhow physiological and developmental adjustments to different environmental conditions are underpinnedbyreconfiguration of the transcriptome. The findings from this work will be applied to tree breeding and plantation management programs. Developing a strong scientific basis for clone selection on different sites is a strategic investment into the economic success of the forest industry.