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

世界各地都在使用速生树种种植园来满足对木材纤维日益增长的需求。这一策略在加拿大也得到了发展，因为森林工业正在寻找靠近磨坊的边缘农田，建立杂交杨树种植园作为木材供应的新来源。来自不同杨树品种的亲本杂交是最多产的树木之一，在商业种植园中被广泛种植。由于其优越的生长特性，杂交杨树是纸浆、实木产品和加拿大林业能源的宝贵新来源。树木必须能够应对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。预计该地区干旱的频率和严重程度都会增加。有必要详细了解商业种植的杨树基因型的水分关系。由于杨树对供水敏感，许多工作都集中在提高其水分利用效率和耐旱性，同时在各种干旱易发地点保持足够的生产力，并在没有灌溉的情况下有效利用现有的土地基础。虽然杂交杨树作为一个群体具有很高的产量，但单克隆在生长和抗逆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显示出可接受的生长性能。“可变”克隆在一些网站上表现出可接受的增长，而在其他网站上表现不佳。我们将使用广泛的方法来研究稳定与可变无性系的水分关系和选定的木材解剖性状。该研究利用各种分子和基因组工具来研究转录组重组如何支持对不同环境条件的生理和发育调整。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奠定坚实的科学基础，是对林业经济成功的一项战略性投资。

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.