Drought-Conditioning of Quaking Aspen (Populus tremuloides Michx.) Seedlings During Nursery Production Modifies Seedling Anatomy and Physiology
Drought-Conditioning of Quaking Aspen (Populus tremuloides Michx.) Seedlings During Nursery Production Modifies Seedling Anatomy and Physiology
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DOI：
10.3389/fpls.2020.557894
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发表时间：
2020-09-04
影响因子：
5.6
通讯作者：
Pinto, Jeremiah R.
中科院分区：
文献类型：
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作者：
Sloan, Joshua L.;Burney, Owen T.;Pinto, Jeremiah R.
在美国西部，颤杨(Pillius tremuloidesMichx.)在低到中等严重火灾等干扰后，主要由根部吸管再生。种植由种子培育的杨树幼苗可以提供一种机制，在严重干扰的地点提高恢复成功率和遗传多样性。然而，很少有研究从外植和苗圃生产的角度来考察容器培养的杨树幼苗用于恢复目的。因此，这项新颖的研究的目的是研究在苗圃生产过程中，三种种子来源的灌溉水平的变化如何影响严酷、干燥的露地苗木的表现属性。灌溉处理基于三种灌溉水平，按重量计算：高=容器容量的90%，中=80%，低=70%。这三个种子来源代表了整个白杨山脉(新墨西哥州、犹他州和艾伯塔省)的纬度梯度。碳同位素分析表明，与高灌溉水平下的苗木相比，低、中灌溉水平下的灌溉处理有效地造成了更高的水分胁迫水平。与高灌水水平相比，低灌水水平的幼苗能够诱导出更高的高度、更高的光合速率、更高的水力活性木质部百分比和更快的木质部流动速度。灌溉处理与种子来源之间几乎所有反应变量之间缺乏交互作用，这表明苗圃条件通过灌溉限制对一系列杨树种子来源可能是有效的。
In the western US, quaking aspen (Populus tremuloidesMichx.) regenerates primarily by root suckers after disturbances such as low to moderate severity fires. Planting aspen seedlings grown from seed may provide a mechanism to improve restoration success and genetic diversity on severely disturbed sites. However, few studies have examined the use of container-grown aspen seedlings for restoration purposes from both the outplanting and nursery production perspective. Thus, the purpose of this novel study was to examine how alterations in irrigation levels during nursery production across three seed sources would impact seedling performance attributes on harsh, dry outplanting sites. Irrigation treatments were based on three irrigation levels, determined gravimetrically: High = 90%, Medium = 80%, and Low = 70% of container capacity. The three seed sources represented a latitudinal gradient across the aspen range (New Mexico, Utah, and Alberta). Carbon isotope analysis indicated irrigation treatments were effective in creating higher levels of water stress for both the Low and Medium irrigation levels compared to seedlings under the High irrigation level. Seedlings subject to the Low irrigation level were found to induce greater height, higher photosynthetic rates, larger percentages of hydraulically active xylem, and faster xylem flow velocities compared to the High irrigation level. The lack of an interaction between irrigation treatments and seed source for nearly all response variables suggests that nursery conditioningviairrigation limitations may be effective for a range of aspen seed sources.