Genotypic variation in drought response of silver birch (Betula pendula Roth):: leaf and root morphology and carbon partitioning
Genotypic variation in drought response of silver birch (Betula pendula Roth):: leaf and root morphology and carbon partitioning
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DOI：
10.1007/s00468-005-0011-9
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发表时间：
2006-01-01
影响因子：
2.3
通讯作者：
Leuschner, C
中科院分区：
文献类型：
--
作者：
Aspelmeier, S;Leuschner, C
研究了垂枝桦4个基因型的叶片和根系形态特征、叶片物候和碳在地上部和根系间的分配对干旱胁迫的响应。盆栽一年生无性系植物的四个基因型，从低到高的年降雨量（550-1270毫米年（-1））的地区进行了12-14周的干旱期在随后的两年。4种基因型的对照植株在单株总叶面积（LA）和比叶面积（SLA）方面差异显著，而在总细根表面积（RA）、根比面积（SRA）和细根：叶质量比（FR：LM）方面差异不显著。最高的LA和SLA被发现在克隆起源于最干燥的环境。在补充生理调查中，发现该克隆具有最高的用水量，这被解释为在耗水量方面的竞争优势。干旱导致所有基因型的SLA增加，LA减少。叶面积减少更明显的基因型从高比那些从低降雨量的起源。总根叶表面积的比例保持或多或少的恒定干旱后，尽管增加FR：LM。这可以通过干旱处理的植物中非常小的细根（直径< 0.2 mm）的丰度降低导致SRA降低来解释。由于最细根质量的减少而导致的总根表面积的损失通过每株植物总根干质量的相对增加来补偿。比较第一和第二干旱期的结果表明，干旱的时间，根系大小，和假定的根限制植物干旱反应的显着影响。我们的结论是，叶和根的形态，叶和根的总表面，以及在桦树干旱的形态反应在很大程度上受遗传控制。
This study investigates the drought response of four genotypes of Betula pendula with a focus on leaf and root morphological traits, leaf phenology and carbon partitioning between shoot and root. Potted one-year-old clonal plants of four genotypes from regions with low to high annual rainfall (550-1270 mm year(-1)) were subjected to drought periods of 12-14 weeks in two subsequent years. Well-watered control plants of the four genotypes differed significantly with respect to total leaf area per plant (LA) and specific leaf area (SLA), whereas differences in total fine root surface area (RA), root specific area (SRA), and the fine root:leaf mass ratio (FR:LM) were not significant. Highest LA and SLA were found in the clone originating from the driest environment. In complementary physiological investigations this clone was found to have the highest water use as well which was interpreted as competitive superiority in terms of water consumption. Drought resulted in an increase in SLA in all genotypes, and a decrease in LA. Leaf area reduction was more pronounced in the genotypes from high than in those from low rainfall origin. The ratio of total root to leaf surfaces remained more or less constant after drought application despite an increase in FR:LM. This is explained by a decrease in SRA resulting from a reduced abundance of very small fine rootlets (diameter < 0.2 mm) in the drought-treated plants. The loss in total root surface area due to a reduction in finest root mass was compensated for by a relative increase in total root dry mass per plant. Comparison of results from the first and second drought period indicated a marked influence of timing of drought, root system size, and putative root limitation on plant drought response. We conclude that leaf and root morphology, the total leaf and root surfaces, and the morphological response to drought in birch are to a large extent under genetic control.