Rowell Douglas M, Ades Peter K, Tausz Michael, Arndt Stefan K, Adams Mark A
Department of Forest and Ecosystem Science, School of Land and Environment, University of Melbourne, Parkville VIC 3010, Australia.
Tree Physiol. 2009 Feb;29(2):191-8. doi: 10.1093/treephys/tpn015. Epub 2008 Dec 5.
We assessed the variation in delta(13)C signatures of Pinus radiata D. Don stemwood taken from three genetic trials in southern Australia. We sought to determine the potential of using delta(13)C signatures as selection criteria for drought tolerance. Increment cores were taken from P. radiata and were used to determine the basal area increment and the delta(13)C signature of extracted cellulose. Both growth increment and cellulose delta(13)C were affected by water availability. Growth increment and delta(13)C were negatively correlated suggesting that growth was water-limited. While there was significant genetic variation in growth, there was no significant genetic variation in cellulose delta(13)C of tree rings. This suggests that different genotypes of P. radiata display significant differences in growth and yet respond similarly to drought stress. The delta(13)C response to drought stress was more due to changes in stomatal conductance than to the variation in photosynthetic capacity, and this may explain the lack of genetic variation in delta(13)C. The lack of genetic variation in cellulose delta(13)C of tree rings precludes its use as a selection criterion for drought tolerance among P. radiata genotypes.
我们评估了从澳大利亚南部三个遗传试验中采集的辐射松（Pinus radiata D. Don）树干木材的δ(13)C特征变化。我们试图确定将δ(13)C特征用作耐旱性选择标准的潜力。从辐射松中采集了增量芯，用于确定断面积增量和提取纤维素的δ(13)C特征。生长增量和纤维素δ(13)C均受水分供应的影响。生长增量与δ(13)C呈负相关，表明生长受到水分限制。虽然生长存在显著的遗传变异，但年轮纤维素δ(13)C不存在显著的遗传变异。这表明辐射松的不同基因型在生长方面表现出显著差异，但对干旱胁迫的响应相似。δ(13)C对干旱胁迫的响应更多是由于气孔导度的变化，而非光合能力的变化，这可能解释了δ(13)C缺乏遗传变异的原因。年轮纤维素δ(13)C缺乏遗传变异，因此不能将其用作辐射松基因型耐旱性的选择标准。
