背景:水力传导率的变化可能是由于木质部的解剖结构和功能的物种特异性差异而引起的,反映了一系列缓慢而快速的资源经济连续体的植物策略。云杉(云杉属。),一种分布广泛、适应性强的树种,对于防止土壤侵蚀和实现气候调节至关重要。然而,目前缺乏对云杉属茎的解剖特征及其潜在驱动因素的变异性的全面了解,尤其是在普通花园中。
结果:我们评估了天水一个普通花园中生长的17种云杉的19种茎经济特性和水力特性,甘肃省,中国。在物种之间观察到生长和解剖特征的种间差异。具体来说,木质部水力传导率(Ks)和水力直径与厚度跨度比(TSR)呈显着负相关,细胞壁比,和管胞密度,与纤维长度呈显著正相关,和径向管胞的大小。PCA显示,前两个轴占方差的64.40%,PC1反映了水力效率和机械支撑之间的权衡,而PC2代表了高栓塞阻力和强矿坑灵活性之间的权衡。回归分析和结构方程模型进一步证实了管胞大小对Ks的影响。而特征DWT,D_r,和TSR间接影响了Ks。所有性状均未显示出显着的系统发育关联。皮尔逊的相关分析表明,大多数性状与经度之间有很强的相关性,在最干旱的季度平均温度的显著影响下,年降水量,在最潮湿的季度降水,和干旱指数。
结论:我们的结果表明,木质部解剖特征在系统发育中表现出相当大的变异性,与云杉平行同胞辐射演化和全球多样性的模式一致。通过整合茎木质部的解剖结构以及环境因素的起源和进化关系,我们的发现为云杉属的生态适应提供了新的见解。
BACKGROUND: Variations in hydraulic conductivity may arise from species-specific differences in the anatomical structure and function of the xylem, reflecting a spectrum of plant strategies along a slow-fast resource economy continuum. Spruce (
Picea spp.), a widely distributed and highly adaptable tree species, is crucial in preventing soil erosion and enabling climate regulation. However, a comprehensive understanding of the variability in anatomical traits of stems and their underlying drivers in the
Picea genus is currently lacking especially in a common garden.
RESULTS: We assessed 19 stem economic properties and hydraulic characteristics of 17
Picea species grown in a common garden in Tianshui, Gansu Province, China. Significant interspecific differences in growth and anatomical characteristics were observed among the species. Specifically, xylem hydraulic conductivity (Ks) and hydraulic diameter exhibited a significant negative correlation with the thickness to span ratio (TSR), cell wall ratio, and tracheid density and a significant positive correlation with fiber length, and size of the radial tracheid. PCA revealed that the first two axes accounted for 64.40% of the variance, with PC1 reflecting the trade-off between hydraulic efficiency and mechanical support and PC2 representing the trade-off between high embolism resistance and strong pit flexibility. Regression analysis and structural equation modelling further confirmed that tracheid size positively influenced Ks, whereas the traits DWT, D_r, and TSR have influenced Ks indirectly. All traits failed to show significant phylogenetic associations. Pearson\'s correlation analysis demonstrated strong correlations between most traits and longitude, with the notable influence of the mean temperature during the driest quarter, annual precipitation, precipitation during the wettest quarter, and aridity index.
CONCLUSIONS: Our results showed that xylem anatomical traits demonstrated considerable variability across phylogenies, consistent with the pattern of parallel sympatric radiation evolution and global diversity in spruce. By integrating the anatomical structure of the stem xylem as well as environmental factors of origin and evolutionary relationships, our findings provide novel insights into the ecological adaptations of the
Picea genus.