Jiao Yabing, Niklas Karl J, Wang Lin, Yu Kexin, Li Yirong, Shi Peijian
College of Biology and the Environment, Bamboo Research Institution, Nanjing Forestry University, Nanjing, China.
Plant Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY, United States.
Front Plant Sci. 2022 Apr 8;13:860206. doi: 10.3389/fpls.2022.860206. eCollection 2022.
Leaf lamina mass and area are closely correlated with the photosynthetic capacity and competitive ability of plants, whereas leaf age has been demonstrated to affect physiological processes such as photosynthesis. However, it remains unknown whether the lamina mass vs. area scaling relationship is influenced by leaf age, which is important for understanding plant adaptive strategies and, more broadly, resource utilization and growth. We measured the leaf functional traits of five leaf-age groups of × for a total of 1,736 leaves. ANOVA followed by Tukey's honestly significant difference test was used to compare the functional traits among the five leaf-age groups. Reduced major axis regression protocols were used to fit the scaling relationship between lamina mass and area, and the bootstrap percentile method was used to compare the lamina mass vs. area scaling relationships among the leaf-age groups. Lamina area, and the ratio of lamina dry mass to lamina fresh mass increased with increasing leaf age. Lamina fresh mass per unit area, and lamina dry mass per unit area both exhibited a parabolic-like trend as leaf age increased, i.e., at the leaf maturation stage, it showed a slight but significant decline. The phenomenon called diminishing returns were confirmed by each of the five leaf-age groups, i.e., all of the numerical values of the scaling exponents of lamina mass vs. area were significantly greater than 1. There were significant differences in the scaling exponents of lamina mass vs. area for the leaves across different sampling times. The scaling exponents were lower at the early rapid growth stage, indicating a lower cost for increasing leaf area compared to the leaf maturation stage. These data are consistent with leaves undergoing a transition from resource acquisition to resource conservation in the process of their development and growth.
叶片质量和面积与植物的光合能力和竞争能力密切相关，而叶龄已被证明会影响光合作用等生理过程。然而，叶片质量与面积的缩放关系是否受叶龄影响仍不清楚，这对于理解植物的适应策略以及更广泛的资源利用和生长至关重要。我们测量了五个叶龄组的×的叶片功能性状，共1736片叶子。采用方差分析（ANOVA）并随后进行Tukey真实显著差异检验来比较五个叶龄组之间的功能性状。使用主轴回归协议来拟合叶片质量和面积之间的缩放关系，并使用自助百分位数法来比较叶龄组之间的叶片质量与面积缩放关系。叶片面积以及叶片干质量与叶片鲜质量的比值随叶龄增加而增加。单位面积叶片鲜质量和单位面积叶片干质量均随叶龄增加呈现抛物线状趋势，即在叶片成熟阶段，呈现轻微但显著的下降。五个叶龄组均证实了收益递减现象，即叶片质量与面积缩放指数的所有数值均显著大于1。不同采样时间的叶片在叶片质量与面积缩放指数上存在显著差异。在早期快速生长阶段，缩放指数较低，表明与叶片成熟阶段相比，增加叶片面积的成本较低。这些数据与叶片在其发育和生长过程中从资源获取向资源保护的转变一致。
