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白杨无性系叶片水力及经济性状与生物量的关系

来源：花匠小妙招时间：2025-05-05 21:32

摘要：

目的: 探究杨树无性系叶片水力及经济性状与生物量的关系，以期探寻预测无性系生物量的可靠指标，对早期选育高产速生无性系具有指导意义。方法: 以来源于同一父母本具有不同生长速率的8个4年生白杨无性系为研究对象，在生长季（7—9月）测定叶片水力性状（叶片维管水力导度Kleaves HPFM、叶片水力导度Kleaf EFM、叶脉密度VD、导管直径Dv、导管水力直径Dh、气孔密度SD和气孔长度SL）、叶片经济性状（比叶面积SLA、叶片全碳含量C、全氮含量N和全碳氮比C/N），生长季结束时（10月）计算地上部分生物量AGB，分析无性系间生物量、叶片水力性状和经济性状的差异，探究三者间的关系。结果: 无性系间地上部分生物量、叶片水力性状、经济性状存在显著差异。AGB总体排序为：K1>K2>K3>Z2>Z1>M3>Z3>M1，大部分无性系的生长趋势与母体树（8年生）保持一致。与叶经济性状变异系数（2.0%~12.0%）相比，水力性状变异系数范围较大（4.5%~13.2%）。叶片水力性状和经济性状不相关，但二者均与地上部分生物量相关。在水力性状中，Kleaves HPFM、VD、Dv和Dh越大，AGB越高，均呈显著正相关，而SD、SL和Kleaf EFM与AGB无相关性。在经济性状中，SLA和AGB呈显著负相关，而C、N和C/N与AGB无相关性。多元线性回归分析表明，VD是影响地上部分生物量的主要指标（t=2.957）。结论: 白杨无性系具有稳定的生长趋势，且无性系间叶水力及经济性状存在差异。这为找寻预测生物量指标提供了可能。与经济性状相比，水力性状可以较好地预测该无性系的地上生物量，且叶脉密度（VD）可能是预测地上生物量的关键因子。

关键词: 杨树无性系, 种内变异, 叶片水力性状, 叶片经济性状, 地上生物量

Abstract:

Objective: Both leaf hydraulic and economic traits affect biomass accumulation as they can quantify and reflect the ability of plants to acquire water-carbon resources and their trade-off strategies. This study aims to explore the relationship between leaf hydraulic and economic traits and biomass of poplar clones, so as to find a reliable index for predicting clonal biomass, which could have guiding significance for early breeding of high-yield and fast-growing clones. Method: Eight 4-year-old white poplar clones with different growth rates and derived from the same parents (Populus alba 'I-101' × (P. Alba × P. Glandulosa) '84K') were used as the study subjects. Hydraulic traits (leaf vascular hydraulic conductance KleavesHPFM, leaf hydraulic conductance KleafEFM, vein density VD, vessel diameter Dv, hydraulic weighted vessel diameter Dh, stomatal density SD and stomatal length SL) and the economic traits (specific leaf area SLA, leaf total carbon content C, leaf total nitrogen content N, and leaf total carbon/nitrogen ratio C/N) were measured in the growing season (July to September). Above-ground biomass (AGB) was calculated at the end of the growing season (October). Then the variations of biomass, leaf hydraulic and economic traits among the clones were analyzed to investigate the relationships among them. Result: There were significant differences in above-ground biomass, leaf hydraulic and economic traits among the clones. The AGB overall ranked as follows: K1 > K2 > K3 > Z2 > Z1 > M3 > Z3 > M1, suggesting that the growth trend of most clones was consistent with the parent tree (8-year-old). Compared with that of leaf economic traits, the variation coefficient of hydraulic traits was larger (2.0%-12.0% VS 4.5%-13.2%). Leaf hydraulic traits and economic traits decoupled with each other, however, they were both related to above-ground biomass. In terms of hydraulic traits, KleavesHPFM, VD, Dv and Dh increased with AGB, all showing a significant positive correlation. However, SD, SL and KleafEFM were not correlated with AGB. As for economic traits, SLA was significantly negatively correlated with AGB, while C, N and C/N were not correlated with AGB. Further multiple linear regression analysis showed that VD was the main index affecting biomass (t = 2.957). Conclusion: The white poplar clones show a steady growth trend, and there are differences in leaf hydraulic and economic traits among the clones, which would provide a possibility for finding predictive biomass indicators at early growth stage. Compared with leaf economic traits, hydraulic traits can be the better predictors of the aboveground biomass of those clones, with vein density (VD) being the key factor.

Key words: poplar clones, intra-specific variation, leaf hydraulic traits, leaf economic traits, above-ground biomass

中图分类号:

S718