油松地理种群针叶形态解剖与生理指标遗传变异分析

Genetic variation of needle morphology and anatomical traits and physiological traits among Pinus tabuliformis geographic populations

【目的】针叶作为松树生命活动的重要器官,其不同地理种群的形态解剖特征与生理指标的关联尚待阐明,两者间联系可以为认识油松适应性变异提供新的视角。【方法】本研究在对来自油松全分布区不同生境的8个地理种群田间对比试验基础上,分析了4年生苗木次生针叶形态解剖指标、蒸腾与光合生理指标变异及两类指标间的相关关系。【结果】(1)针叶粗细、维管束、气孔和树脂道指标在地理群体间存在显著遗传变异;(2)各生理指标在地理种群间有极显著遗传差异;(3)针叶的净光合速率、蒸腾速率和胞间CO2浓度与形态解剖指标均存在不同紧密程度的正相关;(4)种群的胞间CO2浓度与产地年降水和1月均温与年降水比值呈显著正相关,气孔限制值与年降水量和1月均温/年降水量成显著负相关;(5)种群针叶的气孔线数与经度成显著正相关,而树脂道数与经度显著负相关,但与海拔成显著正相关;树脂道面积和叶肉面积比值与经度和纬度成显著负相关。【结论】遗传相对稳定的针叶形态解剖指标差异可在一定程度上反映地理种群间的光合生理差异,种群间存在针叶气孔量和调节能力随降水量及其维持力减低而提高趋势,树脂道数量及相对截面积随降水量降低而降低的适应性进化趋势。该发现为认识针叶形态解剖特性与光合生理指标关系,松种的适应性进化以及遗传改良提供了理论参考。

[Objective]Needles are the important organs of physiological activities in pine species,but the relationship between morphological and anatomical characteristics and physiological traits of diffenent geographical populations are still unclarified.Thus,assessing the association between the two kinds of traits could provide a new perspective for understanding the adaptive variation of Pinus tabuliformis.[Method]Based on the common garden test of 8 geographic populations which collected in different habitats from the whole distribution area of Pinus tabuliformis,we assessed the variation of morphological and anatomical traits,transpiration and photosynthetic physiological traits of secondary needles of 4-year-old seedlings,and evaluated the correlation between traits.[Result](1)Significant genetic variations were found among geographical populations in needle thickness,vascular bundle,stomatal and resin canal traits;(2)significant genetic diversity of physiological traits was found among geographical populations,except for water use efficiency;(3)the net photosynthetic rate,transpiration rate and intercellular CO2 concentration were positively correlated with morphological and anatomical traits;(4)the intercellular CO2 concentration of populations was significantly positively correlated with the annual precipitation and the average temperature of January/annual precipitation,the stomatal limitation value was significantly negatively correlated with annual precipitation and average temperature of January/annual precipitation;(5)the number of stomatal lines was significantly positively correlated with longitude,while resin canal number was significantly negatively correlated with the longitude but was significantly positively correlated with the altitude.Resin canal area/mesophyll area was significantly negatively correlated with longitude and latitude.[Conclusion]Variation of needle traits could reflect the photosynthetic physiological diversity among geographical populations.The number of needle stomata and regulation capacity of stomata would increase with the decreased precipitation,and the change of the number of resin canal mesophyll area.This study provided a theoretical reference for understanding the relationship between the anatomical and anatomical characteristics of the needles and photosynthetic physiological traits,and adaptive evolution of the pine species and genetic improvement.