<i>Cedrus atlantica</i> pollen morphology and investigation of grain size variability using laser diffraction granulometry

The morphology and size variability of pollen grains of <i>Cedrus atlantica</i> were investigated using a novel approach employing laser diffraction granulometry. We provide new insights into size variability and present high-quality light microscopy (LM) and scanning electron microscopy (SEM) imagery of <i>Cedrus atlantica</i> pollen. Grains have an average size of 59.1 ± 4.0 µm, measured on millions of grains from 91 samples. Analysis showed there is high variability of grain size within individual samples, although variability between samples is not significant. We found no significant relationships between grain size and climate (including temperature, precipitation and aridity), and suggest that grain size of fossil <i>Cedrus</i> pollen would not be a good proxy for climate reconstruction. Grain size may be influenced by a number of complex factors such as genome size or adaptations to support wind pollination, while variability within individual samples may result from the irregular development of pollen. The laser diffraction method produced repeatable, robust measurements on millions of pollen grains which are highly correlated with measurements taken using LM (<i>r</i> = 0.91, p = 0.002). Where grain size information is crucial for pollen identification, for developing isolation techniques for geochemical analysis, for investigating climatic and environmental influence, or for investigating links between genomes and grain size, particle size analysis by laser diffraction provides a reproducible and robust method for quickly determining pollen grain size on many samples.本研究采用一种新颖的激光衍射粒度分析法（laser diffraction granulometry），对大西洋雪松（*Cedrus atlantica*）花粉粒的形态与尺寸变异性展开了系统探究。本研究为该物种花粉的尺寸变异性提供了全新认知，并公开了大西洋雪松花粉的高质量光学显微镜（Light Microscopy, LM）与扫描电子显微镜（Scanning Electron Microscopy, SEM）成像数据。研究基于91份样本中的数百万粒花粉，测得其平均粒径为59.1 ± 4.0 微米。分析结果显示，单份样本内部的花粉粒径存在较高变异性，但不同样本间的变异性并不显著。本研究未发现花粉粒径与气候要素（包括气温、降水量及干旱度）之间存在显著关联，据此提出：雪松属（Cedrus）化石花粉的粒径不宜作为古气候重建的可靠替代指标。花粉粒径可能受多种复杂因素调控，例如基因组大小或适应风媒传粉的演化特征；而单份样本内部的粒径变异性，则可能源于花粉发育的不规则性。激光衍射粒度分析法可对数百万粒花粉实现可重复且稳健可靠的粒径测量，其结果与光学显微镜测量结果高度相关（相关系数r=0.91，p=0.002）。当花粉粒径信息对花粉鉴定、地球化学分析的样本分离技术开发、气候与环境影响研究，或基因组与粒径间关联的探究至关重要时，激光衍射粒度分析法可为大量样本的花粉粒径快速测定提供一种可重复且稳健可靠的技术方案。

搜集汇总

背景与挑战

背景概述

该数据集研究了北非雪松（Cedrus atlantica）花粉的形态和粒度变异性，采用激光衍射粒度法进行创新分析，提供了高质量显微镜图像和粒度数据（平均59.1 ± 4.0 µm）。研究发现花粉粒度在样本内部变异性高，但与气候因素无显著关联，表明化石花粉粒度不适合作为气候重建的代理，同时验证了激光衍射方法在花粉研究中的可靠性和效率。