榆林沙区四种常见蒿属植物的花粉形态特征

The Pollen Morphology Characteristics of Four Common Mugwort Plants in Yulin Sandy Area

以毛乌素沙地南缘榆林沙区的四种蒿属(Artemisia Linn.)植物花粉为研究对象,采用扫描电镜(SEM)技术,对其花粉形态详细观察。结果表明:四种花粉粒的形态具有高度一致性,符合蒿属花粉的形态特征,同时也表现出一定的种间差异性,经方差分析,极轴、赤道轴长度、其比值P/E及表面纹饰刺长差异显著(P<0.05)。极轴和赤道轴长度排序为大籽蒿>黑沙蒿>白沙蒿>黄花蒿;极轴和赤道轴长度比值P/E排序为黄花蒿>白沙蒿>黑沙蒿>大籽蒿;表面纹饰刺长及由密到疏的排列顺序为:黑沙蒿>白沙蒿>大籽蒿>黄花蒿,依次出现退化。这些种间细微差别可以作为古植物孢粉鉴别和现代植物种间分类的参考依据,也可为探索亲缘关系较近的四种蒿属植物种间进化关系及其过敏提供孢粉学依据。

To provide palynological evidence for exploring the allergenicity of Artemisia pollen,interspecific genetic evolutionary relationships,systematic classification of Artemisia plants,and their interactions with the environment,a detailed observation of the pollen morphology of four commonly seen Artemisia plants in the Yulin sand area at the southern margin of the Mu Us Desert was conducted,including Artemisia ordosica,A.sphareocephala,A.sieversiana,and A.annua.Using scanning electron microscopy(SEM)technology,we have found that the four types of pollen grains have a high degree of morphological consistency,which is in line with the morphological characteristics of Artemisia pollen.They also showed certain interspecific differences.Variance analysis showed that the differences in polar axis length,equatorial axis length,their ratio P/E,and the length of surface ornamentation spines are significant(P<0.05).The order of polar axis and equatorial axis lengths is A.sieversiana>A.ordosica>A.sphareocephala>A.annua;the order of the ratio P/E of polar axis and equatorial axis lengths is A.annua>A.sphareocephala>A.ordosica>A.sieversiana;the length of surface ornamentation spines and the order from dense to sparse is A.ordosica>A.sphareocephala>A.sieversiana>A.annua,showing a trend of degradation.These subtle interspecific differences can serve as a reference for ancient plant sporopollen identification and modern plant interspecific classification,and also provide palynological evidence for exploring the evolutionary relationships and allergies among the four Artemisia plants with close genetic relationships.