榆林沙区四种常见蒿属植物的花粉形态特征OA

To provide palynological evidence for exploring the allergenicity of Artemisia pollen,inter-specific genetic evolutionary relationships,systematic classification of Artemisia plants,and their in-teractions 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 conduc-ted,including Artemisia ordosica.A.sphareocephala,A.sieversiana,and A.annua.Using scan-ning 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 orna-mentation 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 classifi-cation,and also provide palynological evidence for exploring the evolutionary relationships and aller-gies among the four Artemisia plants with close genetic relationships.