Abstract: Pollen grains of 10 Chinese yam(Dioscorea opposita Thunb.)were observed by scanning electron microscope(SEM).The results showed that the pollen shape of 10 Chinese yam(Dioscorea opposita Thunb.)is spheroidicity with both flat ends and 2 anasulcates.The polar axis length is 11.51 μm(10.02-13.90 μm)and the equatorial axis length is 18.53 μm(16.21-21.05 μm).It is a small pollen(10-25 μm).There were some significant differences on pollen of 10 Chinese yam(Dioscorea opposita Thunb.)in the long polar axis,equatorial axis and P/E ratio respectively.Exine ornamentation is reticulate,foveolate-reticulate,cavernous categories.The result of Q-cluster analysis based on pollen morphology and characteristic indicated that 10 Chinese yam could be classified into three groups when genetic distance was 7.75.The groupⅠincluded Bikeqi Yam and Taoqiang Yam with their small pollen grains,nearly round equatorial view and cavernous exine sculpture.The groupⅡincluded Jiaxiang Yam,Taihuai Yam,Houma Yam,Huilou red peel Yam,Sunfuji Yam and Baoding Yam with medium pollen grain.Taihuai Yam exine sculpture was foveolate-reticulate ornamentation and the other matereils were all reticulate ornamentation.The groupⅢincluded Huaxian Yam and Japan Yam-2 with larger pollen grain and reticulate ornamentation and cavernous ornamentation respectively.

Key words: Chinese yam(Dioscorea opposita Thunb.), SEM, Pollen morphology, Classification

CLC Number: 

• S632.1