进境黑麦草种子中黑麦草腥黑粉菌的鉴定

Identification of Tilletia walkeri from imported ryegrass seeds

从广州 (1997)和天津 (1999)进境的美国黑麦草种子中均发现一种类似中国一类危险性有害生物小麦印度腥黑粉菌 (TilletiaindicaMitra)的冬孢子。其大小分别为 2 8 9～ 4 3 7μm和 2 9 2～ 4 0 2 μm ,淡黄色至暗褐色 ,半透明至不透明 ,球形至亚球形 ,疣状突起常呈钝圆状 ,表面有脊状突起。检疫中常因其与印腥冬孢子极为相似而引起误诊。经形态学特征观察、PCR分析和PCR扩增产物测序分析 ,鉴定为黑麦草腥黑粉菌 (Tilletiawalkeri)。

Teliospores showing morphological features of Tilletia walkeri were found in ryegrass(Lolium)samples,which had been imported from Oregon,The United States of America to Guangzhou in 1997 and Tianjin in 1999,respectively.Based on microscopic observation,the teliospores showed the characteristics as follows:28 9?43 7 μm and 29 2?40 2 μm in diameters,pale yellow to dark brown,opaque to semi opaque,spherical or flatted sperical,domed tuberculate with protruded ornaments on surfaces.Two pairs of primers specific for genes of T.walkeri were used to amplify DNA isolated from germinated teliospores of the ryegrass samples;sequences of 391 bp and 415 bp were produced.Based on these data,the teliospores sampled from the imported ryegrass were identified as T.walkeri.