|Bucklin Comiskey, Sarah|
Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: 4/18/2002
Publication Date: 7/1/2002
Citation: LARTEY, R.T., BUCKLIN COMISKEY, S.A. A PCR protocol for rapid detection of Cercospora beticola in infected sugar beet tissues. PHYTOPATHOLOGY. 2002. V. 12. P. S45. Interpretive Summary: Leaf spot caused by Cercospora beticola. Sacc. is the most important foliar disease of sugar beet. Besides beet leaf residues, other sources of inoculum that initiate disease under optimal conditions is not well understood. We present a PCR based-protocol for rapid isolation and detection of the leaf spot causing pathogen C. beticola. The protocol is based on rapid amplification of actin gene and ITS regions sequences of Cercospora from infected plant tissues. The amplified actin gene segment is then cloned, sequenced and compared with previously determined actin gene sequence in GenBank. The system will enable rapid screening for alternate hosts, including asymptomatic plants.
Technical Abstract: Leaf spot by Cercospora beticola. Sacc. is the most important foliar disease of sugar beet (Beta vulgaris L). The pathogen overwinters as stromata in beet leaf residues. Under optimal conditions, overwintering propagules germinate and produce conidia that are dispersed as primary inoculum to initiate infection in sugar beet. Severe leaf spot occurs even under rotation, suggesting that there are other sources of inoculum such as secondary hosts or weeds. We present an Extract-N-Amp Plant PCR Kit (Sigma)-based protocol for rapid detection and identification of C. beticola in plant tissues. Leaf disks from diseased tissues were homogenized in dilution solution. Without DNA extraction, aliquots of the homogenate were added to PCR reaction and subjected to amplification using the Cercospora actin gene and ITS region based primers. The fragment sizes of amplified products correlated with the expected size of the control DNA extracts from C. beticola cultures. Alignment of sequences of the amplified products confirmed them to be that of C. beticola. The system will enable rapid screening for alternate hosts, including asymptomatic plants.