PCR tests to identify Elsinoe australis and E. fawcettii
The causal agents of citrus scab, Elsinoe australis and E. fawcettii (both EU Annexes) cannot be readily distinguished by morphological or cultural characteristics but only by their host range and molecular characteristics (i.e. ITS region sequences). New PCR tests have now been developed to distinguish between E. australis and E. fawcettii. In addition, specific primer pairs were developed to differentiate between the sweet orange (Citrus sinensis) and natsudadai (C. natsudadai) pathotypes within the species E. australis. These PCR methods were successfully used both on fungal cultures and infected plant tissues (directly from fruit and leaf lesions).
Sources
Hyun JW, Peres NA, Yi SY, Timmer LW, Kim KS, Kwon HW, Lim HC (2007) Development of PCR assays for the identification of species and pathotypes of Elsinoë causing scab on citrus. Plant Disease 91(7), 865-870.