Occurrence of Cauliflower mosaic virus in different cruciferous plants in Iran

Surveys were conducted to determine the occurrence of Cauliflower mosaic virus (CaMV) in the cruciferous crops grown in the Fars province of Iran, during the summer and early autumn of 2003. Leaf samples were collected from different cruciferous plants (Brassica oleracea var. acephala, B. oleracea var. botrytis, B. oleracea var. capitata, B. oleracea var. italica, and B. rapa) showing mottling, banding mosaic, necrotic spots, malformation and chlorosis symptoms (Fig. 1).

These samples were tested for the presence of CaMV by DAS-ELISA using specific polyclonal antibodies (kindly provided by Dr S. Winter, DSMZ, BBA Messeweg 11/12, As No. 0206 Braunschweig, Germany). Sap from symptomatic leaves was used for the mechanical inoculation of a range of indicator hosts including, B. rapa, B. napus, B. pekinensis, Raphanus sativus (Brassicaceae) and Datura metel (Solanaceae). All of the CaMV isolates tested induced mosaic symptoms on the cruciferous indicator plants, however, one isolate (Ca-Sh1) infected D. matel systemically. All CaMV strains infect a wide range of cruciferous plants but some are also able to infect solanaceous hosts (Schoelz & Shepherd, 1988). The biological and serological data were confirmed by PCR amplification of a DNA fragment of the expected size (approximately 750 bp), corresponding to the CaMV-gene II, using specific primers (Agama et al., 2002).

CaMV is widely distributed in temperate regions and brassica crops tend to become infected wherever they are grown (Shepherd, 1981). CaMV has previously been reported from Iran on oilseed rape (B. napus) (Shahraeen et al., 2003) but to our knowledge, this is the first report of the natural occurrence of CaMV on B. oleracea var. acephala, B. oleracea var. botrytis, B. oleracea var. capitata, B. oleracea var. italica and B. rapa in Iran.