M. C. Cebrián

Multiplex PCR assay for the simultaneous detection and differentiation of Olpidium bornovanus, O. brassicae, and O. virulentus

A multiplex PCR method has been developed to detect, differentiate, and confirm the morphological identification of three root infecting Olpidium spp.: O. bornovanus, O. brassicae, and O. virulentus. Of the 132 root samples examined, 101 samples were infected by Olpidium spp.. Based on the morphology of resting spores, the presence of O. bornovanus was confirmed in 20.5% of the samples, whereas species identity could not be determined for the remaining samples because they failed to reproduce sexually. With multiplex PCR, it was possible to determine the Olpidium identity of all the infected samples, even when resting spores were not formed. This method was also effective for detecting Olpidium spp. in water samples. In addition, the specificity and sensitivity of multiplex PCR were evaluated. The multiplex PCR method was validated with samples of 9 different crops from 11 countries of America, Europe, and Africa.

Viruses of cucurbits in Panama

The main areas of field-grown cucurbit production in Panama were surveyed for the occurrence and distribution of viruses in the growing seasons of 2006 and 2008. Notably, in 2006 only Melon necrotic spot virus (MNSV) was detected, while Papaya ringspot virus (PRSV) was the most frequent in 2008 in terms of number of fields and samples analysed, followed by Zucchini yellow mosaic virus (ZYMV), Watermelon mosaic virus (WMV) and MNSV. Cucumber mosaic virus (CMV), Squash mosaic virus (SqMV), Cucumber green mottle mosaic virus (CGMMV), Tomato spotted wilt virus (TSWV), Cucumber leaf spot virus (CLSV), Cucurbit yellow stunting disorder virus (CYSDV), Cucurbit aphid-borne yellows virus (CABYV), Beet pseudoyellows virus (BPYV), Beet yellows virus (BYV), and Cucumber vein yellowing virus (CVYV) were not detected . Single and double (PRSV+WMV; PRSV+ZYMV; ZYMV+MNSV) infections were detected in 60% and 40% of the samples tested, respectively. The occurrence and distribution of each virus varied according to the region and cucurbit species.