An improved real-time PCR system for broad-spectrum detection of Didymella bryoniae, the causal agent of gummy stem blight of cucurbits

Evolutionary history and variation in host range of three Stagonosporopsis species causing gummy stem blight of cucurbits

“…Didymella bryoniae) had been described as the causal agent, but we now know that S. cucurbitacearum, Stagonosporopsis caricae, and a distinct lineage, described here as Stagonosporopsis citrulli, can cause the disease. The two genetic groups, RGI and RGII that were detected in previous studies (Keinath et al 1995;Somai et al 2002), overlap with S. citrulli and S. cucurbitacearum, respectively, while S. caricae, previously described solely as a papaya pathogen, overlaps with isolates that could not be assigned to either group (Kothera et al 2003;Santos et al 2009;Ling et al 2010 species has been reported (Aveskamp et al 2010), but until now, S. caricae had been considered as a pathogen of papaya and S. cucurbitacearum as a pathogen mostly of cucurbits (Boerema et al 2004); however, S. cucurbitacearum has been reported as a pathogen of other plant families, including Solanaceae and Caricaceae (Boerma et al 2004), but the specimens or the specific references are not referred to, so it is difficult to determine if these isolates were truly S. cucurbitacearum and not S. caricae or another closely-related Stagonosporopsis species. However, it is now apparent that both S. cucurbitacearum and S. caricae generate the same symptoms on cucurbits and that S. caricae produces similar symptoms on papaya (Nishijima 1994;Sitterly & Keinath 1996).…”

Rapid and Sensitive Detection of Didymella bryoniae by Visual Loop-Mediated Isothermal Amplification Assay

“…The occurrence of GSB disease in the greenhouse and in the field may arise from transplantation of latently infected source seedlings, or contamination by the pathogen may occur as a result of inappropriate pruning of unhealthy plants (Keinath, 1996, 2011; Ling et al, 2010). Thus, seedling health testing is a central issue for a large nursery.…”

“…Mycelia were then harvested as described previously (Ling et al, 2010). Muskmelon genomic DNA was extracted from the leaves.…”

“…This SCAR, common to both genotypes of D. bryoniae , was identified in PCR products generated using the DB17 primer set ( Table 2 ) (Ling et al, 2010). According to this conserved SCAR (GenBank accession nos GQ872461 and GQ872462), a set of LAMP primers, comprising two outer primers (DB17RG-F3 and DB17RG-B3), two inner primers (DB17RG-FIP and DB17RG-BIP), and one loop-backward primer (LDB17RG-LB) was designed using the LAMP primer software PrimerExplorer v.4 1 (Eiken Chemical Co., Japan) ( Figure 1 ).…”

Using Ecological Knowledge and Molecular Tools to Develop Effective and Safe Biocontrol Strategies

“…It spreads from temperate to tropical regions of the world (Sitterly & Keinath, 1996). Fruits, leaves and flower scars are invaded by the pathogen and it can also be seed-borne (Lee et al, 1984;Ling et al, 2010;de Neergaard, 1989;Sitterly & Keinath, 1996). By cultivation-independent SSCP fingerprinting of the fungal ribosomal internal transcribed spacer (ITS) region in combination with DNA sequencing and BLAST analysis (Altschul et al, 1997), it was detected as well in roots of oil pumpkin (data not shown).…”