Importance of cucurbits in the epidemiology of Papaya ringspot virus type P

Abstract

Papaya ringspot virus type P (PRSV-P) systemically infects Carica papaya and species belonging to the family Cucurbitaceae. Attempts to recover PRSV-P from naturally infected cucurbit plants grown near or among diseased papaya trees have shown conflicting results worldwide. This study aimed to evaluate the natural infection of cucurbit species grown among and near papaya trees infected with PRSV-P in Brazil. Natural infection of cucurbits with PRSV-P occurred in zucchini squash but not in watermelon and cucumber. However, several attempts to recover PRSV-P from numerous Cucurbita pepo cv. Caserta (zucchini squash) plants grown 5-80 m from diseased papaya trees in the field failed. Mechanical inoculations of Cucurbita pepo cv. Caserta, Cucurbita maxima cv. Exposição (pumpkin), Cucumis sativus cv. Primepack Plus (cucumber) and Citrullus lanatus cv. Crimson Sweet (watermelon) with five Brazilian PRSV-P isolates showed that zucchini squash was the most susceptible species followed by watermelon and cucumber, while pumpkin was not infected. The results confirmed the variable susceptibility of cucurbit species to experimental and natural PRSV-P infection. Given these facts, the control of the disease through roguing should focus mainly on diseased papaya plants, as has been practised successfully in Brazil for many years, and on those cucurbits particularly known to be susceptible to natural infection with PRSV-P.

The wild type of Momordica charantia is not infected by potyviruses that cause disease in papaya and cucurbit crops

“…These practices include the following: the use of virus-free seedlings for new plantings; the eradication of old and abandoned orchards before starting new crops; the avoidance of cucurbit plants, which may harbour the virus within the proximity of the orchard; and, in particular, the roguing of diseased plants by means of systematic inspections of the crops by well-trained personnel (Ventura et al, 2004). Although growers are recommended to avoid the planting of cucurbit plants within or near the orchard, recent studies conducted in Brazil by Mansilla et al (2013) revealed that these species do not have a significant importance on the epidemiology of papaya ringspot disease. The control of PRSV-W and ZYMV relies mainly on the use of resistant/tolerant cucurbit varieties whenever available.…”

Presencia de Papaya ringspot virus (PRSV) en arvenses asociadas a Carica papaya en Colima, México

“…Mexican Journal oF PhytoPatholoGy fuera de cultivos de papayo infectados con PRSV-P utilizando ELISA y RT-PCR (Mansilla et al, 2013). En Florida, se reportó la presencia de PRSV-W en especies vegetales de la familia Cucurbitaceae, afectando los cultivos de pepino, calabaza, melón y sandía; también se detectó como hospedante de maleza, entre las cuales están Momordica balsamina, Melothria pendula y Coccinia grandis (Goyal et al, 2012;Tantiwanich et al, 2014).…”

“…La detección de PRSV mediante DAS-ELISA y RT-PCR en plantas de C. papaya y maleza asociada extensively reported as hosts for PRSV (NoaCarranza et al, 2006;Sreenivasulu and SaiGopal, 2010;Goyal et al, 2012;Mansilla et al, 2013). Phylogenetics (Figure 3) was useful to identify three similar sequence groups.…”

“…This may be due to the fact that C. papaya is susceptible to more than eight phytopathogen viruses such as Papaya apical necrosis virus (PANV), Papaya lethal yellowing virus (PLYV), Papaya Mosaic Virus (PMV), Papaya leaf distortion mosaic virus (PLDMV), among others (Lastra and Quintero, 1981;Brunt et al, 1996), so it may be that the viral symptom may be caused by some of those viruses. -Gopal, 2010;Goyal et al, 2012;Mansilla et al, 2013). La filogenia (Figura 3) permitió identificar tres grupos de secuencias similares.…”

“…In Brazil, a study was conducted to evaluate natural infection of cucurbitaceous species inside and outside of papaya crops infected with PRSV-P using ELISA and RT-PCR tests (Mansilla et al, 2013). In Florida, the presence of PRSV-W was reported in plant species of the family Cucurbitaceae that damage cucumber, squash, melon and watermelon crops; PRSV-W was also reported as a host of Momordica balsamina, Melothria pendula and Coccinia grandis (Goyal et al, 2012;Tantiwanich et al, 2014).…”