Genome sequence and detection of peach rosette mosaic virus.

Peach rosette mosaic disease was first described in the 1940s affecting peach and plum. It was later determined that peach rosette mosaic virus (PRMV) is the causal agent of the disease. PRMV, a member of the genus Nepovirus, infects several perennial crops including stone fruit, grape and blueberry as well as several weed species found in orchards around the world. The molecular characterization of the virus is limited to partial genome sequences making it difficult to develop reliable and sensitive molecular detection tests; the reason that detection is routinely performed using ELISA with antibodies risen against a single virus isolate. Given the potential economic impact of the virus and the modes of transmission which, in addition to nematodes, include seed we studied PRMV in more depth using a modified dsRNA extraction protocol to obtain the virus genome. We determined the full nucleotide sequence and developed a protocol that detects conserved regions present in RNA 1 and RNA 2, making it an excellent alternative to the detection protocols used today.

Epidemiology of Blackberry chlorotic ringspot virus.

The pollen- and seed-borne ilarviruses pose a substantial threat to many specialty crops, including berries, rose, and tree fruit, because there are no efficient control measures other than avoidance. The case of Blackberry chlorotic ringspot virus (BCRV) is of particular interest because the virus has been found to be an integral part of blackberry yellow vein disease and is widespread in rose plants affected by rose rosette disease. This study provides insight into the epidemiology of BCRV, including incidence in blackberry and rose; host range, with the addition of apple as a host of the virus; and seed transmission that exceeded 50% in rose. Sensitive detection protocols that can be used to avoid dissemination of infected material through nurseries and breeding programs were also developed.

Epidemiology of Blackberry yellow vein associated virus.

Blackberry yellow vein disease is one of the most important diseases of blackberry in the United States. Several viruses are found associated with the symptomology but Blackberry yellow vein associated virus (BYVaV) appears to be the most prevalent of all, leading to the need for a better understanding of its epidemiology. Efficient detection protocols were developed using end-point and quantitative reverse-transcription polymerase chain reaction. A multi-state survey was performed on wild and cultivated blackberry to assess the geographical distribution of the virus. Two whitefly species, Trialeurodes abutilonea and T. vaporariorum, were identified as vectors and 25 plant species were tested as potential BYVaV hosts. The information obtained in this study can be used at multiple levels to better understand and control blackberry yellow vein disease.