Population genetics of cycas necrotic stunt virus and the development of multiplex RT-PCR diagnostics.

Cycas necrotic stunt virus (CNSV) has an extensive host range and is detected in an accelerated pace around the globe in several agricultural crops. One of the plant species affected is peony (Paeonia lactiflora Pall.). The virus is asymptomatic in most peony cultivars, but there have been reports of symptoms in others. It is thus important to study CNSV and its population structure to gain insights into its evolution and epidemiology. The outputs of this study, in addition to the in-depth analysis of the virus population structure, include the development of a multiplex RT-PCR detection protocol that can amplify all published CNSV isolate sequences; allowing for accurate, reliable detection of the virus and safeguarding its susceptible, clonally-propagated hosts.

The population structure of the secovirid lychnis mottle virus based on the RNA2 coding sequences.

Lychnis mottle virus (LycMoV), family Secoviridae, is one of several viruses recently detected in peony. Given the high prevalence of the virus in the more than 300 samples tested, the population structure of the virus was studied using 48 isolates representing at least 20 cultivars and collected from major producing and propagating states in the United States. The homogeneity of the United States population, based on data from the RNA2 coding region, along with phylogenetic analyses of all publicly available sequences point to the dissemination of the virus through propagation material rather that active vector-mediated transmission.