Strawberry crinkle (SCV) and Strawberry mottle (SMoV) viruses affect yield and physio-biochemical responses of three strawberry cultivars under different seasonal conditions.

BACKGROUND: The current study was performed to evaluate the impact of Strawberry crinkle virus (SCV) and Strawberry mottle virus (SMoV) viruses, in single and mixed infections, on the yield and physio-biochemical traits of strawberry plants with different genetic backgrounds. Accordingly, the virus-free plantlets were produced via meristem culture and were then transplanted in a research field in different seasons. METHODS AND RESULTS: The results indicated that genetic background clearly affects the responses of the strawberry plants to the viral infection. In addition, considering the effects of changing environmental factors, different seasons had significant influences on the strawberry responses to the virus infection. The results indicated that the components indicating destructive effects were significantly higher during the summer season. Reverse transcription-polymerase chain reaction using viral specific primers revealed 345 and 461 bp fragments for SCV and SMoV viruses, respectively, where all plants were positive for studied viruses. The comparison between the influence of SCV and SMoV viruses on the host plants indicated that SCV caused more damaging effects on the strawberry fruit yield and physio-biochemical traits. Simultaneous infection with SCV and SMoV severely impacted the strawberry plants compared with the effect of each virus individually. CONCLUSION: It is recommended to keep the temperature of the greenhouses producing strawberry at the cooler levels to prevent the spreading of the aphid-transmitted viruses.

Iranian Strawberry crinkle cytorhabdovirus variation assessed using its movement protein (P3) gene.

BACKGROUND: Strawberry crinkle virus (SCV) is a member of the genus Cytorhabdovirus, family Rhabdovirida, and order Mononegavirales. SCV affects the production of various strawberry cultivars. In this study we investigated the genetic diversity of SCV in strawberry fields based on P3 (movement protein) gene. METHODS AND RESULTS: The samples were collected from strawberry fields in the Kurdistan Province, Iran. P3 gene from 20 SCV isolates, representing 18 nucleic acid haplotypes, is composed of 729 nucleotides, encoding a protein with 243 amino acids. SCV-P3 sequences shared 98.77%-99.86% nucleotide and 97.5%-100% amino acid sequence identity. Phylogenetic analyses of the new P3 sequences with two previously published SCV-P3 sequences from the Czech Republic showed that there are two major phylogroups (I and II) and three minor phylogroups in the body of the phylogeny, I-1, I-2, II-1. Comparisons of P3 gene sequences revealed a mutational bias, with more differences being transitions than transversions. The ratio of non-synonymous/synonymous nucleotide changes was < 1, indicating that SCV-P3 gene is under predominantly negative selection. CONCLUSIONS: Phylogenetic and sequence identity analyses showed that SCV isolates from Iran are closely related and have not diverged more than 2% based on P3 gene despite geographical separation and strawberry cultivar. This is the first report of the genetic diversity of SCV worldwide.