Detection and Molecular Characterization of Wheat Spindle Streak Mosaic Virus in Winter Cereal Production Areas

Abstract

Wheat spindle streak mosaic virus (WSSMV) was investigated in winter cereal production areas to determine its incidence, distribution, and molecular characteristics in symptomatic wheat (Triticum aestivum L.) fields. Field surveys revealed typical symptoms including spindle-shaped chlorotic streaks, mosaic patterns, stunted growth, and reduced tillering, particularly under cool and moist soil conditions favorable for soil-borne viral transmission. Leaf samples collected from symptomatic and asymptomatic plants were subjected to reverse transcription polymerase chain reaction (RT-PCR) using WSSMV-specific primers, confirming the presence of the virus in a significant proportion of symptomatic samples. Molecular characterization based on coat protein and partial RNA gene sequences revealed nucleotide variability among field isolates, indicating genetic divergence within regional populations. Phylogenetic analysis grouped the isolates within the established WSSMV clade, showing close relationships with previously reported strains from temperate wheat-growing regions, suggesting possible movement through infected planting material or soil-borne vector dissemination. Sequence comparisons revealed conserved genomic regions alongside minor mutations, reflecting limited evolutionary divergence. Disease incidence was strongly associated with poorly drained soils and prolonged low-temperature conditions, which favor vector activity and viral replication. The study highlights the importance of accurate molecular diagnostics for early detection and monitoring of WSSMV in winter cereal systems. These findings contribute to understanding the epidemiology and genetic diversity of WSSMV and emphasize the need for integrated disease management strategies, including use of resistant cultivars, certified seed material, and improved agronomic practices to reduce disease spread and yield losses in winter wheat production systems.