Cotton leafroll dwarf virus (CLRDV) is a significant aphid-transmitted Polerovirus, causing yield loss in cotton globally, leading to symptoms like leaf reddening/rolling, stunting, maroon stems, and bushy tops through asymptomatic infection. CLRDV, which belongs to the family Solemoviridae, is an economically important phytopathogen that causes considerable growth reduction, yield losses, and fiber quality deterioration in cotton. In this study, the CLRDV investigation ensued in cotton samples collected from fields in the Tashkent Region, Uzbekistan. Total RNA extraction came from symptomatic plants, with polymerase chain reaction (PCR) assays performed using specific primers targeting the coat protein (CP) gene of the virus. Several cotton samples reached positive identification for the CLRDV, with the resulting amplicons sequenced to determine the viral nucleotides’ composition. Based on sequence data, the obtained isolate, as deposited in the GenBank database, had the name UZKIB-1. Phylogenetic analysis revealed the UZKIB-1 shared 96.58% nucleotide identity with CLRDV isolates Henan and CN-S5 (China) and Q3514 (Thailand). Eleven key mutations also succeeded in their detection, indicating ongoing evolutionary divergence within regional CLRDV populations. The results confirmed the presence of CLRDV in Uzbekistan, which will contribute to understanding its genetic diversity and epidemiological significance.

Keywords: Cotton leafroll dwarf virus, field surveys, RT-PCR, coat protein gene, phylogenetic analysis, Tashkent Region

Key findings: Cotton leafroll dwarf virus (CLRDV) detection was successful in various cotton samples collected from the Tashkent Region, Uzbekistan, using molecular analysis. The nucleotide sequence of the UZKIB-1 isolate showed 96.58% identity with CLRDV isolates Henan and CN-S5 (China) and Q3514 (Thailand). Phylogenetic analysis and the identification of 11 mutations revealed ongoing genetic divergence within the CLRDV population in Uzbekistan.