Genetic Diversity of Tobacco Mosaic Virus (TMV) Isolates from Tobacco Growing Fields of Western Anatolia, Türkiye

Abstract

Tobacco mosaic virus (TMV) is an important plant virus in agriculture. It is the first evidence of the existence of viruses in history. Studies on the genetic diversity of the CP gene of TMV, which plays a leading role in host interaction, are limited both in our country and worldwide. Genetic diversity analyses were conducted on ten isolates of the full CP gene region of TMV obtained from the most intensive tobacco cultivation areas in T & uuml;rkiye, and compared with global isolates. TMV infection was detected in 32 out of 300 plants collected from the Aegean and Marmara regions (& Ccedil;anakkale, Bal & imath;kesir, & Idot;zmir, Manisa, U & scedil;ak, Ayd & imath;n and Denizli) between 2019 and 2020 using conventional molecular techniques. To genetically characterize the virus, 10 samples were selected from each region, and the complete CP gene region sequences were determined. The aligned CP gene region sequences of TMV from T & uuml;rkiye and its global isolates exhibited nucleotide homology ratios ranging from 87.7% to 100%, with amino acid ratios ranging from 88.7% to 100%. The T & uuml;rkiye isolates displayed similarity rates of 98.5% to 100% at the nucleotide level and 98.7% and 100% at the amino acid level. In phylogenetic analysis, the 196 known isolates of TMV registered in GenBank, belonging to the CP gene region, were divided into two main clades (I and II) and two subclades (Ia and Ib). T & uuml;rkiye isolates were clustered in the major branch with the main clade I and subclade Ia isolates. Therefore, genetic analyses were performed on the CP gene region isolates obtained from different parts of the world and a wide range of hosts, including the isolates obtained from T & uuml;rkiye. The results showed high genetic stability, similar to many tobamoviruses.