en تخصصي Special پژوهشي Original article <div><strong>Background and Aims:</strong> Although <em>little cherry disease</em> (LChD) is considered as one of the main virus diseases of cherry in several countries, however, to date, there is no data on the incidence of LChV-1 in Iran, the main region of commercial sweet cherry production in West Asia.<br> <strong>Materials and Methods:</strong> Sweet cherry orchards in north-west Iran including West Azarbaijan, East Azarbaijan Tehran and Qazvin provinces, were surveyed for <em>Little cherry virus 1</em> (LChV-1) infection. RT-PCR tests of symptomatic leaf samples, using specific primers for LChV-1 coat protein gene (CP). Using CP sequences the phylogenetic tree was constructed and molecular analysis and population differentiation was indicated by different approaches.<br> <strong>Results:</strong> Using specific primers a DNA fragment of the expected size about 500 bp in five out of 43 samples, were amplified. Phylogenetic analysis indicated that the LChV-1 isolates clustered into five groups, which three Iranian isolates fell into GII without a host or geography-based correlation. High nucleotide diversity was determined between the different phylogenetic groups, whereas the within-group diversity of LChV-1 CP gene was evens less. The low nucleotide diversity and high haplotype diversity indicated that the LChV-1 population experienced a bottleneck effect and the population underwent growth after a period of low efficient population size. In addition, the dNS/dS ratios indicate that the GIII is probably under weak positive selection and the GI and GII under strong negative selection. <strong>Conclusions: </strong>This study showed for the first time the incidence of LChV-1 in sweet cherry orchards in Iran, which is putatively associated with various plant disorders<span dir="RTL">. </span></div> Little cherry virus 1 (LChV-1), molecular detection, Iran 1 5 http://journal.isv.org.ir/browse.php?a_code=A-10-71-2&slc_lang=en&sid=1 Reza Pourrahim pourrahim@yahoo.com 10031947532846006934 10031947532846006934 Yes Plant Virus Research Department, Iranian Research Institute of Plant Protection (IRIPP), Agricultural Research, Education and Extension Organization (AREEO), Tehran, Iran. Shirin Farzadfar farzadfar2002@yahoo.com 10031947532846006935 10031947532846006935 No Plant Virus Research Department, Iranian Research Institute of Plant Protection (IRIPP), Agricultural Research, Education and Extension Organization (AREEO), Tehran, Iran.