First report of a 16SrII‐C phytoplasma associated with <i>Artemisia sieberi</i> witches’‐broom disease in Iran

Artemisia sieberi (Asteraceae) is an important perennial plant that common in the pastures, mountains and deserts of Iran. In 2019, A. showing little leaf, yellowing, internode shortening witches’-broom symptoms (Fig. 1) were observed around Abarkooh (Yazd province, Iran). The disease incidence was up to 5%. Total DNA extracted from 0.2 g fresh midrib tissue 10 diseased five symptomless plants tested for presence phytoplasma by direct PCR using P1/P7 primers nested R16F2n/R16R2 (Lee et al., 1998). Expected amplicons 1.8 1.25 kb obtained all symptomatic but not asymptomatic plants. yielded same RFLP patterns as those 16SrII-C subgroup 1998) after restriction with AluI, HhaI, HinfI, HpaII, MseI RsaI enzymes. Three products cloned sequenced. sequences identical a consensus sequence deposited GenBank (Accession No. MZ151480). Sequence comparison BLAST analysis showed highest identity members ‘Candidatus Phytoplasma aurantifolia’ species (e.g. MH363612 KJ442846). Phylogenetic neighbour-joining method (MEGA software version 6.0) confirmed clustered within 16SrII group clade, closest strains affiliated 2). Computer-simulated 17 endonucleases iPhyClassifier (https://plantpathology.ba.ars.usda.gov/cgibin/resource/iphyclassifier.cgi) pattern derived 16S rRNA gene resembled reference 16Sr II, C (AJ293216), similarity coefficient 0.99. occurrence previously reported Iran on Daucus carota, Medicago sativa, Prunus dulcis, Vicia faba (Siampour 2019), Alhagi maurorum (Esmaeilzadeh-Hosseini & Salehi, 2021), P. armeniaca (Rasoulpour 2019) persica (Salehi 2020). Previous studies have shown Circulifer haematoceps can transmit phytoplasmas; this leafhopper polyphagous could feed sieberi, which may act reservoir host strains. Association 16SrII-D strain has been Hormozgan (Hemmati Nekoohi, 2019). To our knowledge first report new This paper part results project no. 100-11-81-108 approved supported Agricultural Research, Education Extension Organization (AREEO), Ministry Agriculture,