First report of a <i>‘Candidatus</i> Phytoplasma solani’‐related strain (16SrXII‐A) associated with <i>Althaea officinalis</i> yellows disease in Iran

Althaea officinalis (marsh mallow, Malvaceae) is a medicinal plant, the roots, leaves and flowers of which are usually used in traditional medicines many countries, including Iran (Kianitalaei et al., 2019). During survey April 2022, phytoplasma-type disease, tentatively named A. yellows (AOY), was observed patches plants naturally growing Golestan, near Shiraz (Fars province, Iran). In 2-ha surveyed area, disease incidence up to 5%. The characteristic symptoms were shoot proliferation from stems, little deformed leaves, shortened internodes, yellowing, witches’ broom, stunting plant sterility (Fig. 1 & 2). Total DNA extracted five diseased asymptomatic using CTAB procedure (Zhang 1998). To examine presence phytoplasma, samples subjected direct PCR P1/P7 (Lee 1998) nested primer pairs R16F2n/R16R2 (Gundersen Lee, 1996). expected amplicons c. 1,800 1,250 bp (respectively) obtained only plants. All cloned into Escherichia coli DH5α cells InsT/A clone™ product cloning kit (Sinnaclone, Iran) three plasmids recombinant colonies sequenced. sequences identical, consensus sequence deposited GenBank (Accession No. OP572231). A BLASTn search showed that phytoplasma associated with AOY shared highest identity (100%) those Convolvulus arvensis broom strains, members ‘Candidatus Phytoplasma solani’ (Salehi 2019), detected Fars, Lorestan Yazd provinces 2019. Phylogenetic analysis neighbour-joining method (MEGA7 program) strain clustered within 16SrXII group closest 16SrXII-A (‘Ca. P. solani’) subgroup 3). percentage similarity reference for species (AF248959) 99.28%. Iran, ‘Ca. (16SrXII-A) strains have been previously reported several such as grapevine, hemp, alfalfa, tomato bindweed (Siampour 2019); however, our knowledge this first report probably world. authors would like thank head Fars Agricultural Natural Resources Research Education Centre, Shiraz, support encouragement.