Molecular characterization and transmission of safflower phyllody phytoplasma in Iran.

Abstract

SUMMARY Safflower plants with phyllody symptoms were observed in Fars and Yazd provinces of Iran. Affected plants showed floral virescence, phyllody and proliferation, proliferation of axillary buds along the stem and little leaf symptoms. The causal agent (SP) was transmitted from diseased to healthy safflower by grafting and from safflower to safflower and periwinkle by dodder (Cuscuta campestris). The presence of phytoplasmas in diseased plants was shown by direct and nested polymerase chain reaction assays using phytoplasma-specific primer pairs P1/P7 and R16F2n/R2. Restriction fragment length polymorphism (RFLP) analysis of nested R16F2n/R2 primed PCR product (1.2 kb) classified SP phytoplasma in the clover proliferation phytoplasma group (16SrVI). Sequence homology, phylogenetic and putative restriction site analyses of 16S rRNA gene also identified SP phytoplasma as a member of 16SrVI group. On the basis of molecular analyses, SP phytoplasma was most closely related to brinjal little leaf and periwinkle little leaf phytoplasmas, members of subgroup 16SrVI-C.