DETECTION AND CHARACTERIZATION OF THE PHYTOPLASMA ASSOCIATED WITH MARIGOLD PHYLLODY IN MEXICO
R.I. Rojas-Martínez, E. Zavaleta-Mejía, I.M. Lee, M. Martini, H.S. Aspiros
Cempazuchil (marigold, Tagetes erecta L.) plants with symptoms of phyllody, virescence, witches’ broom (shoot proliferation), apical dwarfing and yellowing were collected from fields in the States of Puebla, Michoacan, Guanajuato, and Estado de Mexico. They were examined for the presence of phytoplasmas by nested polymerase chain reaction (PCR) using the universal primer pair R16mF2/R16mR1 followed by the primer pair R16F2n/R16R2. Restriction fragment length polymorphism (RFLP) analysis of R16F2n/R16R2-PCR products and the sequencing of the 16S rDNA indicated that the phytoplasma which induces the disease known as “filodia del cempazuchil” (marigold phyllody) belongs to the aster yellows group (16SrI), subgroup B. Our results also indicated that the variety of symptoms shown by diseased Tagetes plants from different States in Mexico were induced by the same phytoplasma.