Detection of Phytoplasma on Indian Fig (Opuntia ficus-indica Mill) in Mexico Central Region

Abstract

Problem statement: The Indian fig (a species of prickly pear cactus), has been known as Nopal, comprises an approximate area of 100,000 ha, in plantations used for human consumption. "Pyramids" Indian fig area located in the northeastern State of Mexico has been an important Indianfig area in the country, with 15810 ha, where a phytoplasma has been consistently present in symptomatic plant. Approach: An unknown symptomatology in the Indian fig (prickly pear cactus) (Opuntia ficus-indica Mill) was analyzed through grafting and a nested-PCR reaction and graft on healthy plants grown in a greenhouse. Results: The symptoms found, deforming, buds proliferation, thickening and heart-shaping in cladodes, with arrested plant growth and deep yellowing of cladodes, were all attributed to the presence of a phytoplasma given the amplification of a 1200 pb fragment of the 16S rRNA gene using primers R16 F2/R2 and R16F2n/R2 and 80% of phytoplasma transmission efficiency of successful grafts. Conclusion: Although the symptoms observed did not completely match those described for this organism in the region, a 1200 pb fragment was amplified and PCR products restriction analysis leading us to assume that the phytoplasma corresponds to subgroup 16Srll, previously reported for other crops in others world regions.