GENETIC DIVERSITY OF OPUNTIA CULTIVARS USING PCR-RFLP ANALYSIS BASED ON FRUITFULL GENE

Opuntia species, commonly known as “nopal” in Mexico, are interesting under an economic and agronomic point of view; for example, they can be used for food purposes, like in many Mexican cuisine dishes, and also as fresh fruit. Unfortunately, the taxonomic location of the commercial cultivars which is only based on morphological characters is confusing and is not consistent with the molecular analysis (ISSR, RAPD, SSR, DNA sequencing). In this study, the genetic diversity among 30 opuntia genotypes was investigated for the first time by Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) using the primers pair Fruitfull_R1218 and Fruitfull_F131 developed previously in Ficus carica L. The PCR products were digested with AluI, MboI and HaeIII endonuclease restriction enzymes and separated on 6% polyacrylamide gels. A dendrogram was constructed based on Nei and Li/Dice similarity coefficient and the bootstrapping method with 1000 replications was applied. As results, the primers used were considered adequate for the detection of the presence of the Fruitfull gene in the Opuntia cultivars studied here. The obtained PCR products were approximately of 850 pb and the number of fragments digested varied between four and six. On the whole the profiles generated and the UPGMA analysis separated the 30 accessions into 7 groups; the cultivars ‘Torreoja’, ‘Oreja de Elefante’, ‘Roja Azteca’ and the Pitaya accession felt into separated groups. Generally speaking, there was not a trend for groupings depending on the fruit size. The distribution of the cultivars in dendrogram did not correspond to the current taxonomic classification. The PCR-RFPL method was successfully applied since it is simple, has a low cost, and is quicker than other molecular techniques and/or morphological differentiation.