MOLECULAR ANALYSIS OF CACTUS PEAR CULTIVARS

Total DNA and RNA of several cactus fruit cultivars were extracted by using protocol and reactant DNAzol and TRIazol, respectively. DNA was fragmented and randomly amplified via PCR. In the case of RNA, the RT-PCR procedure was used. RAPDs and RT-PCR products were put on 2% agarose gel and visualized. Four olygoprimers were tested. A band of ≈400 bp of nucleotidic length was detected with no differentiated bands among cactus fruit cultivars. Complementary DNA was generated using specific primers of Hsp70 RNAm from all nopal cultivars. The length of this DNA was ≈300 bp which verified the gene identity. The greatest gene expression was obtained with ‘Morada’, ‘Blanca Cristalina’, ‘Pelon Apastillado’ and ‘Burrona’. Several nopal proteins reacted to anti-bean and anti-HeLa polyvalent antibodies, which showed conserved epitopes between both species. The random PCR amplification gave rise to a same-size DNA fragment for all cultivars. Since such fragment did not allowed cultivar classification, the use of more primers in the procedure is recommended. The DNA pattern allowed us to characterize some cultivars due to the presence of differentiated protein bands.