Transformation of mango somatic embryos by biobalistics

In order to genetically transform mango by biobalistic, somatic embryos of the varieties Haden, Madame Francis and Kent were bombarded. The maximum dose of PPT that somatic embryos survive was determined by exposing them in Gamborg, Miller y Ojima media containing 0, 0.5, 1 and 2mg/l PPT during 3 months and subculturing every month to evaluate fresh and dry weight. The embryos were bombarded with the plasmid CAMBIA 3201 with genes GUS y BAR, using two tungsten particle sizes (0.7 and 1.3mum), pressure of 80psi, bombardment distances of 10 and 16.5cm, and 5mug of DNA. Embryos were selected using 0.5mg/l PPT as selective agent. Particle size Of 0.7mum and the bombardment distance of 16.5cm were selected. After 3 months of selection in the indicated PPT concentrations, selected clones of the Kent variety survived all concentrations, while non-transformed embryos survived only at 0.5mg/1. Haden and Madame Francis varieties were sensitive to the bombardment and selection conditions, and did not survive the process. Embryo survival was 4%, and 3 clones per 0.5g of tissues bombarded were regenerated. Enzymatic activity of transient expression of the GUS gene was observed and the incorporation of the GUS and BAR genes was demonstrated by means of PCR.