Cryopreservation of Hybrid Pinus elliottii × P. caribaea

The cryopreservation of embryogenic cultures within operational forestry proves to be a crucial tool, to store clones without loss of juvenility, while field tests, to identify genotypes with significant genetic gain, are being conducted. Besides several conifers species have been cryopreserved till now, only few studies have been reported for hybrid species. The interspecific pine hybrid, P. elliottii var. elliottii x P. caribaea var. hondurensis has a major economic importance mainly in South America, West Africa and Australia. The hybrid superiority appears to be derived from a complementary recombination of traits from the two parental species–growth rate and high yield of resin production from P. caribaea var. hondurensis, combined with wind-firmness, adaptability to wet sites, high wood-density and stem straightness of P. elliottii var. elliottii. This chapter describes a complete cryopreservation procedure for embryonal mass of the hybrid P.elliottii var. elliottii x P. caribaea var. hondurensis, and a methodology to analyse the ploidy stability by flow cytometry.