Avocado (Persea americana Mill.)

Avocado (Persea americana Mill.) is an ancient tree species belonging to the Order Ranales and Family Lauraceae. At present, the demand for avocado is growing rapidly due to its high nutritional value and reported health benefits. Much of this demand is centred on only a few cultivated varieties despite there being vast genetic diversity in the species. Preservation of germplasm is a proactive approach to address future breeding needs and to safeguard the diversity of cultivated crops including avocado. Present conservation strategies for Avocado (Persea spp.) solely rely on field collections, as seeds are highly heterozygous and recalcitrant to long-term storage. However, these field banks are constantly exposed to abiotic and biotic stresses. Moreover, the size of the gene pool, number of replications and quality of maintenance are restrained by the local environmental conditions, space and funding. In this chapter we present a protocol for cryopreservation of avocado somatic embryos as an alternative to field banks for long-term storage of germplasm. The protocol describes all stages of a vitrification-based cryopreservation and regeneration technique including induction, maintenance, maturation, cryo-treatment and germination of somatic embryos. This in vitro regeneration and storage system for avocado will impose low risk and is a space efficient conservation method that will be beneficial for future improvement of this invaluable horticultural crop