Editing Avocado (section)

===Propagation and rootstocks===
[[File:GrowingAvocadoFromSeed.JPG|thumb|A common technique to germinate avocados at home is to use toothpicks poked into the avocado pit to suspend the pit partially in water.]]
[[File:Persea americana (Avocado) Sprout 08May2010.JPG|thumb|upright|Young avocado sprout]]

Avocados can be propagated by seed, taking roughly four to six years to bear fruit, although in some cases seedlings can take 10 years to come into bearing.<ref>{{cite book|last=Boning|first=Charles|title=Florida's Best Fruiting Plants: Native and Exotic Trees, Shrubs, and Vines|year=2006|publisher=Pineapple Press, Inc.|location=Sarasota, Florida|page=33}}</ref> The offspring is unlikely to be identical to the parent cultivar in fruit quality. Prime quality varieties are therefore propagated by grafting to [[rootstock]]s that are propagated by seed (seedling rootstocks) or by [[layering]] (clonal rootstocks). After about a year of growing in a greenhouse, the young rootstocks are ready to be grafted. Terminal and lateral grafting is normally used. The [[scion (grafting)|scion]] cultivar grows for another 6–12 months before the tree is ready to be sold. Clonal rootstocks are selected for tolerance of specific soil and disease conditions, such as poor soil aeration or resistance to the soil-borne disease (root rot) caused by ''[[Phytophthora cinnamomi]]''. Advances in cloning techniques that can produce up to 500 new plants from a single millimetre of tree cutting have the potential to increase the availability of rootstocks.<ref>Hughes, Megan [https://www.abc.net.au/news/rural/2021-06-07/innovation-smashes-avocado-wait-times/100184924 Avocado tree wait times smashed thanks to world-first rootstock trial] ''ABC News'', 7 June 2021. Retrieved 5 October 2020.</ref>

Commercial avocado production is limited to a small fraction of the vast genetic diversity in the species. Conservation of this genetic diversity has relied largely on field collection, as avocado seeds often do not survive storage in seed banks. This is problematic, as field preservation of living cultivars is expensive, and habitat loss threatens wild cultivars. More recently, an alternate method of conservation has been developed based on cryopreservation of avocado somatic embryos with reliable methods for somatic embryogenesis and reconstitution into living trees.<ref>O'Brien, Christopher, Jayeni CA Hiti-Bandaralage, Alice Hayward, and Neena Mitter. "Avocado (Persea americana Mill.)." In Step Wise Protocols for Somatic Embryogenesis of Important Woody Plants, pp. 305–328. Springer, Cham, 2018.</ref><ref>Nichols, Jennifer [https://www.abc.net.au/news/rural/2020-09-10/avocados-preservation-science-cryopreservation/12643822 Avocadoes of the future look secure thanks to Queensland student Chris O'Brien's cryogenics work] ''ABC News'', 10 September 2020. Retrieved 5 October 2020.</ref>