Editing Recalcitrant seed (section)

== Mechanisms of damage ==
[[Image:Litchi root.jpg|thumb|Germinating [[lychee]] seed with its [[radicle]]]]
The two main mechanisms causing damage to recalcitrant seeds are [[desiccation]] effects on the [[Organelle|intracellular structures]] and metabolic damage from the formation of toxic chemicals such as [[free radical]]s.<ref>{{cite web| last = Berjak| first = Patricia| author-link = Patricia Berjak| author2 = N.W. Pammenter| author3 = J. A. Vozzo Editor| title = Ch 4. Orthodox and Recalcitrant Seeds| work = Tropical Tree Seed Manual| publisher = USDA Forest Service| url = http://www.rngr.net/publications/ttsm/ch4/| format = PDF| access-date = 2010-09-27| archive-date = 2017-07-12| archive-url = https://web.archive.org/web/20170712080912/https://rngr.net/publications/ttsm/ch4| url-status = live}}</ref> An example of the first type of damage would be found in some recalcitrant nontropical [[hardwood]] seeds, specifically the [[acorn]]s of recalcitrant [[oak]]s, which can be stored in a non-frozen state for up to two years provided that precautions are taken against drying. These seeds show deterioration of cell membrane lipids and proteins after as few as 3–4 days of drying.<ref>{{cite journal| last = Connor| first = Kristina F| title = Update on oak seed quality research: Hardwood recalcitrant seeds| journal = Proc. RMRS| volume = P| issue = 33| pages = 111–116| publisher = USDA, [[Rocky Mountain Research Station]]| year = 2004| url = http://www.treesearch.fs.fed.us/pubs/9489| access-date = 2008-01-09| archive-date = 2017-07-02| archive-url = https://web.archive.org/web/20170702224836/https://www.treesearch.fs.fed.us/pubs/9489| url-status = live}}</ref> Other recalcitrant seeds, such as those of the sweet chestnut (''[[Castanea sativa]]''), show oxidative damage resulting from uncontrolled metabolism occurring during the drying process.<ref>{{cite journal| last = Leprince| first = Olivier|author2=J Buitink |author3=F Hoekstra | title = Axes and cotyledons of recalcitrant seeds of Castanea sativa Mill. exhibit contrasting responses of respiration to drying in relation to desiccation sensitivity| journal = J. Exp. Bot.| volume = 50| pages = 1515–1524| publisher = Oxford University Press| year = 1999| doi = 10.1093/jexbot/50.338.1515| issue = 338 | doi-access = free}}</ref>