title: Cryopreservation of Citrus madurensis zygotic embryonic axes by vitrification: importance of pregrowth and preculture conditions.
abstract: The role of pregrowth and preculture treatments in terms of both medium composition and exposure duration on survival of embryonic axes of Citrus madurensis after cryopreservation using the vitrification procedure was investigated. The optimal pregrowth treatment for excised embryonic axes was a 3-day treatment with 0.1M sucrose. Preculture was also essential in increasing survival after cryopreservation. Among the various media and treatment durations evaluated, a 24h-preculture of embryonic axes on medium with 0.3M sucrose and 0.5M glycerol was found to be optimal. Using these pregrowth and preculture conditions followed by treatment at 25 degrees C for 20 min each with a loading solution (0.4M sucrose + 2.0M glycerol) and then the PVS2 vitrification solution, direct immersion in liquid nitrogen, rapid rewarming, unloading in a 1.2M sucrose solution for 20 min and transfer of embryonic axes on recovery medium, 82.5% survival and regrowth without intermediary callus formation were obtained with C. madurensis embryonic axes.
authors.affiliation: International Plant Genetic Resources Institute (PGRI), Regional Office for Asia, Pacific and Oceania, P.O. Box 236, UPM Post Office, 43400 Serdang, Selangor Darul Ehsan, Malaysia. e.cho@rda.go.kr.
authors.forename: E G
authors.initials: EG
authors.lastname: Cho
authors.forename: Y L
authors.initials: YL
authors.lastname: Hor
authors.forename: H H
authors.initials: HH
authors.lastname: Kim
authors.forename: V R
authors.initials: VR
authors.lastname: Rao
authors.forename: F
authors.initials: F
authors.lastname: Engelmann
mesh_terms: D002957:Citrus / Q000196:embryology*; D015925:Cryopreservation / Q000379:methods*; D003470:Culture Media / Q000494:pharmacology*; D005990:Glycerol / Q000494:pharmacology; D012639:Seeds / Q000187:drug effects*; D013395:Sucrose / Q000494:pharmacology; D015996:Survival Rate; D013997:Time Factors
chemical_list: D003470:Culture Media; D013395:Sucrose; D005990:Glycerol