title: Walnut (Juglans).
abstract: Walnut species are important nut and timber producers in temperate regions of Europe, Asia, South America, and North America. Trees can be impacted by Phytophthora, crown gall, nematodes, and cherry leaf roll virus; nuts can be severely damaged by codling moth and Xanthomonas blight. The long-generation time of walnuts and an absence of identified natural resistance for most of these problems suggest biotechnological approaches to crop improvement. Described here is a somatic embryo based transformation protocol that has been used to successfully insert horticulturally useful traits into walnut. Selection is based on the combined use of the selectable neomycin phosphotransferase (nptII) gene and the scorable uidA gene. Transformed embryos can be germinated or micropropagated and rooted for plant production. The method described has been used to establish field trials of mature trees.
authors.affiliation: Plant Science Department, University of California, Davis, CA, USA.
authors.forename: Charles A
authors.initials: CA
authors.lastname: Leslie
authors.forename: Sandra L
authors.initials: SL
authors.lastname: Uratsu
authors.forename: Gale
authors.initials: G
authors.lastname: McGranahan
authors.forename: Abhaya M
authors.initials: AM
authors.lastname: Dandekar
mesh_terms: D016960:Agrobacterium tumefaciens / Q000166:cytology / Q000235:genetics*; D018929:Cell Culture Techniques; D018920:Coculture Techniques; D003470:Culture Media; D018014:Gene Transfer Techniques; D005819:Genetic Markers; D005822:Genetic Vectors; D018525:Germination; D005966:Glucuronidase / Q000032:analysis; D031324:Juglans / Q000033:anatomy & histology / Q000235:genetics* / Q000254:growth & development; D007612:Kanamycin / Q000494:pharmacology; D012639:Seeds / Q000196:embryology / Q000235:genetics / Q000254:growth & development; D046509:Tissue Culture Techniques; D014170:Transformation, Genetic
chemical_list: D003470:Culture Media; D005819:Genetic Markers; D007612:Kanamycin; D005966:Glucuronidase