title: CRYOTHERAPY AS A METHOD FOR REDUCING THE VIRUS INFECTION OF APPLES (Malus sp.).
abstract: BACKGROUND
  There is an urgent need in Kazakhstan for virus-free nursery stock to reinvigorate the industry and preserve historic cultivars. An in vitro collection of apples could be used for virus testing and elimination and to provide virus-free elite stock plants to nurseries.
  
  
  METHODS
  Malus sieversii Ledeb. M. Roem. and Malus domestica Borkh. accessions were initiated in vitro for virus identification and elimination. Reverse transcription and multiplex PCR were used to test for five viruses. PVS2 vitrification was used as a tool for cryotherapy.
  
  
  RESULTS
  Four viruses, Apple chlorotic leaf spot virus (ACLSV), Apple stem pitting virus (ASPV), Apple stem grooving virus (ASGV) and Apple mosaic virus (ApMV) were detected in 17 accessions. Tomato ringspot virus (ToRSV) was not detected. ACLSV affected 53.8% of the accessions, ASPV 30.8%, ASGV 5.1%, and ApMV was found only in 'Aport Alexander'. Cryotherapy produced virus-free shoot tips for seven of nine cultivars tested. Six cultivars had 60-100% elimination of ACLSV.
  
  
  CONCLUSIONS
  An in vitro collection of 59 accessions was established. Virus elimination using cryotherapy produced virus-free shoots for seven of nine cultivars and is a promising technique for developing a virus-free apple collection.
authors.affiliation: Institute of Plant Biology and Biotechnology, Almaty, Republic of Kazakhstan. nata_romadanova@mail.ru.
authors.forename: Natalya V
authors.initials: NV
authors.lastname: Romadanova
authors.affiliation: Institute of Plant Biology and Biotechnology, Almaty, Republic of Kazakhstan.
authors.forename: Svetlana A
authors.initials: SA
authors.lastname: Mishustina
authors.affiliation: Institute of Plant Biology and Biotechnology, Almaty, Republic of Kazakhstan.
authors.forename: D ilyara A
authors.initials: Di
authors.lastname: Gritsenko
authors.affiliation: Institute of Plant Biology and Biotechnology, Almaty, Republic of Kazakhstan.
authors.forename: Madina Y
authors.initials: MY
authors.lastname: Omasheva
authors.affiliation: Institute of Plant Biology and Biotechnology, Almaty, Republic of Kazakhstan.
authors.forename: Nurbol N
authors.initials: NN
authors.lastname: Galiakparov
authors.affiliation: United States Department of Agriculture, Agricultural Research Service, National Clonal Germplasm Repository, Corvallis, OR, USA.
authors.forename: Barbara M
authors.initials: BM
authors.lastname: Reed
authors.affiliation: Institute of Plant Biology and Biotechnology, Almaty, Republic of Kazakhstan.
authors.forename: Svetlana V
authors.initials: SV
authors.lastname: Kushnarenko
mesh_terms: D017679:Cryotherapy / Q000379:methods*; D007623:Kazakhstan; D027845:Malus / Q000502:physiology / Q000821:virology*; D060885:Multiplex Polymerase Chain Reaction; D000069600:Plant Breeding; D010935:Plant Diseases / Q000517:prevention & control* / Q000821:virology; D018520:Plant Shoots / Q000502:physiology / Q000821:virology; D010942:Plant Viruses / Q000502:physiology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D058989:Vitrification