title: Effect of cryopreservation on apple genetic resources at morphological, chromosomal, and molecular levels.
abstract: Shoot tips of three apple genotypes, namely, Malus pumila cv. M26, Gala, and Hokkaido No. 9, were successfully cryopreserved using a modified encapsulation-dehydration method. As a result, in addition to a high survival rate and regeneration rate, the capacity of shoots regenerated from cryopreserved samples to root was enhanced. Eight M26 single-bud sibling lines were used to assess genetic stability. Although cytological examination revealed a ploidy difference in the noncryopreserved control, the ploidy constitution remained relatively stable during the period of cryopreservation. Amplified fragment length polymorphism (AFLP) assay was performed to detect DNA-level variation. No change in DNA fragment pattern and number was observed between the control and the cryopreserved samples. In addition, methylation-sensitive amplified polymorphism (MSAP) assay was carried out to investigate the DNA methylation status during the period of cryopreservation. It was found that cryopreservation induced a decrease in DNA methylation level.
authors.affiliation: National Key Laboratory of Crop Genetic Improvement, Wuhan 430070, People's Republic of China. yjcxhao@hotmail.com
authors.forename: Y J
authors.initials: YJ
authors.lastname: Hao
authors.forename: Q L
authors.initials: QL
authors.lastname: Liu
authors.forename: X X
authors.initials: XX
authors.lastname: Deng
mesh_terms: D001483:Base Sequence; D002875:Chromosomes / Q000235:genetics; D015925:Cryopreservation; D019175:DNA Methylation; D018744:DNA, Plant / Q000737:chemistry / Q000235:genetics; D017343:Genes, Plant; D027845:Malus / Q000235:genetics* / Q000502:physiology; D008967:Molecular Biology; D018520:Plant Shoots / Q000235:genetics / Q000502:physiology; D011003:Ploidies; D011110:Polymorphism, Genetic; D012038:Regeneration
chemical_list: D018744:DNA, Plant