Kaity A, Ashmore S E, Drew R A, Dulloo M E
School of Biomolecular and Physical Sciences, Griffith University, Brisbane, Australia.
Plant Cell Rep. 2008 Sep;27(9):1529-39. doi: 10.1007/s00299-008-0558-1. Epub 2008 May 27.
A vitrification based cryopreservation technique for storage of in vitro shoot tips of papaya has been tested to ensure applicability across a range of genotypes and to assess the stability of both genotype and phenotype of such clonal material following cryopreservation. Shoot tips of 12 genotypes were cryopreserved, recovery rates were determined and resultant plants were screened for genetic and epigenetic changes. Genomic DNA structure was explored using polymerase chain reaction (PCR) based randomly amplified DNA fingerprinting (RAF), and methylation patterns were monitored using the amplified DNA methylation polymorphism (AMP) PCR technique. Plantlets were recovered following cryopreservation in all but one genotype and recovery rates of 61-73% were obtained from six genotypes. The regenerated plantlets showed varying levels of genomic DNA modifications (0-10.07%), and methylation modifications (0.52-6.62%) of detected markers. These findings have not been reported previously for papaya, and indicate some genotype dependent variability in DNA modifications occur following cryopreservation which may result in somaclonal variation.
一种基于玻璃化的番木瓜离体茎尖冷冻保存技术已经过测试，以确保其适用于一系列基因型，并评估冷冻保存后此类克隆材料的基因型和表型稳定性。对12个基因型的茎尖进行了冷冻保存，测定了回收率，并对所得植株进行了遗传和表观遗传变化筛选。使用基于聚合酶链反应（PCR）的随机扩增多态性DNA指纹图谱（RAF）探索基因组DNA结构，并使用扩增的DNA甲基化多态性（AMP）PCR技术监测甲基化模式。除一个基因型外，所有基因型在冷冻保存后均获得了再生植株，六个基因型的回收率为61%-73%。再生植株的检测标记显示出不同水平的基因组DNA修饰（0%-10.07%）和甲基化修饰（0.52%-6.62%）。这些发现此前尚未在番木瓜中报道，表明冷冻保存后会出现一些依赖基因型的DNA修饰变异性，这可能导致体细胞克隆变异。
