Burg K, Helmersson A, Bozhkov P, von Arnold S
Austrian Research Center Seibersdorf GmbH, Department of Bioresources, A-2444 Seibersdorf, Austria.
J Exp Bot. 2007;58(3):687-98. doi: 10.1093/jxb/erl241. Epub 2007 Jan 19.
Genotypic instability is commonly observed in plants derived from tissue culture and is at least partly due to in vitro-induced stress. In this work, the issues of whether genetic instability induced by in vitro stress varies among families and if genetic instability influences the adaptation to in vitro conditions and embryo development have been addressed. By comparing the stability of four variable nuclear microsatellite loci in embryogenic cultures and zygotic embryos of Pinus sylvestris, a significant difference in genetic stability among families was found. In six out of 10 families analysed, the level of genetic stability was similar between somatic and zygotic embryos. However, for the rest of the families, the mutation rate was significantly higher during somatic embryogenesis. Families showing a low genetic stability during establishment of embryogenic cultures had a higher embryogenic potential than those which were genetically more stable. In contrast, embryo development was suppressed in genetically unstable families. The relatively high mutation rates found for some families might reflect the plasticity of the families to adapt to stress, which is important for widely distributed species such as Pinus sylvestris.
基因型不稳定在源自组织培养的植物中普遍存在，并且至少部分是由于体外诱导的胁迫。在这项工作中，研究了体外胁迫诱导的遗传不稳定是否在不同家系间存在差异，以及遗传不稳定是否影响对体外条件的适应和胚胎发育等问题。通过比较欧洲赤松胚性培养物和合子胚中四个可变核微卫星位点的稳定性，发现不同家系间的遗传稳定性存在显著差异。在分析的10个家系中的6个中，体细胞胚和合子胚的遗传稳定性水平相似。然而，对于其余家系，体细胞胚胎发生过程中的突变率显著更高。在胚性培养物建立过程中显示出低遗传稳定性的家系比那些遗传上更稳定的家系具有更高的胚性潜力。相反，遗传不稳定的家系中胚胎发育受到抑制。一些家系中发现的相对较高的突变率可能反映了这些家系适应胁迫的可塑性，这对于像欧洲赤松这样分布广泛的物种很重要。
