Key Message

The tendency of somatic embryogenesis to regenerate plants only from the L1 layer, associated with the spread of chimerism in grapevine, must be carefully considered in the framework of biotechnological improvement programmes.

Abstract

Grapevine is an important fruit crop with a high economic value linked to traditional genotypes that have been multiplied for centuries by vegetative propagation. In this way, somatic variations that can spontaneously occur within the shoot apical meristem are fixed in the whole plant and represent a source of intra-varietal variability. Previously identified inconsistencies in the allelic calls of single nucleotide variants (SNVs) suggested that the Vitis vinifera ‘Nebbiolo’ CVT185 clone is a potential periclinal chimera. We adopted the somatic embryogenesis technique to separate the two genotypes putatively associated with the L1 and L2 layers of CVT185 into different somaclones. Despite the recalcitrance of ‘Nebbiolo’ to the embryogenic process, 58 somaclones were regenerated and SNV genotyping assays attested that the genotype of all them differed from that of the mother plant and was only attributable to L1. The results confirmed that L2 has low or no competence for differentiating somatic embryos. After one year in the greenhouse, the somaclones showed no phenotypic alterations in comparison with the mother plant; however further analyses are needed to identify potential endogenous sources of variation. The tendency of somatic embryogenesis to regenerate plants only from L1 must be carefully considered in the framework of biotechnological improvement programmes in this species.

中文翻译：

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体细胞胚胎发生是剖析葡萄内比奥罗嵌合现象的有效策略

关键信息

在生物技术改进计划的框架中，必须仔细考虑体细胞胚胎发生仅从 L1 层再生植物的趋势，这与葡萄藤中嵌合体的传播有关。

抽象的

葡萄树是一种重要的水果作物，具有很高的经济价值，与几个世纪以来通过无性繁殖繁殖的传统基因型有关。通过这种方式，可以在枝条顶端分生组织内自发发生的体细胞变异在整个植物中被固定，并代表了品种内变异的来源。先前发现的单核苷酸变体 (SNV) 等位基因调用中的不一致表明Vitis vinifera'Nebbiolo' CVT185 克隆是一种潜在的周缘嵌合体。我们采用体细胞胚胎发生技术将假定与 CVT185 的 L1 和 L2 层相关的两种基因型分离成不同的体细胞克隆。尽管 'Nebbiolo' 对胚胎发生过程有抵抗力，但还是再生了 58 个体细胞克隆，并且 SNV 基因分型分析证明所有它们的基因型都与母植物的基因型不同，并且仅归因于 L1。结果证实L2对体细胞胚胎的分化能力低或没有能力。在温室中放置一年后，体细胞克隆与母株相比没有表现出表型变化；然而，需要进一步分析以确定潜在的内源性变异来源。