Institute for Biodiversity and Ecosystem Dynamics, Universiteit van Amsterdam Amsterdam, The Netherlands.
Institute for Biodiversity and Ecosystem Dynamics, Universiteit van Amsterdam Amsterdam, The Netherlands ; NERC, Centre for Ecology and Hydrology Wallingford, UK.
Ecol Evol. 2014 Jun;4(12):2395-409. doi: 10.1002/ece3.1060. Epub 2014 May 17.
The development of stress-tolerant crops is an increasingly important goal of current crop breeding. A higher abiotic stress tolerance could increase the probability of introgression of genes from crops to wild relatives. This is particularly relevant to the discussion on the risks of new GM crops that may be engineered to increase abiotic stress resistance. We investigated abiotic stress QTL in greenhouse and field experiments in which we subjected recombinant inbred lines from a cross between cultivated Lactuca sativa cv. Salinas and its wild relative L. serriola to drought, low nutrients, salt stress, and aboveground competition. Aboveground biomass at the end of the rosette stage was used as a proxy for the performance of plants under a particular stress. We detected a mosaic of abiotic stress QTL over the entire genome with little overlap between QTL from different stresses. The two QTL clusters that were identified reflected general growth rather than specific stress responses and colocated with clusters found in earlier studies for leaf shape and flowering time. Genetic correlations across treatments were often higher among different stress treatments within the same experiment (greenhouse or field), than among the same type of stress applied in different experiments. Moreover, the effects of the field stress treatments were more correlated with those of the greenhouse competition treatments than to those of the other greenhouse stress experiments, suggesting that competition rather than abiotic stress is a major factor in the field. In conclusion, the introgression risk of stress tolerance (trans-)genes under field conditions cannot easily be predicted based on genomic background selection patterns from controlled QTL experiments in greenhouses, especially field data will be needed to assess potential (negative) ecological effects of introgression of these transgenes into wild relatives.
培育耐胁迫作物是当前作物育种的一个日益重要的目标。更高的非生物胁迫耐受性可以增加从作物向野生近缘种基因渗入的可能性。这与关于新的可能设计为提高非生物胁迫抗性的转基因作物的风险的讨论特别相关。我们在温室和田间实验中研究了非生物胁迫 QTL，在这些实验中，我们将栽培生菜品种 Salinas 与其野生近缘种 L. serriola 的重组自交系暴露于干旱、低养分、盐胁迫和地上竞争下。莲座叶末期的地上生物量被用作特定胁迫下植物性能的替代指标。我们在整个基因组中检测到了非生物胁迫 QTL 的镶嵌图，不同胁迫的 QTL 之间几乎没有重叠。鉴定出的两个 QTL 簇反映了一般的生长情况，而不是特定的胁迫反应，与早期研究中发现的与叶形和开花时间有关的簇重合。同一实验（温室或田间）内不同胁迫处理之间的遗传相关性通常高于不同实验中施加的同一类型胁迫之间的遗传相关性。此外，田间胁迫处理的效果与温室竞争处理的效果比与其他温室胁迫实验的效果更相关，这表明竞争而不是非生物胁迫是田间的主要因素。总之，根据温室受控 QTL 实验中的基因组背景选择模式，难以预测田间条件下耐胁迫（转）基因的渗入风险，特别是需要田间数据来评估这些转基因向野生近缘种渗入的潜在（负面）生态影响。
