Prospective Targeted Recombination and Genetic Gains for Quantitative Traits in Maize
Prospective Targeted Recombination and Genetic Gains for Quantitative Traits in Maize
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DOI：
10.3835/plantgenome2016.11.0118
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发表时间：
2017-07-01
期刊：
影响因子：
4.2
通讯作者：
Bernardo, Rex
中科院分区：
文献类型：
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作者：
Bernardo, Rex
成簇规则间隔短回文重复序列（CRISPR）技术的进步已经允许在酵母（酿酒酵母）中的特定DNA序列中进行靶向重组。我的目标是确定靶向重组的选择增益是否足够大，以保证在植物中开发靶向重组技术。两种玉米数量性状的全基因组标记效应使用实验来鉴定在给定杂交中将使每条染色体遗传增益最大化的靶重组点。在交配的B73 × Mo17群体中进行非靶向重组，从180个重组自交系中选择最好的自交系导致测交产量增加7.1%。在10条玉米染色体中的每一条上具有一个靶向重组导致产量的预测增益为15.3%。因此，与非靶向重组相比，靶向重组的预测相对效率（RETargeting）为（0.153除以0.071）= 212%。对于B73 x Mo17群体中的其他五个性状和45个其他玉米杂交种中的四个性状，RETargeting值的范围为105%至600%。目标重组点在性状和杂交组合之间存在差异。当每条染色体的靶向重组数量从一个增加到两个时，预测增益增加。总体而言，这些结果表明，定向重组可以加倍玉米数量性状的选择增益，定向重组技术的发展是值得的。目前的标记辅助育种程序的经验性实验需要验证每染色体的预测收益。
Advances in clustered regularly interspaced short palindromic repeats (CRISPR) technology have allowed targeted recombination in specific DNA sequences in yeast (Saccharomyces cerevisiae). My objective was to determine if the selection gains from targeted recombination are large enough to warrant the development of targeted recombination technology in plants. Genomewide marker effects for quantitative traits in two maize (Zea mays L.) experiments were used to identify targeted recombination points that would maximize the per-chromosome genetic gains in a given cross. With nontargeted recombination in the intermated B73 x Mo17 population, selecting the best out of 180 recombinant inbreds led to a 7.1% gain for testcross yield. Having one targeted recombination on each of the 10 maize chromosomes led to a predicted gain of 15.3% for yield. Targeted recombination therefore led to a predicted relative efficiency (RETargeted) of (0.153 divided by 0.071) = 212% of targeted recombination compared with nontargeted recombination. For the five other traits in the intermated B73 x Mo17 population and for four traits in 45 other maize crosses, the RETargeted values ranged from 105 to 600%. The targeted recombination points differed among traits and crosses. Predicted gains increased when the number of targeted recombinations per chromosome increased from one to two. Overall, the results suggested that targeted recombination could double the selection gains for quantitative traits in maize and that the development of targeted recombination technology is worthwhile. Empirical experiments with current marker-assisted breeding procedures are needed to validate the per-chromosome predicted gains.