To improve an elite soybean line, introgress longer chromosome segments instead of QTL alleles from exotic germplasm. Broadening the diversity of cultivated soybean [Glycine max (L.) Merrill] through introgression of exotic germplasm has been difficult. Our objectives were to (1) determine if introgressing specific chromosome segments (instead of quantitative trait locus alleles) from exotic soybean germplasm has potential for improving an elite cultivar, and (2) identify strategies to introgress and pyramid exotic chromosome segments into an elite cultivar. We estimated genomewide marker effects for yield and other traits in seven crosses between the elite line IA3023 and seven soybean plant introductions (PIs). We then predicted genetic gains from having ≤ 2 targeted recombinations per linkage group. When introgression was modeled for yield while controlling maturity in the seven PI × IA3023 populations, the predicted yield was 8-25% over the yield of IA3023. Correlated changes in maturity, seed traits, lodging, and plant height were generally small but were in the favorable direction. In contrast, selecting the best recombinant inbred (without targeted recombination) in each of the PI × IA3023 populations led to negative or minimal yield gains over IA3023. In one PI × IA3023 population, introgressing and pyramiding only two linkage groups from recombinant inbreds into IA3023 was predicted to achieve an 8% yield gain over IA3023 without sacrificing the performance for other traits. The probability of inheriting intact chromosomes was high enough to allow introgression and pyramiding of chromosome segments in 5-6 generations. Overall, our study suggested that introgressing specific chromosome segments is an effective way to introduce exotic soybean germplasm into an elite cultivar.

中文翻译：

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预测来自外来种质的染色体片段渗入到优良大豆品种中的遗传增益。


为了改良优良大豆品系，从外来种质中渗入更长的染色体片段而不是 QTL 等位基因。通过外来种质渗入来扩大栽培大豆 [Glycine max (L.) Merrill] 的多样性一直很困难。我们的目标是（1）确定来自外来大豆种质的特定染色体片段（而不是数量性状基因座等位基因）的基因渗入是否具有改良优良品种的潜力，以及（2）确定将外来染色体片段基因渗入和金字塔化到优良品种中的策略。我们估计了优良品系 IA3023 和七个大豆植物引种 (PI) 之间的七个杂交中产量和其他性状的全基因组标记效应。然后我们预测每个连锁群有 ≤ 2 个目标重组的遗传增益。当对七个 PI × IA3023 群体的成熟度进行基因渗入建模时，预测产量比 IA3023 产量高 8-25%。成熟度、种子性状、倒伏和株高的相关变化一般较小，但朝着有利的方向发展。相比之下，在每个 PI × IA3023 群体中选择最佳重组近交系（无靶向重组）会导致比 IA3023 的产量增益为负或最小。在一个 PI × IA3023 群体中，仅将来自重组自交体的两个连锁群基因渗入并聚合到 IA3023 中，预计将比 IA3023 实现 8% 的产量增益，而不会牺牲其他性状的性能。遗传完整染色体的概率足够高，足以允许染色体片段在 5-6 代内渗入和金字塔化。 总体而言，我们的研究表明，基因渗入特定染色体片段是将外来大豆种质引入优良品种的有效方法。