New homozygous lines are usually developed from biparental crosses. To my knowledge, biparental and multiparental crosses have not been directly compared as breeding populations. My objective in this simulation study was to determine whether a set of several biparental populations or a single multiparental population is superior in terms of genetic gain and diversity of the best ensuing lines. Multiparental populations were simulated from p = 4, 6, and 8 parents and were compared with the corresponding p(p – 1)/2 biparental populations (i.e., diallel). Each of 250 quantitative trait loci had p alleles. Parental selection was mimicked via a Better Half model, wherein only the better crosses (e.g., four out of six with p = 4) were made. Genetic gains were equal between the Better Half model and the full diallel despite the larger population size with the latter. Current timelines for cultivar development in different species impose a limit on the number of generations available for creating multiparental populations, and the results indicated only a minimal (if any) increase in genetic gain when lines were developed from multiparental populations instead of biparental populations. The main benefit from multiparental populations was a better retention of genetic diversity among the selected lines. It remains to be seen whether this higher diversity among new lines from multiparental populations would lead to larger or more-sustained gains in future lines.

中文翻译：

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品系发育中的多亲群体：遗传增益、多样性和实际限制

新的纯合系通常由双亲杂交发展而来。据我所知，双亲和多亲杂交还没有直接作为育种种群进行比较。我在这个模拟研究中的目标是确定一组几个双亲种群或一个多亲种群在遗传增益和最佳随后品系的多样性方面是否优越。多 亲种群由p = 4、6 和 8 个亲本模拟，并与相应的p ( p – 1)/2 双亲种群（即双亲种群）进行比较。250 个数量性状基因座中的每一个都具有p等位基因。通过 Better Half 模型模拟父母选择，其中只有更好的杂交（例如，六分之四与p = 4) 制作。尽管后者的种群规模较大，但 Better Half 模型和全双列模型之间的遗传增益相等。当前不同物种的栽培品种发展时间表对可用于创建多亲种群的世代数施加了限制，结果表明，当从多亲种群而不是双亲种群开发品系时，遗传增益的增加只有很小（如果有的话）。多亲种群的主要好处是更好地保留了所选品系之间的遗传多样性。来自多亲种群的新品系之间的这种更高的多样性是否会导致未来品系的更大或更持续的收益还有待观察。