Polymix breeding with parental analysis of progeny: an alternative to full-sib breeding and testing
Polymix breeding with parental analysis of progeny: an alternative to full-sib breeding and testing
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DOI：
10.1007/s001220100627
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发表时间：
2001-11-01
影响因子：
5.4
通讯作者：
Wheeler, N
中科院分区：
文献类型：
--
作者：
Lambeth, C;Lee, BC;Wheeler, N
大多数传统的全同胞杂交和测试设计的实现在后勤上是困难的，昂贵的，遗传增益受到资源可用性的限制。一种替代全同胞杂交和测试的方法可以改善所有这些限制。另一种解决方案是使用许多父本的花粉混合物（PMX），而不是在每个杂交中使用单一花粉。PMX育种易于实施，确保了对被授粉亲本育种价值的良好估计，并提供了增加的遗传增益机会，因为测试的有效亲本组合数量显着增加。然而，PMX育种发现有限的用途，因为近亲繁殖和血统控制丢失。相对便宜的分子标记的发展允许对后代进行父系分析，从而允许完整的谱系控制。我们称此系统为双亲分析的PMX育种（PMX/WPA）。以45个有一定亲缘关系的火炬松（Pinus taeda）第三代种群为研究对象，对PMX/WPA的可行性进行了评价。所有亲本树均在7个叶绿体位点和3个核微卫星位点进行基因分型。所有45个个体都获得了独特的指纹，但由于在繁殖群体中的亲缘关系，不可能从完整的花粉混合中确定后代的父系。包含更多的标记和/或创建避免亲缘关系的杂种和育种群体将解决这个问题。描述了三种PMX/WPA场景，并与传统的全同胞育种和测试系统进行了比较：(1)只对每一代的前（下一代）选择候选者进行父系分析；(2)对PMX杂交中所有的后代测试个体进行父系基因分型，并利用这些数据构建有效的全同胞杂交进行统计分析；(3)像#2一样，将几个PMX杂交的种子混合在一起，以便于温室饲养和后代测试，然后进行母系和父系分析。
Implementation of most traditional full-sib crossing and testing designs is logistically difficult, costly, and genetic gain is constrained by resource availability. An alternative to full-sib crossing and testing can ameliorate all these constraints. The alternative solution is to apply a pollen mix (PMX) of many male parents rather than a single pollen for each cross. PMX breeding is easy to implement, ensures good estimates of breeding values of the parent being pollinated, and provides for increased genetic gain opportunity because of the significantly increased number of effective parental combinations tested. However, PMX breeding has found limited use because inbreeding and pedigree control is lost. The development of relatively inexpensive molecular markers allows for the paternity analysis of progeny, thus allowing full pedigree control. We call this system PMX breeding with parental analysis (PMX/WPA). The feasibility of PMX/WPA was evaluated in a loblolly pine (Pinus taeda) third-generation population of 45 select individuals, among which there was considerable relatedness. All parental trees were genotyped at seven chloroplast and three nuclear microsatellite loci. Unique fingerprints were obtained for all 45 individuals, but unambiguous paternal determinations for progeny from a complete pollen mix would not be possible due largely to relatedness in the breeding population. The inclusion of more markers and/or the creation of polmixes and breeding groups that avoid relatedness would resolve this problem. Three PMX/WPA scenarios are described and compared with conventional full-sib breeding and testing systems: (1) paternity analysis of only the forward (next generation) selection candidates in each generation, (2) paternal genotyping of all progeny test individuals in PMX crosses and using those data to construct the effective full-sib crosses for statistical analysis, and (3) like #2 except mixing seed of the several PMX crosses for ease of greenhouse rearing and progeny testing and then doing maternal and paternal analysis.