Optimization of the marker-based procedures for pyramiding genes from multiple donor lines: I. Schedule of crossing between the donor lines
Optimization of the marker-based procedures for pyramiding genes from multiple donor lines: I. Schedule of crossing between the donor lines
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DOI：
10.2135/cropsci2006.06.0435
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发表时间：
2007-03-01
期刊：
影响因子：
2.3
通讯作者：
Yonezawa, K.
中科院分区：
文献类型：
--
作者：
Ishii, T.;Yonezawa, K.
近年来，人们利用多个供体品系的DNA标记，构建了高度基因重组的品系。在这样的程序中，必须首先产生具有处于杂合状态的所有靶标记的植物。有效的程序进行了讨论。当将基因杂交到特定受体系的遗传背景上时，在供体之间杂交之前，应为每个供体单独进行回交。通过回交产生的植物应在植物结构和配置尽可能对称的时间表中杂交。例如，当产生四个这样的植物（A、8、C和D）时，它们应该以类似（A × 13）×（C × D）的时间表进行杂交，其中A加B的靶标记的数目应该尽可能与C加D的靶标记的数目相似。理想型的时间表在四到八个捐助者的存在。当供体本身在没有回交的情况下进行杂交时，适用一个截然不同的指导原则;它们应该在具有完全串联结构的时间表中进行杂交，其中具有较少靶标记的供体在早期阶段进入时间表。在存在连锁或冗余标记物的情况下，应修改时间表中供体的处置。捐助者的配置方式应尽量减少排斥性联系的发生。给出了高冗余度下的修正公式。
Recent exploitation of DNA markers of desirable trait genes facilitates construction of high-degree, gene-pyramided lines via assembling markers from multiple donor lines. In such a program, a plant that has all the target markers in a heterozygous state must be produced first. Efficient procedures for that are discussed. When pyramiding the genes onto the genetic background of a particular recipient line, the backcross should be performed separately for each donor before the crossing between the donors. The plants produced through the backcross should be crossed in a schedule with structure and disposition of the plants as symmetric as possible. When four such plants (A, 8, C, and D) are produced, for instance, they should be crossed in a schedule like (A x 13) x (C x D) in which the number of target markers of A plus B should be as similar as possible to that of C plus D. Ideal-type schedules in the presence of four to eight donors are presented. A contrastingly different guideline applies when the donors themselves are crossed without the backcross; they should be crossed in a schedule with completely tandem structure in which donors with fewer target markers enter the schedule in earlier stages. The disposition of donors in the schedule should be modified in the presence of linked or redundant markers. Donors should be disposed in a pattern to minimize the occurrence of repulsion linkages. Formulae for the modification under a high redundancy are presented.