Segregation distortion and genome-wide digenic interactions affect transmission of introgressed chromatin from wild cotton species
Segregation distortion and genome-wide digenic interactions affect transmission of introgressed chromatin from wild cotton species
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DOI：
10.1007/s00122-017-2952-y
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发表时间：
2017-10-01
影响因子：
5.4
通讯作者：
Paterson, Andrew H.
中科院分区：
文献类型：
--
作者：
Chandnani, Rahul;Wang, Baohua;Paterson, Andrew H.
本研究报道了陆地棉最远的整倍体近亲--芥棉染色体片段向陆地棉的遗传转化。多位点互作和结构重排影响供体染色体的导入和分离。棉花的野生异源四倍体近缘是一个丰富的遗传多样性来源，可用于遗传改良，但连锁拖累和非孟德尔传递遗传在种间杂交中普遍存在。这些问题需要了解野生供体物种在栽培受体物种中的染色质传播模式。以陆地棉远缘四倍体棉种间杂交为材料，利用216个DNA标记基因座，对陆地棉BC3F_1代35个单株的等位基因保留和BC3F_2群体3202个单株的分离模式进行了研究。供体等位基因在BC3F1中的平均保留率高于预期，而BC3F2分离家系中芥菜等位基因的平均频率低于预期。尽管芥兰等位基因在BC3F1中的保留率高得令人惊讶，但46个基因组区域没有表现出渗入。3号和15号染色体上缺乏内渗的区域与先前报道的可能的小倒位密切相关。具有单基因座分离扭曲的基因座之间以及来自两个亚基因组之一的基因座之间存在着丰富的非线性双基因座互作。结果表明，陆地棉对不同异源四倍体亲缘关系的供体染色质具有不同的渗透性。亚基因组对两个基因座互作的不同贡献暗示了亚基因组在异源四倍体棉花进化中的不同命运。陆地棉×芥棉杂交的传递遗传学揭示了等位基因的相互作用、供体等位基因的固定和选择的限制，以及在作物改良中保持导入染色质的挑战。
This study reports transmission genetics of chromosomal segments into Gossypium hirsutum from its most distant euploid relative, Gossypium mustelinum . Mutilocus interactions and structural rearrangements affect introgression and segregation of donor chromatin.Wild allotetraploid relatives of cotton are a rich source of genetic diversity that can be used in genetic improvement, but linkage drag and non-Mendelian transmission genetics are prevalent in interspecific crosses. These problems necessitate knowledge of transmission patterns of chromatin from wild donor species in cultivated recipient species. From an interspecific cross, Gossypium hirsutum x Gossypium mustelinum, we studied G. mustelinum (the most distant tetraploid relative of Upland cotton) allele retention in 35 BC3F1 plants and segregation patterns in BC3F2 populations totaling 3202 individuals, using 216 DNA marker loci. The average retention of donor alleles across BC3F1 plants was higher than expected and the average frequency of G. mustelinum alleles in BC3F2 segregating families was less than expected. Despite surprisingly high retention of G. mustelinum alleles in BC3F1, 46 genomic regions showed no introgression. Regions on chromosomes 3 and 15 lacking introgression were closely associated with possible small inversions previously reported. Nonlinear two-locus interactions are abundant among loci with single-locus segregation distortion, and among loci originating from one of the two subgenomes. Comparison of the present results with those of prior studies indicates different permeability of Upland cotton for donor chromatin from different allotetraploid relatives. Different contributions of subgenomes to two-locus interactions suggest different fates of subgenomes in the evolution of allotetraploid cottons. Transmission genetics of G. hirsutum x G. mustelinum crosses reveals allelic interactions, constraints on fixation and selection of donor alleles, and challenges with retention of introgressed chromatin for crop improvement.