Lashermes P, Combes M C, Prakash N S, Trouslot P, Lorieux M, Charrier A
Regional Coffee Research Station, Coffee Board, Andhra Pradesh, India.
Genome. 2001 Aug;44(4):589-96.
Two complementary segregating plant populations of Coffea canephora were produced from the same clone. One population (DH) comprised 92 doubled haploids derived from female gametes, while the other population (TC) was a test cross consisting of 44 individuals derived from male gametes. Based on the DH population, a genetic linkage map comprising 160 loci was constructed. Eleven linkage groups that putatively correspond to the 11 gametic chromosomes of C. canephora were identified. The mapped loci included more than 40 specific sequence-tagged site markers, either single-copy RFLP probes or microsatellites, that could serve as standard landmarks in coffee-genome analyses. Furthermore, comparisons for segregation distortion and recombination frequency between the two populations were performed. Although segregation distortions were observed in both populations, the frequency of loci exhibiting a very pronounced degree of distortion was especially high in the DH population. This observation is consistent with the hypothesis of strong zygotic selection among the DH population. The recombination frequencies in both populations were found to be almost indistinguishable. These results offer evidence in favour of the lack of significant sex differences in recombination in C. canephora.
从同一克隆体培育出了两个互补的分离植物群体，均为咖啡种。一个群体（DH）由92个源自雌配子的双单倍体组成，而另一个群体（TC）是一个测交群体，由44个源自雄配子的个体组成。基于DH群体构建了一个包含160个位点的遗传连锁图谱。确定了11个连锁群，推测它们对应于咖啡种的11条配子染色体。定位的位点包括40多个特定的序列标签位点标记，即单拷贝RFLP探针或微卫星，它们可作为咖啡基因组分析的标准标记。此外，还对两个群体之间的分离畸变和重组频率进行了比较。虽然在两个群体中都观察到了分离畸变，但在DH群体中表现出非常明显畸变程度的位点频率特别高。这一观察结果与DH群体中存在强烈合子选择的假设一致。发现两个群体中的重组频率几乎没有差异。这些结果为咖啡种在重组方面不存在显著性别差异提供了证据。
