P. Lashermes et al., Genetic linkage map of Coffea canephora: effect of segregation distortion and analysis of recombination rate in male and female meioses, GENOME, 44(4), 2001, pp. 589-596
Two complementary segregating plant populations of Coffea canephora were pr
oduced from the same clone. One population (DH) comprised 92 doubled haploi
ds 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. E
leven linkage groups that putatively correspond to the 11 gametic chromosom
es of C. canephora were identified. The mapped loci included more than 40 s
pecific sequence-tagged site markers, either single-copy RFLP probes or mic
rosatellites, that could serve as standard landmarks in coffee-genome analy
ses. 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 exhibi
ting a very pronounced degree of distortion was especially high in the DH p
opulation. This observation is consistent with the hypothesis of strong zyg
otic selection among the DH population. The recombination frequencies in bo
th populations were found to be almost indistinguishable. These results off
er evidence in favour of the lack of significant sex differences in recombi
nation in C. canephora.