Compatibility between wild and cultivated common bean (Phaseolus vulgaris L.) genotypes of the Mesoamerican and Andean gene pools: Evidence from the inheritance of quantitative characters

The extent and distribution of incompatibility between gene pools (Mesoamerican and Andean) and evolutionary classes (wild, landrace and bred) of the common bean (Phaseolus vulgaris) was explored by seeking anomalous values of highly heritable quantitative traits in the progeny of crosses. Clear incompatibility (no progeny or sterile or deformed progeny) was shown by 28 crosses in a 12-parent wild × bred diallel cross, and 37 crosses in a 12-parent landrace × bred diallel cross. Incompatibility was particularly common in the progeny of certain genotypes, but was not consistently associated with the division between gene pools or evolutionary classes. When crosses showing clear incompatibility were eliminated from the data, days to flowering, number of seeds per pod, log (weight per seed) and seed roundness in the F₁ generation gave a good fit to an additive-dominance model, confirming that there is no overall tendency to incompatibility between the gene pools. There was a division between the gene pools with regard to log (weight per seed), as expected, but there was no such division, with regard either to the means of the parent lines or the distribution of the statistics V _r and W _r (which indicate the distribution of dominant alleles between genotypes), for the other quantitative variables. Differences between reciprocal crosses were strikingly widespread, and appeared generally to be due to cytoplasmic effects or cytoplasmic × nuclear interactions rather than maternal effects, indicating that the direction in which a cross is made may have a perceptible effect on the progeny that can be obtained from it. This revised version was published online in July 2006 with corrections to the Cover Date.