INHERITANCE OF PALE FLOWER, CALYX SPOTTING, AND GLANDULAR PUBESCENCE IN MIMULUS-GUTTATUS X MIMULUS-PLATYCALYX PROGENIES

Despite growing interest in the Mimulus guttatus complex as a model fo r evolutionary studies of wild herbaceous plants, few examples of majo r genes controlling morphological variation have been described. We ex amined the inheritance of several candidate traits in experimental cro sses between the closely related species M. guttatus and M. platycalyx . A pale flower color morph was found to be controlled by a single rec essive gene, designated Pip. Despite bimodal distribution in segregati ng populations, calyx spotting and glandular pubescence failed to cons istently fit Mendelian ratios. However, analysis of the pattern of var iation within F-3 families indicated the presence of a single to few m ajor genes or leading factors responsible for segregation variation fo r both traits, There was no evidence for linkage among loci controllin g these traits.