Heterostyly is one of the most fascinating adaptations to promote outcrossing in plants (Kappel et al., 2017). In heterostylous species, individuals fall into one of two (sometimes three) categories (called morphs) – ones with the female reproductive organs high up in the flower and the male organs lower down, versus ones with the opposite arrangement of sexual organs. The genus Primula (primroses) has been a major model for studying the genetic basis of heterostyly ever since Darwin’s pioneering work on the topic. To assist in the identification of genes underlying the differential growth of male and female reproductive organs, we have characterized a number of sequences that are closely linked to the morph-determining region in the genome (Nowack et al., 2015).
Using a transcriptomics approach, we have identified the CYP734A50 gene as causing the style-length dimorphism between L-morph (long styles, anthers low down in the flower) and S-morph (short styles, anthers high in the flower) plants (Huu et al., 2016). In addition, we have recently shown that the MADS-box gene GLOBOSA2 is responsible for the difference in anther position between flowers of the two morphs (Huu et al., 2020). Studies into the function of the other genes at the Primula S-locus are ongoing, as are comparative analyses in Amsinckia (Boraginaceae). 
Lenhard lab 