Determining the Genes for Distyly in Turnera

Heterostyly promotes outbreeding and reduces pollen wastage. Distylous species have two mating types: L-morph and S-morph plants, which are genetically determined by the S-locus. It was hypothesized that the S-locus carries at least three tightly linked genes constituting a supergene. The S-locus genes responsible for distyly in Turnera had not been determined. Using deletion mapping and chromosome walking, the S- and s-haplotypes of the S-locus were constructed. Three hemizygous genes, TsSPH1, TsYUC6, and TsBAHD occur only on the S-haplotype and appear to determine S-morph characteristics. TsSPH1 is expressed in filaments, TsYUC6 in anthers, and TsBAHD in styles. A long-homostyle mutant (Drh) did not possess TsBAHD while another long-homostyle mutant (Mhomo-H) possessed a substitution mutation in TsBAHD. Short-homostyle mutants did not express TsSPH1. The incompatibility system of Turnera joelii possessed a mutation that appears to be linked to S-locus. A possible mechanism of incompatibility is discussed which involves brassinosteroids and auxins.

Author dc:creator

• Hamam, Hasan Jihad

Advisor dc:contributor.advisor

• Shore, Joel S

• Molecular biology

Statement dc:rights

• Author owns copyright, except where explicitly noted. Please contact the author directly with licensing requests.

Language dc:language

en

Handle dc:identifier.uri

http://hdl.handle.net/10315/36742

OAI identifier oai:identifier

oai:yorkspace.library.yorku.ca:10315/36742