Polyploidy inference across time scales in the charismatic carnivorous plant genus Drosera L. (Droseraceae, Caryophyllales)

Abstract

In this dissertation I sought to evaluate methods for detecting chromosome number changes of different types and ages, and to develop Drosera as a system for chromosome evolution. This was achieved by using chromosome evolution models to test different rates of chromosome evolution between different subgenera in Chapter 1. In Chapter 2, I inferred the parental lineages of Drosera anglica, a neopolyploid, and in Chapter 3, I explored polyploidy along the backbone of Drosera and inferred the backbone relationship in the genus. I found highly elevated rates of single chromosome change in Drosera subgenus Ergaleium compared to the rest of the genus. By using different phasing techniques instead of relying on de novo assembly, I found that D. anglica is of allopolyploid origin from D. rotundifolia (paternal) and D. linearis (maternal). Findings in Chapter 3 supported five polyploidy events in Drosera and extensive gene tree discordance. The three research topics together suggested that using multiple methods are necessary to tease apart the history of polyploid lineages.