Phylogenetic reconstruction of Genisteae (Fabaceae): a look at quinolizidine alkaloid distribution Authors: Sarah Hunter, Brian Sedio, Domingos Cardoso, Tracey A. Ruhlman and Robert K. Jansen Abstract:             Quinolizidine alkaloids, or QAs, are naturally occurring chemical compounds unique to certain groups of plants, including the legume tribe Genisteae. This tribe contains several kinds of Lupinus grains, which grow readily in nutrient poor soils in a diverse range of climates, serving as an interesting potential economic crop. The QAs in many plants in Genisteae can act as a double-edged sword, with one edge providing a natural defense mechanism against pests, like aphids, which can hurt grain yield and spread plant diseases. On the other edge, QA concentration in grain tissue must be kept below the regulated industry threshold, which can be a challenge. Since there have been surprisingly few attempts at constructing a complete phylogeny for Genisteae, many relationships among genera remain unresolved. This study aims to build a phylogeny on which to assess the distribution of QAs. Currently, 45 species representing 26 genera have been obtained. So far, tissue has been sampled and genomic data has been collected from 17 taxa representing 10 genera, with plastid, mitochondrial, nuclear, and chemical data for each. The plastomes have been assembled, and mitogenome assembly and low-copy nuclear gene retrieval is underway. The assembled plastomes have been found to be colinear with an average size of 125,738 base pairs.  The smaller plastome size reflects that fact that Genisteae is a member of the inverted repeat lacking clade. Phylogenies will be constructed using markers from all three genomes (plastid, mitochondrial, and nuclear) and QAs will be plotted on the tree in order to examine their phylogenetic distribution. So far, a maximum likelihood tree of the plastomes has found Lupinus forming a clade, while Genista appears sister to Gonocytisus in a separate clade. Meanwhile, Dichilus and Melolobium have diverged at the base of Genisteae, and are sister to each other. These results agree with previous phylogenetic studies, and support the Lupinus clade and the Cytisus-Genista complex. Additionally, the Argyrolobium group, traditionally including Argyrolobium, Melolobium, and Dichilus, is at the base of Genisteae, in its predicted position. When the QAs are plotted, the Lupinus clade shows a pattern of sparteine and lupanine production, while the taxa from the Cytisus-Genista complex tends toward cytisine. These results represent a progress report and the data included are part of a larger project that will include representative species from all genera of Genisteae and outgroups from other tribes in the genistoid clade.