DISSERTATION RESEARCH: Reticulation and chromosomal evolution in Amaryllidaceae tribe Hippeastreae

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This project seeks to examine reticulate evolution in a chromosomally diverse group of Neotropical flowering plants, the Amaryllidaceae (amaryllis family). The generic classification of Amaryllidaceae tribe Hippeastreae, which includes 10-12 genera and ~180 species, including amaryllis, rain lilies, and other ornamentals, remains controversial, despite the horticultural importance of these plants. This group of monocots is putatively descended from an ancient hybridization event, and additional, more recent hybridizations have confounded evolutionary relationships. The main goals are to: 1) assess the extent and nature of reticulate evolution in Hippeastreae; and 2) explore patterns of chromosome evolution in a phylogenetic context. The underlying evolutionary history, or phylogeny, of the group will be investigated with DNA sequences of multiple nuclear genes obtained by next-generation sequencing techniques. Reticulate evolution will be addressed through methods that consider gene tree heterogeneity and network representations of the phylogeny. Chromosomal evolution will be assessed through modeling of chromosome number variation and mapping of cytological characters, including genetic, structural, and numerical differences, onto evolutionary trees. This project will provide general insights into reticulation in plant evolution at different temporal scales and ploidy levels (genome duplication) through an integrative molecular approach.This research will provide the co-PI with significant training opportunities in diverse molecular and cytogenetic techniques, which he will apply as a teacher and researcher in his home country, Chile. Hence, he will contribute to the development of systematics research programs in Chile, where this field currently lacks sufficient expertise. This project will result in a revised classification of Hippeastreae, which will benefit other scientists and horticulturists working with these plants. This classification will be integrated into eMonocot, a global online resource for monocot taxonomy.