Dissertation Research: Domestication in a Tropical Fruit Tree

Washington University, Saint Louis MO

Investigators

Abstract

Schaal 0105134 Domestication occurs as humans select and cultivate plants from wild populations. In many crop species, the adoption of high-yielding, uniform cultivars has resulted in the abandonment of genetically variable, indigenous varieties. It is well known that during these later stages of domestication, genetic diversity is lost as high-yield crops are developed; however, the fate of genetic variation during the early stages of domestication (prior to intensive plant breeding) is not known. This study examines the process of domestication in a tropical fruit tree, the purple mombin (Spondias purpurea L.), which is believed to be in the early stages of domestication. DNA sequence data will be used to pinpoint the geographic origin of the purple mombin, and to examine relationships among cultivated and wild populations. Genetic variation will be quantified to determine the proportion of total variation captured in the cultivated populations. Recently, much attention has refocused on crops and their wild relatives as concerns mount about the lack of genetic diversity in cultivated species. This proposal will result in a comprehensive assessment of the origin, distribution, and amount of genetic variation in a tropical fruit tree, providing insights into the evolutionary processes involved in the domestication of our cultivated plants. Historical knowledge of cultivated plant populations will yield critical information required for developing conservation strategies.