title: Maize Germplasm Conservation in Southern California's Urban Gardens: Introduced Diversity Beyondex situandin situManagement.
abstract: Contemporary germplasm conservation studies largely focus onex situandin situmanagement of diversity within centers of genetic diversity. Transnational migrants who transport and introduce landraces to new locations may catalyze a third type of conservation that combines both approaches. Resulting populations may support reduced diversity as a result of evolutionary forces such as genetic drift, selection, and gene flow, yet they may also be more diverse as a result of multiple introductions, selective breeding and cross pollination among multiple introduced varietals. In this study, we measured the amount and structure of maize molecular genetic diversity in samples collected from home gardens and community gardens maintained by immigrant farmers in Southern California. We used the same markers to measure the genetic diversity and structure of commercially available maize varieties and compared our data to previously reported genetic diversity statistics of Mesoamerican landraces. Our results reveal that transnational dispersal creates an opportunity for the maintenance of maize genetic diversity beyond its recognized centers of diversity.
authors.affiliation: Department of Plant Sciences, University of California, Davis, CA USA.
authors.forename: Joanne M
authors.initials: JM
authors.lastname: Heraty
authors.affiliation: Department of Botany and Plant Sciences, University of California, Riverside, CA USA.
authors.forename: Norman C
authors.initials: NC
authors.lastname: Ellstrand
keywords: Zea mays; biodiversity conservation; community gardens; crop evolution; ethnobotany; genetic resources; germplasm erosion; home gardens; immigrant farmers; urban agriculture