Abstract Detail

Charles Heiser Special Contributed Paper Session

Miller, Allison [1], Romero Hernandez, Carolina [2], Hunt, Ken [3].

Relating genetic and phenological variation in pecans (Carya illinoinensis) growing in a common garden.

Crop genetic resources are critical for sustainable agriculture and food security. Pecan (Carya illinoinensis), a native North American species, is prized for its oil-rich, nutritious nuts. Breeding collections housing pecan cultivars and native accessions in a common garden present a valuable opportunity to characterize genetic variation in the species, and to examine genetic and environmental influences on phenological traits. In this study, we use neutral molecular genetic data to: 1) characterize genetic variation in a living collection of pecan trees derived from geographically distinct areas; and 2) test the hypothesis that genetic distance is correlated with phenological difference among trees in the common garden. This work was based on trees housed at the University of Missouri Horticulture and Agroforestry Research Center, which maintains a living collection of 160 pecans (two clones each of 80 named accessions). The accessions include 25 cultivars that resulted from human selection (13 resulting from controlled crosses, 12 representing improved seedlings), and 55 accessions derived from native trees. Eight microsatellite loci were used to estimate genetic variation in the HARC pecan collection. A second, independent dataset was produced using amplified fragment length polymorphism (aflp) data generated with five selective primer pairs. Phenological data including the timing of bud break, leaf flush , and nut maturity were collected over seven years. Mantel tests were used to examine correlations between genetic distance and phenological difference in the common garden. Molecular genetic data demonstrate comparable levels of genetic variation in artificially selected trees and native trees, and are consistent with predictions of multiple geographic origins of artificially selected pecan trees. Preliminary analyses indicate that associations between genetic distance and phenological difference are trait-specific. These data are consistent with previous work conducted in pecan, which found that some phenological traits are influenced primarily by local environmental conditions, while others appear to be under genetic control.

Broader Impacts:

Related Links:
http://www.slu.edu/~amille75

1 - Saint Louis University, Department Of Biology, 3507 Laclede Avenue, St. Louis, MO, 63103, USA
2 - PhD Student-Saint Louis University, Biology, 2118A Cleveland Pl., Saint Louis, MO, 63110, USA
3 - University of Missouri, Center for Agroforestry, Horticulture and Agroforestry Research Center, 203 Anheuser-Busch Natural Resources Building, Columbia, MO, 65211, USA

Keywords:
domestication
crop wild relatives
genetic variation
phenology.

Presentation Type: Oral Paper:Papers for Topics
Session: 03
Location: Lindell D/Chase Park Plaza
Date: Monday, July 11th, 2011
Time: 11:00 AM
Number: 03013
Abstract ID:555