Family trees: Roots and resilience

Authors: Grauke, Larry

Submitted to: Pecan South
Publication Type: Trade Journal
Publication Acceptance Date: 5/15/2019
Publication Date: 6/1/2019
Citation: Grauke, L.J. 2019. Family trees: Roots and resilience. Pecan South. 52(6):12-21.

Interpretive Summary: The US pecan industry is young, compared to most tree crops. The pecan is an unusual example of a North American native tree that has become a worldwide crop. The early pecan industry grew out of the native forest with several factors contributing to its historic development: a nutritious, high quality product that was in demand; proximity of that crop to pioneer markets in both the east (New Orleans) and the west (San Antonio); and the development of grafting, which allowed production of large nuts and increased uniformity. The first grafted pecan orchard was propagated by the slave gardener Antoine at Oak Alley Plantation, LA, in 1846 https://cgru.usda.gov/CARYA/PECANS/Centennial.HTM). Since individual pecan trees can live longer than 200 years, there are trees in native groves that are older than the commercial pecan industry. The effort to select and propagate large, thin-shelled nuts led to the first generation of pecan cultivars. In the March edition of Pecan South, I told stories of the origins of some important cultivars for the western region, 'Western' and 'Riverside' and tied those stories to currently developing techniques of genetic analysis. Now, I want to return to the story of the Florida pecans, whose stories are embedded in the nursery industry as rootstocks, as well as scion cultivars, and as parents in breeding and development. As before, these are the stories of our pecan growing families, with direct links to our current industry, and they cross national borders that are still in contention. These stories highlight the role of plant introductions in contributing regionally adapted cultivars. They have implications for our use of the diversity in the USDA ARS National Collection of Genetic Resources for Pecans and Hickories (NCGR-Carya) for cooperatively breeding and selecting better cultivars and rootstocks in the future.

Technical Abstract: Differences in the preference and performance of nursery seedstock selections call for evaluating the genetic foundations of Florida pecan cultivars. Distribution maps showing geographic origination of 400 native and seedling pecans are provided. Historical documentation beginning in 1893 in the form of logbook entries, nut sample measurements and photographs, historic nursery propagation records, and inventory records of USDA ARS Repository orchards are presented. Plant introductions that were accidental and cryptic will be illuminated by developing genomic tools, incorporating broad international cooperation and promoting future progress for the industry.