Leveraging the inherent genetic diversity conserved in plant resource collections is key to new crops, new cultivars, and adapted germplasm with improved traits that provide food security for a growing population, remain productive amidst rapid climate change, meet shifting consumer demands, and enhance sustainability and efficiency. The USDA National Plant Germplasm System manages large and genetically diverse plant collections representing crop plant species and many of crop wild relatives (CWR) that have significant impacts on crop production. In this Special Topic Session hosted by the Federal Partners Interest Group, scientists of the Agricultural Research Service (ARS) will discuss the current efforts and future perspectives on the restoration and utilization of germplasms and CWR at the USDA with a special focus on fruit, nut, and beverage crops.
Coordinator(s)- Lisa Tang, USDA-ARS Appalachian Fruit Research Station, Kearneysville, WV, United States
Moderator(s)- Lisa Tang, USDA-ARS Appalachian Fruit Research Station, Kearneysville, WV, United States
- Matthew Mattia, USDA-ARS U. S. Horticultural Research Laboratory, Fort Pierce, FL, United States
Speaker/Participant(s)- Lisa Tang, USDA-ARS Appalachian Fruit Research Station, Kearneysville, WV, United States
Introduction of the Federal Partners special session (5 mins) - Gayle Volk, USDA, Fort Collins, Colorado, United States
The USDA-ARS National Plant Germplasm System Strategic Plan: A roadmap to conserve and utilize U. S. plant genetic resources (15 mins)
Summary: The USDA-ARS National Plant Germplasm System (NPGS) conserves more than 620, 000 accessions of plant genetic resources of crops and crop wild relatives which annually distribute 200, 000+ samples globally. As directed by the 2018 Farm Bill, an NPGS Strategic Plan was developed to address the backlogs in maintenance, characterization, and to enhance utilization. This presentation will provide information about the impacts of the NPGS and details about the NPGS Strategic Plan, which, when funded, will result in: 1) More plant germplasm maintained disease-free, securely backed up, and readily available; 2) Expanded knowledge of the intrinsic genetic variation and high-value traits in NPGS collections; and 3) New plant germplasm with valuable traits acquired, safeguarded and developed. This presentation is authored by Gayle M. Volk (USDA), Marilyn L. Warburton (USDA), Moira Sheehan (Cornell University), Christina Walters (USDA), Stacey Estrada (USDA), Glenn Hanes (USDA), Jim McFerson (USDA), and Peter K. Bretting (USDA-retired). - Chris Gottschalk, USDA-ARS Appalachian Fruit Research Station, Kearneysville, WV, United States
Into the wild: utilization of wild crop relatives the USDA ARS apple pre-breeding program (15 mins)
Summary: - Nahla Bassil, USDA-ARS National Clonal Germplasm Repository, Corvallis, OR, United States
Crop wild relatives of temperate fruits at the Corvallis Genebank: Uses and prospects (10 mins)
Summary: - Michael Hardigan, USDA-ARS, Corvallis, OR, United States
Crop wild relatives of temperate fruits at the Corvallis Genebank: Uses and prospects (10 mins)
Summary: - Tracie Matsumoto, USDA-ARS Daniel K. Inouye Pacific Basin Agricultural Research Center, Tropical Plant Genetic Resources and Disease Research Unit, Hilo, HI, United States
Sub-Tropical/tropical Fruit, Nut, and Beverage Clonal Repository in Hilo, Hawaii (15 mins)
Summary: The National Clonal Germplasm Repository for Tropical Fruit, Nut and Beverage Crops is located in Hilo, Hawaii and is a part of the National Germplasm Repository System and USDA ARS DKI PBARC Tropical Plant and Genetic Resources Unit. The repository is responsible for collecting, maintaining, evaluating, and distributing germplasm of tropical/subtropical fruit and nut crops. Crops include Pineapple (Ananas), Breadfruit (Artocarpus), Starfruit (Averrhoa), Peach palm (Bactris), Pili nut (Canarium), Papaya (Carica and Vasconcellea), Coffee (Coffea) Longan (Dimocarpus), Litchi (Litchi), Macadamia (Macadamia), Acerola (Malpighia), Rambutan and Pulasan (Nephelium), and Guava (Psidium). In addition to the field and greenhouse collections, we are actively investigating new methods to propagate and effectively manage the collections. We work to characterize the collection for resistance to pest and diseases and genetically characterize the germplasm to determine potential gaps for future collections. - Qingyi Yu, USDA-ARS Daniel K. Inouye Pacific Basin Agricultural Research Center, Tropical Plant Genetic Resources and Disease Research Unit, Hilo, HI, United States
Exploring germplasm diversity to understand the domestication process of papaya (15 mins)
Summary: Papaya (Carica papaya L.), originating and domesticated in southern Mexico and Central America, is widely cultivated in tropical and subtropical regions due to its nutritional benefits and the commercially significant proteolytic enzyme, papain. While wild papaya yields small, seedy fruits with minimal edible flesh, domesticated papaya varieties can weigh over five pounds. Wild papaya populations are exclusively dioecious, whereas cultivated papaya is predominantly gynodioecious, although certain dioecious cultivars exist. In this study, we conducted whole-genome resequencing of 86 diverse papaya accessions, comprising 63 cultivars and 23 wild accessions. To identify regions undergoing selection during domestication and improvement, we scanned for areas exhibiting a drastic reduction in nucleotide diversity in cultivars compared to wild accessions. Our results suggest that papaya domestication involved selecting fruit quality traits such as taste and flesh color. Moreover, we re-sequenced the male-specific region of the Y (MSY) in 24 wild males and the hermaphrodite-specific region of the Yh chromosome (HSY) in 12 cultivated hermaphrodites. The Yh sequence is highly similar to one Y haplotype (MSY3), exclusive to wild dioecious populations in the north Pacific region of Costa Rica. The low MSY3-Yh divergence suggests that hermaphrodite papaya resulted from human domestication.
