Location: Tropical Crops and Germplasm Research2013 Annual Report
1a. Objectives (from AD-416):
Objective 1: Increase seed and conduct phytosanitary assessments for more than 1,000 NPGS Sorghum and Zea accessions which are subject to quarantine restrictions, so as to make additional certified, pathogen-tested seeds available to users. Objective 2: Regenerate about 8,000 NPGS accessions with few seeds, low viabilities, and adaptations to equatorial latitudes and long-seasons, emphasizing Sorghum, Zea, Vigna, Cucurbita, Leucaena, and Psophocarpus. Record key agronomic traits such as host-plant resistance to biotic and abiotic stresses.
1b. Approach (from AD-416):
Select and treat seed for freedom of signs and symptoms of pathogens; conduct annual disease surveys; inspect and verify status of plants (PPQ); grow quarantined and/or photoperiod-sensitive crops, report new diseases, maintain low pest levels, bag heads prior to anthesis; identify diseases and take regulatory action; record key descriptor information for entry into GRIN; harvest seed and examine for disease symptoms; and return seed to National Plant Germplasm System.
3. Progress Report:
Research in this project is service oriented and assists ARS curators with the introduction of new germplasm, seed regeneration and increase, and recording of descriptor notes for entry into the Germplasm Resources Information Network (GRIN). Accessions of sorghum, corn, cowpea, Leucaena, cucurbits, Ipomoea and winged bean are being regenerated at St. Croix, U.S. Virgin Islands and Isabela, Puerto Rico and descriptor notes for phenotypic traits are being recorded. During the life of this project the following number of accessions were regenerated: 7,111 sorghum, 129 corn, 260 cowpea, 31 cucurbits, 67 Leucaena, 53 winged bean, 19 pearl millet, 2 Abelmoschus, 4 Crotalaria, 7 Ipomoea. In addition, 724 and 265 accessions of quarantined sorghum and corn, respectively, were also seed regenerated. Phenotypic descriptors for all the above accessions were recorded and provided to curators for incorporation into GRIN. Over 1,600 sorghum panicles and 100 cowpea flowers from accessions regenerated at St. Croix and Isabela were photographed, images edited and database tables prepared for the Plant Genetic Resources Conservation Unit, Griffin, GA, for their incorporation into GRIN. Cowpea plant introduction (PI) 441917 was identified as having tolerance to cucumber mosaic virus (CMV) and blackeye cowpea mosaic virus (BlCMV). Cowpea PI’s 582605 and 582674 were identified as possessing tolerance to alkaline soils and significantly higher yield at two locations as compared to other genotypes used in the study. This project is terminating during this annual report cycle and is being replaced by project 6635-21000-052-00D.
1. Seed regeneration and phenotypic characterization of grain crops germplasm for the National Plant Germplasm System (NPGS). Seed of crops must be maintained alive and sufficiently diverse in order for scientists to be able to develop new plant varieties that can resist pests, diseases and environmental stresses. During this fiscal year, a total of 1,212 accessions of sorghum, 42 of photoperiod-sensitive corn, 52 of cowpea, 2 cucurbits, 19 pearl millet, and 4 Ipomoea were planted and seed-regenerated by ARS researchers at St. Croix, U.S. Virgin Islands and Isabela, Puerto Rico, for seed increase and characterization of plant traits. Release of these materials to regional plant introduction stations allowed an expansion of genebanks, maintenance of viable seed, and documentation of important plant traits that are used by scientists working on the improvement of these crops. A total of 82 phenotypic descriptors were recorded for the above crops and sent to curators for incorporation into the Germplasm Resources Information Network (GRIN). Over 50 cowpea flowers from accessions regenerated at Isabela were photographed, images edited and database tables prepared for the Plant Genetic Resources Conservation Unit, Griffin, GA, for their incorporation into GRIN.