2010 Annual Report
1a.Objectives (from AD-416)
In cooperation with staff at the ARS Plant Genetic Resources Conservation Unit, Griffin, Georgia, conserve and distribute a wide spectrum of sorghum genetic diversity and associated information to researchers and breeders worldwide. Phenotypically evaluate sorghum genetic resources for priority morphological and phenological characters, disease resistance, and other priority agronomic traits, and incorporate data into GRIN and/or other databases.
1b.Approach (from AD-416)
Conduct field seed increase to regenerate approximately 500 sorghum accessions with critically low seed quality or quantity to conserve the collection. Use technical information derived from sorghum germplasm evaluations to assist NPGS staff to aid in the conservation, introduction, and distribution of sorghum germplasm. Phenotypically evaluate the 1,227 sorghum accessions from the Zimbabwe collection and use this information to evaluate genetic diversity for sorghum improvement. Using passport and phenotypic evaluation data develop germplasm subset for disease evaluation to identify ecogeographic regions associated with resistance and develop genetic mapping populations to evaluate genetic diversity for disease resistance.
Seed increases were conducted for 100 accessions with low seed quantities, which include 12 wild relatives. For the 1,220 accessions comprising the Zimbabwe collection, phenotypic data was collected on plant height, panicle length, and exsertion of the panicle from the flag leaf. Additionally, three germplasm subsets representing accessions collected from specific regions of Zimbabwe, were evaluated for resistance to anthracnose. Segregating populations were developed to evaluate the genetics of host-plant resistance for anthracnose, leaf blight, and grain mold. The collection from Ghana was evaluated for acid soil tolerance. Stalk sweetness was evaluated for 920 sorghum accessions with approximately 500 identified as having a sweet stalk that could be used as breeding lines to develop improved cultivars for bio-energy production. Additionally, a subset of 22 sweet sorghum accessions were selected and evaluated for biomass production.
Ehiopian sorghum collection as a source of anthracnose resistance germplasm. Ethiopia is an important source of genetic diversity for sorghum improvement and may also provide new sources of genetic variation for anthracnose resistance by ARS researchers in Mayaguez, Puerto Rico. A subset of 180 accessions that flower under temperate environmental conditions typical of the US sorghum growing region was selected and evaluated under field conditions for anthracnose resistance by ARS researchers in Mayaguez, Puerto Rico. The two year study identified 35 accessions that showed no disease symptoms. The resistant germplasm would benefit sorghum improvement programs as the anthracnose pathogen is genetically variable and losses of host-plant resistance have occurred.
Erpelding, J.E. 2009. Anthracnose disease response for photoperiod-insensitive Ethiopian germplasm from the U.S. sorghum collection. World Journal of Agricultural Sciences. 5(6):707-713.
Prom, L.K., Erpelding, J.E. 2009. New sources of grain mold resistance among accessions from Sudan. Tropical and Subtropical Agroecosystems. 10:457-463.
Prom, L.K., Montes-Garcia, N., Erpelding, J.E., Perumal, R., Medina-Ocegueda, S. 2010. Response of sorghum accessions from Chad and Uganda to natural infection by the downy mildew pathogen, Peronosclerospora sorghi in Mexico and the USA. Journal of Plant Diseases and Protection. 117(1):2-8.
Wang, M.L., Zhu, C., Barkley, N.L., Chen, Z., Erpelding, J.E., Murray, S., Tesso, T., Pederson, G.A., Yu, J. 2009. Assessment of Genetic Diversity and Population Structure of Accessions in the US Sweet Sorthum Germplasm Collection. Theoretical and Applied Genetics. Online DOI 10.1007/S00122-009-1155-6 120:13-23.
Erpelding, J.E., Prom, L.K. 2009. Response to anthracnose infection for a subset of ethiopian sorghum germplasm. Journal of Agriculture of the University of Puerto Rico. 93(3-4):195-206.