Location: Tropical Crops and Germplasm Research2011 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.
3. Progress Report
During fiscal year 2010, progress was made in the evaluation, characterization and identification of new sources of resistance among sorghum accessions from Africa. A total of 200 accessions from Burundi and Bostwana were morphologically characterized with 40 phenotype traits and screened for anthracnose and grain mold resistance. Collection site information and resistance evaluations were employed to identify ecogeographic regions with high frequency of resistance genotypes. In addition, 247 accessions from the non-quarantine Zimbabwe collection were evaluated at Isabela, PR, and digital images of representative panicles for each accession were taken and uploaded to the Germplasm Resources Information Network (GRIN) database. Subsequently, 68 accessions from this collection were selected for anthracnose and grain mold resistance assessment. The first replicated trial of this sub-set was completed, while the second is currently in progress. Grain mold is one of the most intractable biotic constrains to sorghum improvement, production and utilization worldwide. To increase the sources of resistance, 160 accessions from Ethiopia, Burkina Farso and South Africa that flower under temperate environmental conditions, typical of the U.S. sorghum growing region, were chosen for grain mold resistance assessment. The first year of a replicated trial has been conducted at Isabela, PR, employing high humidity conditions and artificial inoculation with specific pathotypes isolated from this location. Simultaneously, these accessions are been characterized for important phenotypic traits.