Location: Grain, Forage, and Bioenergy Research2008 Annual Report
1a. Objectives (from AD-416)
The long-term objectives of this project are the development of sorghum (Sorghum bicolor) germplasm lines with improved bioenergy, feed, and food value, and the elucidation of genetic, biochemical, and biological factors impacting these characters. Over the next five years, the following specific objectives will be addressed: 1) Identify and evaluate genes to improve sorghum for bioenergy, food, and feed traits, 2) Develop a better understanding of genes and fundamental mechanisms controlling cell wall formation and energy availability, and 3) Develop molecular and other technologies for monitoring sorghum fungal pathogens and determine the effects of sorghum genetic modification for bioenergy on pathogen populations.
1b. Approach (from AD-416)
The project utilizes a diverse set of technologies and approaches that are best delineated by objective: Objective 1 will be addressed primarily using traditional whole-plant plant breeding techniques, animal feeding trials, and established laboratory methods for assessment of feed and bioenergy value. Objective 2 will be addressed using current molecular and biochemistry technologies including PCR, RT-PCR, HPLC, microarrays, GC-MS. Objective 3 incorporates both field-based experiments and current molecular biology technologies. All experiments will utilize sound statistical designs to allow hypothesis testing at established levels of probability.
3. Progress Report
by CRIS Project Objectives: 1.a. Tissue samples of lines near-isogenic for bmr-6, bmr-12, and “stacked bmr-6+12” were sent to the W.S. Miner Institute for in compositional and situ diary feeding studies, and to USDA-ARS Peoria for fermentation studies. The 2nd year of a field-scale residue beef grazing study comparing isogenic wild type and bmr-12 grain hybrids is underway. An experiment comparing dairy performance when fed silage from wild-type and bmr-12 Atlas was completed, data analysis is pending. (NP301, Component 3) 1.b. New amylose-free (waxy) R-lines are undergoing their 2nd year of yield-trials. Crosses to verify fertility restoration reaction of new R- and B-line were made. Selected B-lines are being sterilized in A1 cytoplasm. Final selections of near-isogenic sister-lines pairs are being made in the field. Lines segregating for wxa and wxb alleles were identified and are being advanced. (NP301, Component 3) 1.c. Initial crosses of high starch content and high energy plant introduction lines with elite parents were accomplished using ms3 male sterility and selfing completed in winter greenhouse to recover male sterility expression. Back crosses are currently being made. (NP301, Component 3) 2.a. Identified the locus responsible for the bmr-6 phenotype, which contained a nonsense mutation in CAD80 gene. Expressed the CAD80 and CAD40 protein in E. coli and the enzymatic activity assay are being performed. Expressed BMR-12 (COMT) in E. coli and assays are pending. Plant tissue is being produce for a global gene expression study to be performed in collaboration with the National Genome Resource Center, Santa Fe, NM. (NP301, Component 3) 2.b. Four conserved non-coding sequences (CNS) in the CAD80 promoter shared with Brachypodium and Rice were identified. Conservation of CNS does not extend beyond the grasses. (NP301, Component 3) 3.a. Improved greenhouse assays were published. Field studies were expanded to Corpus Christi, TX to take advantage of higher pathogen pressure. (NP 303, Component 1) 3.b. Seed from low amylose (waxy) and wild-type lines has been collected. Lab screening to identify and isolate pathogens is scheduled to be initiated. (NP 303, Component 1) 3.c. Over 90 Fusarium spp. were isolated from grain and leaves of low lignin sorghum lines and wild-type counterparts. Sequencing of three genes from each fungal isolates has been completed. Greenhouse screens of low lignin sorghum lines inoculated with fungal sorghum isolates representing eight different species were conducted. (NP 303, Components 1, 3) 3.d Nearly 6000 antibiotic-producing bacteria were obtained from roots and soil of sorghum and wheat seedlings grown in field soil in growth chamber assays, and from roots and soil of field-grown sorghum. Biochemical and molecular genetic characterization of these isolates is complete. One growth chamber bioassay monitoring colonization of biocontrol bacterial isolates on sorghum roots and in soil was conducted. (NP 303, Component 4)
5. Significant Activities that Support Special Target Populations