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United States Department of Agriculture

Agricultural Research Service

Research Project: Commercialization of New Industrial Crop Germplasm and Cropping Systems

Location: Plant Physiology and Genetics Research

2010 Annual Report


1a. Objectives (from AD-416)
Objective 1: Develop enhanced germplasm and cultivars for low input, high yielding, cost-competitive oilseed, latex, and biomass crops as bio-fuels and bio-based products. Objective 2: Determine the physiological, biochemical, and molecular factors limiting the growth and yield of oilseed, latex, and biomass crops that could be targeted for improvement in a conventiional and/or molecular breeding program. Objective 3: Develop economical production systems for new/alternative industrial crops.


1b. Approach (from AD-416)
Germplasm that has been previously collected as well as new germplasm collections will be evaluated for important characteristics to meet the objectives. Evaluation data and seed will be sent to the appropriate curators for entry into the National Plant Germplasm System. Standard and molecular breeding procedures will be used in selecting and improving germplasm to develop enhanced germplasm with increased levels of desired traits such as oil content, specific fatty acid profiles, latex and resin contents, yield, resistance to biotic and abiotic stresses, and biomass. Production systems will be devised and evaluated utilizing traditional plus new/alternative crops to develop systems that provide farmers profitable and sustainable management practices. New and improved analytical procedures will be developed as needed to evaluate germplasm for desired traits and potential co-products.


3. Progress Report
Lesquerella: The research geneticist leading the lesquerella breeding and agronomic portion of the CRIS transferred to the NCGRP at Fort Collins. However, research to meet milestones 1 and 2 above was continued in-house to develop plant populations with lesquerolic acid contents above 65%, oil contents above 35%, and a harvest index above 35. Yield trials evaluating this germplasm were conducted at two locations for a second year. Oil and fatty acid analyses are underway. A growers’ handbook for Arizona has been developed in cooperation with extension personnel at the University of Arizona. Efforts to develop stable transformation methods for Lesquerella to further improve oil and agronomic traits are ongoing. Guayule: Genetically modified germplasm lines were evaluated in the field for morphological traits and in the laboratory for rubber and resin contents. Preliminary analyses of the results do not indicate any significant increases in rubber, resin or biomass yield compared to the non-transformed control plants. Samples from herbicide tests completed in 2008 were evaluated for rubber and resin contents to determine if herbicides used in plant establishment affected rubber and resin yields. A three year field study was completed at Halfway, Texas to screen for cold tolerance in guayule germplasm. Samples were taken for biomass yield and rubber and resin concentration determination. A new test is planned for FY11 at Lubbock, Texas based on preliminary analyses of these results which showed there are differences in the germplasm for cold tolerance in guayule germplasm at this location. A study to determine the effects of month of harvest on guayule rubber, resin, and biomass yields and the subsequent regrowth of plants following harvest was conducted. Results indicate harvesting during the summer months is not recommended if regrowth of plants for subsequent harvests is a priority. A study was completed to develop a rapid method for evaluating ploidy levels in guayule and to evaluate ploidy levels in guayule germplasm obtained from the collection at USDA-ARS, Parlier, CA. The method was successful and indicated that only two diploid lines were in the germplasm collection. Additional germplasm screenings are underway of genetically modified populations and traditional breeding populations. Additional diploid plants needed for developing new germplasm have been identified in the traditional breeding population. Methods developed for accelerated solvent extraction of resin and rubber from guayule tissues were used to evaluate samples from herbicide tests and other agronomic studies. Other oilseeds: Selection nurseries were conducted for camelina and improved germplasm was identified for further evaluation.


4. Accomplishments


Review Publications
Coffelt, T.A., Nakayama, F.S. (2010). DETERMINING OPTIMUM HARVEST TIME FOR GUAYULE LATEX AND BIOMASS. Industrial Crops and Products, 31:131-133.

Coffelt, T.A., Nakayama, F.S., Ray, D.T., Cornish, K., McMahan, C.M. 2009. Post-harvest storage effects on guayule latex and rubber yields. Industrial Crops and Products. 29(2-3):326-335.

Holt, G.A., Coffelt, T.A., Chow, P., Nakayama, F. 2009. Biobased composition boards made from cotton gin and guayule waste: Select physical and mechanical properties. International Journal of Materials and Product Technology. 36(1/2/3/4):104-114.

Coffelt, T.A., Nakayama, F.S., Ray, D.T., Cornish, K., Mcmahan, C.M., Williams, C.F. 2009. Plant Population, Planting Date, and Germplasm Effects on Guayule Latex, Rubber and Resin Yields. Industrial Crops and Products. 29(1):255-260.

Slocombe, S.P., Cornah, J., Pinfield-Wells, H., Soady, K., Zhang, Q.Y., Gilday, A., Dyer, J.M., Graham, I.A. (2009). Oil accumulation in leaves directed by modification of fatty acid breakdown and lipid synthesis pathways. Plant Biotechnology Journal,7:694-703.

Gidda, S.K., Shockey, J.M., Rothstein, S.J., Dyer, J.M., Mullen, R.T. 2009. Arabidopsis thaliana GPAT8 and GPAT9 are localized to the ER and possess distinct ER retrieval signals: Functional divergence of the dilysine ER retrieval motif in plant cells. Plant Physiology and Biochemistry. 47(10):867-879.

Williams, C.F., Coffelt, T.A., Watson, J.E. 2009. Increased soil sorption of pendimethalin due to deposition of guayule-derived detritus. Soil Science Society of America Journal. 73(6):1952-1957.

Ray, D.T., Foster, M.A., Coffelt, T.A., Mcmahan, C.M. Guayule: Culture, Breeding and Rubber Production, Industrial Crops and Uses (2010), pp. 384-410.

Bekaardt, C.R., Coffelt, T.A., Fenwick, J.R., Wiesner, L.E. Environmental, irrigation and fertilization impacts on the seed quality of guayule (Parthenium argentatum Gray). Industrial Crops and Products (2010), Vol. 31, Issue 3, pp. 427-436.

Last Modified: 10/17/2017
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