Location: Plant Physiology and Genetics Research2009 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 breding 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-producers. Formerly 5347-21410-004-00D (5/08).
3. Progress Report
Lesquerella: The third year of field studies to determine heat units needed for optimum growth and development with relationship to seed yield and oil quality of lesquerella was completed. Homozygous populations with 0% linoleic, 0% linolenic, 0% lesquerolic + 85% oleic acids were developed. A population with seed oil contents over 35% was evaluated in the field. Methods were developed for stable genetic transformation of Lesquerella fendleri and Lesquerella pallida. Plants were transformed with a castor bean hydroxylase gene to establish proof of principle and also test whether expression of additional hydroxylase activity in seeds can raise the level of hydroxyl fatty acid in seed oil, similar to the high amounts of hydroxyl fatty acids observed in castor oil. First generation transgenic plants have been obtained, and studies are continuing to test for stability of the newly introduced trait in subsequent plant generations. Guayule: Transgenic guayule lines with Mendel Technology 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-transgenetic parent. Samples from herbicide tests completed in 2008 are being 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 was established based on preliminary analyses of these results which showed there are differences in the germplasm for cold tolerance in guayule germplasm at this location. The first year of 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. A study was initiated to determine if a ploidy analyzer could be used to accurately reflect ploidy levels in guayule germplasm. Methods were developed for accelerated solvent extraction of resin and rubber from guayule tissue. These methods, coupled with the development of more rapid and accurate procedures for measuring resin and rubber, increased the speed of germplasm evaluation in field and growth chamber studies of guayule. Other oilseeds: Selection nurseries were established for camelina and vernonia and improved germplasm identified for further evaluation and crossing.