SBIR-STTR Award

Research will be conducted to refine methods for control of microspore development in wheat anthers toward increasing the proportion of microspores at stages most responsive to androgenesis induction. In Phase I, prior results indicating the existence of a signal (for androgenesis) control system response of wheat microspores will be extended, to refine and optimize treatments for increasing the yields of embryoids and green plants from anther cultures, while improving procedures for isolation and culture of microspores. Candidate signal compounds have been identified. Genotype differences in wheats for responsiveness to the induction signal will be studies. Methods will be developed also to isolate microspores cultured different periods after induction. Research aims to provide the foundation for in depth Phase II investigations into the biochemical genetic mechanism(s) controlling the switching of microspore development from its programmed pathway toward pollen to a developmental pathway leading to the formation of a pseudoembryo (embryoid) regenerable into a plant via the process of androgenesis.Applications:The development of an efficient, widely applicable wheat microspore culture technology is Applications:

Research proposed will lead to the development of technologies for increasing the efficiency of doubled haploidproduction in wheat and other cereals for accelerating practical breeding and genetics research. The increased androgenesis response to chemical treatments identified from Phase I studies will be further investigated both to improve the responses to the chemical treatment and to adapt the procedures to a wider range of wheat genotypes. Other research will refine methods for estimating microspore development stages and relate microspore development to signal responses which induce androgenesis. Cytological analyses will be used to monitor changes in microspore development in response to the chemicals applied. Technology for isolating and subdividing batches of pure microspores by their development stages will be further refined, and methods for in vitro culture of the purlfied microspores will be expanded to increase the yields of embryogenic calli and green plants regenerated from them. A new approach using less toxic chemicals than colchicine will be studied as a method for doubling the haploid microspores as they develop in culture. Biochemical investigations of the signal system for including androgenesis will be initiated to identify parameters and active components of the signal cascades induced in the microspores by the treatments.Applications:The development of efficient, widely applicable wheat microspore culture technologies can be achieved based on indications obtained in Phase I. The technologies should be widely applicable in wheat and other crop cultivar development programs, because of the acceleration of breeding and efficiency of selection possible with doubled haploid systems. The cost and time savings achieved in line or cultivar development can greatly impact the economics of commercial hybrid development, and permit far more efficient exploitation of plant genetic, human, and financial resources in such programs.