Principles of Plant Genetics and Breeding

396 CHAPTER 21
determining and assessing gene function in silico: the complexity arising from genes interacting with each other and their
environments (both natural and managed) requires a mechanism to assimilate the many and varied combinations. Simulation
modeling provides such a mechanism.
A blue future
As a result of this research, we will know the identity and function of the different genes involved in stay-green, enabling sorghum
breeders to develop a new generation of crops adapted to our increasingly water-scarce world. Ultimately, we hope to transfer
the stay-green genes to grain crops less well adapted to dry environments (i.e., rice, wheat, maize), or to identify similar droughtresistant
mechanisms in those crops. The global conservation of gene order among sorghum, rice, and other grass species is
clear from RFLP mapping information (Wilson et al. 1999). Utilizing stay-green genes in rice could revolutionize rain-fed rice
production.
The 1960s and 1970s were dominated by the “Green Revolution”, when semidwarf varieties of wheat and rice were grown
with high water and nitrogen inputs to produce record yields of grain. The early 21st century needs to be dominated by a “Blue
Revolution” in which genetic, agronomic, and management solutions are integrated to ensure food security in the face of global
water shortages.
Acknowledgments
The Grains Research and Development Corporation and the Queensland Department of Primary Industries and Fisheries funded
the Australian aspects of this research. Components of this research undertaken in the United States were funded by the National
Science Foundation.
References
Borrell A.K., G.L. Hammer, and E. Van Oosterom. 2001. Stay-green: A consequence of the balance between supply and demand
for nitrogen during grain filling? Ann. Appl. Biol. 138:91–95.
Borrell, A.K., E. Van Oosterom, G. Hammer, D. Jordan, and A. Douglas. 2003. Proceedings of the Australian Agronomy
Conference. Australian Society of Agronomy, Gosford, Australia.
Chapman, S.C., M. Cooper, D. Podlich, and G.L. Hammer. 2003. Evaluating plant breeding strategies by simulating gene action
and dryland environment effects. Agron. J. 95:99–113.
Downer, A. 2000. Sustenance and security: Australia’s multi-layered approach. In: Proceedings of a conference on food, water
and war: Security in a world of conflict. Crawford Fund for International Agricultural Research, Parliament House, Canberra,
15 August 2000. ACIAR Monograph No. 73, pp. 9–15.
Dupont, A. 2000. Food, water and security: What are the connections? In: Proceedings of a conference on food, water and war:
Security in a world of conflict. Crawford Fund for International Agricultural Research, Parliament House, Canberra, 15 August
2000. ACIAR Monograph No. 73, pp. 39–59.
Hammer, G.L. 1998. Crop modelling: Current status and opportunities to advance. Acta Horticulturae 456:27–36.
Hammer, G., M.J. Kropff, T.R. Sinclair, and J.R. Porter. 2002. Future contributions of crop modelling – from heuristics and supporting
decision-making to understanding genetic regulation and aiding crop improvement. Eur. J. Agron. 18:15–31.
Holzberg, S., P. Brosio, C. Gross, and G.P. Pogue. 2002. Barley stripe mosaic virus-induced gene silencing in a monocot plant.
Plant J. 30:315–327.
Klein, P.E., R.R. Klein, J. Vrebalov, and J.E. Mullet. 2003. Sequence-based alignment of sorghum chromosome 3 and rice
chromosome 1 reveals extensive conservation of gene order and one major chromosomal rearrangement. Plant J. 34:605–621.
Klein, R.R., P.E. Klein, A.K. Chhabra, et al. 2001. Molecular mapping of the rf1 gene for pollen fertility restoration in sorghum
(Sorghum bicolor L.). Theor. Appl. Genet. 102:1206–1212.
Menz, M.A., R.R. Klein, J.E. Mullet, J.A. Obert, N.C. Unruh, and P.E. Klein. 2002. A high-density genetic map of Sorghum bicolor
(L.) Moench based on 2926 AFLP®, RFLP and SSR markers. Plant Mol. Biol. 48:483–499.
Miller, F. 1996. Sorghum. In: Lost crops of Africa, Vol. I. Grains (National Academy of Sciences, ed.), pp. 127–143. National
Academy Press, Washington, DC.
Mullet, J.E., R.R. Klein, and P.E. Klein. 2001. Sorghum bicolor – an important species for comparative grass genomics and a
source of beneficial genes for agriculture. Curr. Opinion Plant Biol. 5:118–121.
Tanksley, S.D., M.W. Ganal, and G.B. Martin. 1995. Chromosome landing: A paradigm for map-based gene cloning in plants
with large genomes. Trends Genet. 11:63–68.
Wilson, A.W., S.E. Harrington, W.L. Woodman, M. Lee, M.E. Sorrells, and S.R. McCouch 1999. Inferences on the genome
structure of progenitor maize through comparative analysis of rice, maize and the domesticated panicoids. Genetics
153:453–473.