Domestication to Crop Improvement: Genetic Resources for Sorghum and Saccharum (Andropogoneae)
Sally L. Dillon2,
Frances M. Shapter1,
Robert J. Henry1,*,
Liz Izquierdo1 and
L. Slade Lee1
1 Centre for Plant Conservation Genetics, Southern Cross University, PO Box 157, Lismore, NSW 2480, Australia
2 Australian Tropical Crops and Forages Centre, Queensland
Department of Primary Industries and Fisheries, Biloela, QLD 4715,
An open access article from Annals of Botany 2007 100(5):975-989.
Background: Both sorghum (Sorghum bicolor) and sugarcane (Saccharum officinarum)are members of the Andropogoneae tribe in the Poaceae and areeach other's closest relatives amongst cultivated plants. Bothare relatively recent domesticates and comparatively littleof the genetic potential of these taxa and their wild relativeshas been captured by breeding programmes to date. This reviewassesses the genetic gains made by plant breeders since domesticationand the progress in the characterization of genetic resourcesand their utilization in crop improvement for these two relatedspecies.
Genetic Resources: The genome of sorghum has recently been sequenced providinga great boost to our knowledge of the evolution of grass genomesand the wealth of diversity within S. bicolor taxa. Molecularanalysis of the Sorghum genus has identified close relativesof S. bicolor with novel traits, endosperm structure and compositionthat may be used to expand the cultivated gene pool. Mutantpopulations (including TILLING populations) provide a usefuladdition to genetic resources for this species. Sugarcane isa complex polyploid with a large and variable number of copiesof each gene. The wild relatives of sugarcane represent a reservoirof genetic diversity for use in sugarcane improvement. Techniquesfor quantitative molecular analysis of gene or allele copy numberin this genetically complex crop have been developed. SNP discoveryand mapping in sugarcane has been advanced by the developmentof high-throughput techniques for ecoTILLING in sugarcane. Geneticlinkage maps of the sugarcane genome are being improved foruse in breeding selection. The improvement of both sorghum andsugarcane will be accelerated by the incorporation of more diversegermplasm into the domesticated gene pools using molecular toolsand the improved knowledge of these genomes.
Genomics, sorghum, Sorghum bicolor, sugarcane, Saccharum officinarum, crop improvement, domestication