|DA SILVA, JORGE|
|Richard Jr, Edward|
Submitted to: American Society of Sugar Cane Technologists
Publication Type: Abstract Only
Publication Acceptance Date: 5/27/2006
Publication Date: 6/20/2006
Citation: Da Silva, J.A., Veremis, J.C., Solis-Gracia, N., Richard Jr, E.P. 2006. Toward breeding for biomass: tagging wild positive alleles [abstract]. Journal of the American Society of Sugar Cane Technologists. 26:121.
Technical Abstract: As bioconversion technologies improve, the potential of utilizing dedicated biomass crops, such as sugarcane for bio-energy also increases. Sugarcane has long been recognized as the most efficient crop on the planet in terms of converting solar energy into biomass, but its susceptibility to drought and cold presently limits its cultivation to tropical and subtropical regions. In addition, limited genetic gains obtained from breeding for sugar content in different breeding programs worldwide, suggest that a plateau has been reached for this trait. One way to overcome this obstacle would be to identify and introduce into commercial germplasm, alternative alleles controlling important traits, such as sugar metabolism and stress tolerance, present in other species of the “Saccharum complex,” that could increase the synthesis of sucrose in non-optimun environmental conditions. S. spontaneum has played an important role in the development of modern sugarcane varieties, but a limited number of clones from this species was used in the production of those varieties. The introgression of positive alleles through traditional methods, however, would be expensive and lengthy, due to “genetic drag”. In this scenario, molecular markers associated with traits of interest, allowing a more efficient selection to increase genetic gains, would be extremely valuable to sugarcane breeders. We used the DNA sequence information of genes involved in sucrose metabolism, recently deposited in the Genebank, as a result of the Brazilian Sugarcane Expressed Sequence Tag project – SUCEST, to develop Target Region Amplified Polymorphism – TRAP - markers. These markers are currently being applied to: 1) a collection of 51 S. spontaneum, that has been characterized and showed a significant amount of variation for sugar and cane yield components and 2) Miscanthus x sugarcane hybrids. Polymorphisms detected in these genomic regions are candidate markers for gene tagging of sucrose and fiber content (1), and cold and drought tolerance (2), to be used in marker-assisted selection for the introgression of superior alleles.