Genomics of tropical maize, a staple food and feed across the world
Yunbi Xu
Genomics of tropical maize, a staple food and feed across the world - New York (USA) Springer : 2008 - p. 333-370
Tropical maize is a major staple crop providing food and feed across the developing world. Genomics of maize is very well advanced but heavily focused on temperate germplasm. Tropical maize germplasm is substantially more diverse than temperate maize with a wide range of landraces and types of varieties. Thus, diversity analysis at genetic, molecular, and functional levels is important for underpinning translational genomics from temperate to tropical maize. Virtually all types of markers have been used for molecular linkage mapping in maize over the past decade. However, single nucleotide polymorphic markers are now very well developed in maize and are becoming the marker of choice for most applications. Both linkage and association-based mapping has been used for identifying markertrait associations. Maize genome sequencing is now well advanced but focused on gene-rich regions due to its high density of repetitive elements. Functional genomics activities have made use of insertional mutation-based cloning as well as expressed sequence tags and map-based cloning. A wide range of genomic databases and tools have been developed, of which MaizeGDB features a wealth of data and resources facilitating the scientific study of maize. Genomics-assisted breeding is at an advanced stage in temperate, especially in private sector breeding programs, and applications in tropical maize are also common. Marker-assisted selection has been used in maize for yield, grain quality, abiotic and biotic stresses. Using these approaches, commercial maize breeding programs have reported twice the rate of genetic gain compared with phenotypic selection. However, reports in the literature from public breeding programs are inconsistent and generally less promising. Applied maize genomics in the tropics should in the future focus on tropical maize fingerprinting, haplotype establishment, allele mining, gene discovery, understanding genotype-byenvironment interactions, and development of decision support tools and networks for developing countries to facilitate effective applications of genomics in maize breeding.
English
Genomics of tropical maize, a staple food and feed across the world - New York (USA) Springer : 2008 - p. 333-370
Tropical maize is a major staple crop providing food and feed across the developing world. Genomics of maize is very well advanced but heavily focused on temperate germplasm. Tropical maize germplasm is substantially more diverse than temperate maize with a wide range of landraces and types of varieties. Thus, diversity analysis at genetic, molecular, and functional levels is important for underpinning translational genomics from temperate to tropical maize. Virtually all types of markers have been used for molecular linkage mapping in maize over the past decade. However, single nucleotide polymorphic markers are now very well developed in maize and are becoming the marker of choice for most applications. Both linkage and association-based mapping has been used for identifying markertrait associations. Maize genome sequencing is now well advanced but focused on gene-rich regions due to its high density of repetitive elements. Functional genomics activities have made use of insertional mutation-based cloning as well as expressed sequence tags and map-based cloning. A wide range of genomic databases and tools have been developed, of which MaizeGDB features a wealth of data and resources facilitating the scientific study of maize. Genomics-assisted breeding is at an advanced stage in temperate, especially in private sector breeding programs, and applications in tropical maize are also common. Marker-assisted selection has been used in maize for yield, grain quality, abiotic and biotic stresses. Using these approaches, commercial maize breeding programs have reported twice the rate of genetic gain compared with phenotypic selection. However, reports in the literature from public breeding programs are inconsistent and generally less promising. Applied maize genomics in the tropics should in the future focus on tropical maize fingerprinting, haplotype establishment, allele mining, gene discovery, understanding genotype-byenvironment interactions, and development of decision support tools and networks for developing countries to facilitate effective applications of genomics in maize breeding.
English