Marker-assisted selection: new tools and strategies

Feasibilty of zein proteins, simple sequence repeats and phenotypic traits for background selection in quality protein maize breeding

“…Moreover, any backcross progeny will deviate from the expected phenotypes due to recombination and/or linkage between the target genes from the donor parents and nearby genes (Ribaut and Hoisington, 1998). Such linkage drag could be minimised through line conversion, albeit, breeders do not have any direct control over the size or recombination break points (Semagn et al, 2006).…”

Can genomics boost productivity of orphan crops?

“…One of the first applications of genomics-assisted breeding has been the introgression of loci for resistance to biotic stresses or major quantitative trait loci (QTLs) for tolerance to abiotic stresses into elite genotypes through marker-assisted backcrossing (MABC) 4 . For instance, introgression of a major QTL for submergence tolerance (Sub1) into widely grown rice varieties has substantially improved yield in >15 million hectares of rain-fed low-land rice in South and Southeast Asia 5 .…”

“…Although several success stories have been published, mainly based on the MABC approach 4 , the overall impact of genomicsassisted breeding on crop development programs in developing countries remains very limited 6,7 , especially for complex traits. In the short term, the adoption and successful application of this approach outside of developed countries requires the following: first, scientists trained in modern breeding technologies; second, improved local infrastructure capacity for accurate and relevant phenotyping; third, local access to marker technologies for efficient genotyping; and fourth, the deployment of suitable datamanagement systems (Box 1).…”

“…Molecular markers associated with the QTL are used for screening the backcross populations for identification of the superior lines that possess the favorable QTL allele at each cycle of backcrossing. Depending on the population size and considering one or two target loci, two to three backcrosses are usually sufficient for recovering most of the recipient genome 4 . Progress can be monitored with the help of randomly selected molecular markers for monitoring the background selection.…”

A multiplex PCR system for detection of wide compatibility allele S5-n and erect panicle allele dep1 in rice

“…The technique has many advantages, such as its insensitivity to environmental conditions, high reliability, and time-efficiency (Dudley et al 1993, Ribaut et al 1998, Schuster 2011, Xu 2013. A functional marker is designed according to polymorphic sites within gene sequences affecting phenotypic variation (Andersen and Lübberstedt et al 2003).…”