Location: Crop Protection and Management ResearchTitle: Molecular markers, genetic maps, and QTLs for peanut molecular breeding in peanut) Author
Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: 6/1/2013
Publication Date: 5/5/2014
Citation: Pandey, M.K., Guo, B., Holbrook Jr, C.C., Zhang, X., Bertioli, D.J., Isobe, S., Liang, X., Varshney, R.K. 2014. Molecular markers, genetic maps, and QTLs for peanut molecular breeding. In: Mallikarjuna, N., Varshney, R., editors. Genetics, Genomics and Breeding of Peanuts. Boca Raton, FL: CRC Press. p.79-113. Interpretive Summary: Peanut or groundnut, with current annual production of 38 million tons from an area of 24 million hectares, is the fourth-largest oilseed crop in the world and is mostly grown by resource-limited farmers of the semi-arid regions with relatively low inputs of chemical fertilizers. In spite of the potential of molecular markers in crop improvement, peanut experienced slow progress in the area of developing genomic resources such as molecular markers and genetic maps until 2005. Since then significant progress has been achieved as a result of concerted efforts of the international peanut community resulting in the development of > 6000 markers, several genetic maps, dense consensus genetic maps, and molecular breeding for resistance or tolerance to biotic stresses for peanut improvement. The progress made in genomic resources such as molecular markers, genetic maps, and marker-assisted breeding in peanut has started to make progress with the help of genomic resources and should help to overcome genetic bottlenecks, and result in accelerated breeding progress. Ongoing efforts should lead to the availability of the whole genome sequence in the near future, providing huge genomic resources which will hasten the much needed linking of phenotype with markers/genome sequences.
Technical Abstract: Integration of plant breeding, genetics and genomics promises to foster genetic enhancement leading to increased productivity, oil quality and resistance/tolerance to biotic and abiotic stresses. Recent advances have resulted in the development of genomic resources such as SSR markers, and genetic maps for diploids and tetraploids. Even though the tetraploid species has both the genomes, the genetic diversity observed in cultivated maps has been low. Therefore, only partial (<100 loci) to low-moderate (<300 loci) genetic maps could be constructed. Consensus genetic map were, therefore, constructed with 3,693 marker loci using mapping information of multiple mapping populations in order to integrate as many markers as possible on a single genetic map. Development of SNP markers should lead to even more dense genetic maps and use of these markers in routine breeding and genetic applications. Efforts with the available limited genomic resources led to the identification of linked markers for drought tolerance, oil quality and disease resistance in cultivated peanut through trait mapping. These developments also led to deployment of linked markers to improve disease resistance and oil quality. Ongoing efforts should lead to the availability of the whole genome sequence in the near future, providing huge genomic resources which will hasten the much needed linking of phenotype with markers/genome sequences. However, this can only be achieved with precise and high-throughput phenotyping for complex traits. Recent advances in peanut genomics and molecular breeding efforts provide hope for efficient genetic enhancement of cultivated peanut for production as well as quality constraints.