Use of The BioMark™ HD System for Diversity Study and Marker-Assisted Backcrossing in Capsicum
Time: 4:25 PM
Byoung-Cheorl Kang
Department of Plant Science, Seoul National University, Seoul 151-921, The Republic of Korea
The Capsicum genus of the Solanaceae family is one of the most economically important vegetable crops because of the diverse uses of its member species as vegetables, spices, and ingredients. To facilitate marker-assisted breeding and analysis of genetic diversity of Capsicum spp, we utilized single nucleotide polymorphism (SNP) markers. Capsicum diversity is getting lower in modern cultivars because of the genetic erosion. Therefore, it has become a hot issue to conserve genetic diversity and exploitation of wild germplasm in Capsicum. Analysis of genetic diversity and population structure is the first step to make an efficient use of germplasm. Although there have been several attempts to construct core collections in Capsicum, most of these works were limited due to handling small number of samples, relying mainly on the characterization of morphological traits or focusing only C. annuum species. To expand understanding of the genetic diversity and population structure of germplasm in Capsicum, we used the BioMark™ HD System for genotyping a set of SNP markers. We analyzed about 4,500 accessions including cultivated species and wild species in Capsicum with 48 single nucleotide polymorphism (SNP) markers. Together with genotype and phenotype data, we selected core-collections of 250 Capsicum accessions. Backcrossing is an effective breeding method for introducing useful traits to an elite cultivar. Compared to conventional backcrossing, marker-assisted backcross (MAB) is extremely useful for recovery of a recurrent parent’s genetic background. To obtain background selection markers, a total of 412 SNP markers was screened between breeding lines. Of the 412 SNP markers, polymorphic SNP markers evenly distributed in pepper genome were selected. Plants carrying the donor gene were selected using foreground selection markers from a BC1F1 populations. Multiple SNP genotype analysis was done for the selected plants using the BioMark™ HD System. Using this breeding scheme, we were able to obtain breeding lines very similar to recurrent parents in two generations.