Progress towards a Universal Linkage Map In Tetraploid Highbush Blueberry
Progress towards a Universal Linkage Map In Tetraploid Highbush Blueberry
Monday, September 26, 2011: 1:30 PM
Kohala 3
Despite great strides in highbush blueberry cultivar development since its recent domestication, genomic resources are scarce. A limited number of microsatellite markers exist. Only 5305 nucleotide sequences are available in GenBank, and there is no publically available linkage map. One of the objectives of a 2008-funded Specialty Crop Research Initiative project is to develop genomic tools for molecular breeding in the domesticated species of blueberry. Development of a well-saturated universal genetic map is crucial for identifying markers that are linked to traits of economic importance and for enabling DNA-informed breeding. A mapping population from a cross between ‘Draper’ and ‘Jewel’ was propagated at Michigan State University and planted in five locations including Oregon, Michigan, Florida, Georgia and Scotland. This population is being evaluated for a number of important phenotypic traits and is expected to segregate for many. New markers derived from expressed sequence tags (ESTs) generated in this project include simple sequence repeats (SSR) and EST-PCR, and are being used to identify quantitative trait loci associated with cold hardiness, chilling requirement, and fruit quality traits. Data on > 100 markers were analyzed using TetraploidMap. These markers show segregation patterns consistent with the simplest model for meiosis involving random chromosomal segregation and allowing the production of a draft tetraploid blueberry linkage map. Once completed, this map and additional new markers will provide useful genetic tools for use in marker assisted breeding, thus accelerating the development of new high quality blueberry cultivars.