Submitted to: Germplasm Release
Publication Type: Germplasm Release
Publication Acceptance Date: September 18, 2009
Publication Date: N/A
Technical Abstract: The broccoli breeding program at the U.S. Vegetable Laboratory has developed a large number of doubled-haploid lines of broccoli using anther culture. Typically, the lines that result from these cultures are highly uniform and can be presumed to be highly homozygous. In relatively rare instances doubled-haploid lines exhibit variants that do not become evident until the first generation from seed. The most common variant observed is a plant with glossy leaf type. By selecting and selfing glossy leaf variants and nonglossy (normal) plants from the same line, it has been possible to develop paired lines that appear nearly identical except for the glossy leaf trait. DNA marker analysis has verified that the paired lines can be considered near-isogenic lines for the glossy leaf trait. In all cases observed to date, the glossy leaf trait appears to be controlled by a recessive gene although tests have not been conducted to determine if the glossy variants occur due to allelic changes at the same locus or different loci. Two pairs of near isogenic lines for glossy leaves are being released by ARS. One pair of lines is derived from a dihaploid regenerated from an anther culture of the commercial hybrid ‘Marathon’, and these lines are designated USVL115-GL and USVL115-NG. The other pair is derived from a dihaploid regenerated from an anther culture of a USVL F1 hybrid made by crossing a ‘Marathon’ derived doubled-haploid line with an ‘Everest’-derived doubled-haploid line; these lines are designated USVL188-GL and USVL188-NG. All four of the lines are partially self-compatible and will produce some seed without manual pollinations; however, to maximize seed production of these lines it is recommended to use self pollination techniques (e.g., bud pollinations) that are standard for producing Brassica seed. These two pairs of broccoli lines that are near-isogenic for leaf glossiness should prove useful tools for studying the effects of this leaf characteristic on insect behavior or predation as well as other things that might be impacted by this character associated with leaf waxiness.