Submitted to: HortScience
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/21/2002
Publication Date: 1/20/2003
Citation: Farnham, M.W., Harrison Jr, H.F. 2003. Using self-compatible inbreds of broccoli as seed producers. Hortscience. 38:85-87.
Interpretive Summary: Broccoli has received increasing attention in recent years because it contains relatively high levels of the compounds glucoraphanin and sulforaphane that may provide protection against certain cancers in humans when it is consumed. The discovery that broccoli sprouts have 10 to 100 times more glucoraphanin than the mature vegetable head has stimulated commercial interest in broccoli seed and sprouts as new food products. As consequence, seed suppliers have experienced unprecedented demand for broccoli seed. We have tested varieties of broccoli developed by the ARS broccoli breeding program to determine if some of these lines could serve as better sources of relatively cheap and uniform broccoli seed than existing sources presently available. Normally, broccoli needs the help of bees to make cross-pollinations in a field in order to get good seed production; however, our evaluations in greenhouse and outdoor cages have identified several unique broccoli varieties that produce large amounts of uniform seed without the aid of insect pollinators. Some of these varieties produced high yields in all of the environments in which they were tested and these individuals are good candidates for testing in field studies. This research will lead to the release of a broccoli variety that produces a consistently high yield of seed, containing high levels of glucoraphanin. Such a variety will be a valuable product for the new broccoli sprout industry.
Technical Abstract: The discovery that broccoli (Brassica oleracea L., Italica Group) sprouts contain high levels of sulforaphane, a constituent that may provide chemoprotection against certain carcinogens, has stimulated much interest in sprout production of this crop. Studies were undertaken to determine the potential for producing broccoli seed using self-compatible selections from mopen-pollinated (OP) populations or doubled-haploid (DH) programs. In all field and greenhouse trials, three OP selections and seven DH lines produced selfed seed, but seed weight per plant and number per plant varied significantly among the entries. In all environments there were individuals with relatively high (i.e., greater than 3 g/plant) production that were significantly different from low (i.e., less than 2 g/plant) producers. The relative productivity of some lines varied greatly between experiments, which indicates that seed production of particular genotypes is affected differently by environmental conditions. This indicates the importance of identifying lines that are high producers of selfed seed across different environments. Two OP cultivar-derived lines (USVL102 and USVL104) and two DH lines (USVL062 and USVL093) that consistently produced relatively high yields in greenhouse and screen cage trials are good candidates for evaluating seed production in field tests and as possible sources of seed for sprouting.