|Williams, Paul - UNIVERSITY OF WISCONSIN|
Submitted to: HortScience
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 14, 1997
Publication Date: N/A
Interpretive Summary: Brassica rapa and Brassica juncea are two species of crucifer plants containing numerous kinds of popular vegetables originating and cultivated throughout the orient. Brassica rapa includes Chinese cabbage, napa cabbage, bok choy, and turnip among other vegetable types. A related species, Brassica juncea, includes the commonly grown mustard greens. These vegetables are threatened by diseases that can potentially cause widespread damage. Commercial cultivars from these plant species were tested for their resistance to two common crucifer diseases, fusarium yellows and turnip mosaic virus. Resistance to the fusarium yellows, caused by a soil-born fungus, was found to be quite widespread. Resistance to turnip mosaic virus, on the other hand, was relatively rare. Sources of virus resistance in other oriental crucifers not tested in this study will have to be utilized for breeding virus resistant cultivars of these vegetables.
Technical Abstract: Thirty-seven Brassica rapa L. and B. juncea L. vegetable lines from nine different subspecies were tested for their disease reaction to two pathotypes of Fusarium yellows (Fusarium oxysporum Schlecht. f. sp. conglutinans (Wr.) Snyd. & Hans. race 1 and F. o. f. sp. raphani Kend. & Snyd. A subset of 16 vegetable lines from these same vegetable types were tested for their disease reaction to four strains of turnip mosaic virus (TuMV-C1, C2, C3, and C4). Resistance to both Fusarium pathotypes was widespread in these vegetable subspecies, whereas, resistance to any strain of TuMV was uncommon. The broad availability of resistance to Fusarium yellows and scarcity of resistance to TuMV necessitate different approaches to obtain disease resistant cultivars.