|Smith, J. Powell|
Submitted to: HortScience
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/12/2005
Publication Date: 10/14/2005
Citation: Farnham, M.W., Ruttencutter, G., Smith, J., Keinath, A.P. 2005. Hybridizing collard and cabbage may provide a means to develop collard cultivars. HortScience. 40:1686-1689.
Interpretive Summary: Collard is a very popular leafy green vegetable crop grown throughout the southeastern United States. When vegetable growers produce a crop of collard, there are only about seven or eight varieties that they can choose to grow. Most of these varieties are susceptible to some serious diseases that are prevalent in the region. If growers had some new resistant collard varieties at their disposal, they might grow them to protect future crops from disease outbreaks. With this in mind, we proposed a new method of developing collard cultivars that entails crossing collard with its close relative cabbage. Due to the fact that heading of collard is a recessive trait, we postulated that the cabbage-collard hybrids resulting from the crosses would look mostly like collard and might serve as new collard cultivars that would be available to producers. We made sixteen cabbage-collard hybrids and tested them in three separate field trials from 1999 through 2000, comparing them to existing collard varieties. In general, the appearance of a majority of the cabbage-collard hybrids was more collard-like than cabbage-like. At least two of the experimental hybrids appeared to hold promise as potential new cultivars. It appears that this method we have devised could be used successfully to make new collard cultivars. Assuming some of the disease resistance characteristics of cabbage will be expressed in the hybrids with collards, growers should be able to use them to produce a crop that stands up against a disease attack and will not need to be protected by any pesticides. Thus, vegetables produced from the cabbage-collard hybrids and subsequently bought by consumers should be nutritious and pesticide-free.
Technical Abstract: Collard (Brassica oleracea L. Acephala Group) is a leafy green vegetable adapted to the southeastern United States. Today, the number of commercially-available collard cultivars is limited, and the most popular ones are susceptible to diseases like fusarium yellows, something that numerous cultivars of cabbage (B. oleracea Capitata group) are resistant to. We postulated that hybrids of cabbage and collard would look more like collard because heading of cabbage is at least partially recessive to the nonheading nature of collard. We also postulated that cabbage-collard hybrids might be used directly as collard cultivars that express disease resistances from cabbage. To test these postulates, cytoplasmic male sterile cabbage inbreds were crossed to different male fertile collard inbreds using bees in cages and hybrid seed was produced. Resulting cabbage-collard hybrids were compared to conventional collard cultivars for traits including fresh weight, height, width, heading habit, and uniformity in three replicated field trials in South Carolina. In all trials, cabbage-collard hybrids exhibited similar size and weight more like conventional collard than cabbage, and throughout most of the growing season the collards remained nonheading. In addition, the cabbage-collard hybrids were much more uniform than open-pollinated (OP) collard cultivars. Among cabbage-collard hybrids there was significant variation with some hybrids appearing more collard-like than others. Results indicate that select cabbage-collard hybrids could out perform certain conventional collards and serve as potential new cultivars of this crop.