Breeding vegetables for pest resistance
Cornell plant breeders are hard at work developing vegetables with natural resistance to common diseases and other pests. This year broccoli plants that have been bred selectively for five generations were inoculated four times with the fungus that causes blackrot, but they showed virtually no symptoms of the disease. Most of them developed into excellent plants. A new molecular marker associated with resistance to blackrot disease was discovered this year. This discovery may make selection of resistant plants more convenient in the future. Plans are under way to apply what has been learned from broccoli to cauliflower and cabbage.
New York potato growers have been plagued by new forms of the disease late blight. Only costly chemical management options are available to prevent crop loss. When the Cornell Plant Breeding Program potato clone "Q237-25" was evaluated for resistance to late blight in 1996, it ranked sixth among 26 potato clones. Its creators are confident that this clone will develop into seed with a reduced dependency on fungicides.
Not only is Q237-25 resistant to late blight, but it has good tuber shape and color and is resistant to a viral disease and to three races of microscopic roundworms called nematodes. (Some nematodes are biological control agents that feed on crop pests; others are pests that feed on crops.)
The 3,000 clones produced from Q237-25 in 1996 will be planted this summer in an effort to find a clone equal to or better than its parent.