Seed World

New Lettuce Breeding Lines Show Strong Resistance to Major Pests and Diseases

USDA-ARS study reveals advanced green leaf, red leaf and romaine lettuce varieties that combat leafminer, corky root, and downy mildew, offering a sustainable alternative to chemical interventions for farmers.

In a recent news release, the USDA-Agricultural Research Service (USDA-ARS) study announced the development of new breeding lines of green leaf, red leaf and romaine lettuce with resistance to leafminer, corky root and downy mildew. This advancement marks a step forward in sustainable agriculture, offering farmers options to combat common pests and diseases without relying heavily on chemical interventions.

The study detailed the selection and breeding processes used to develop these resistant varieties. The research aimed to address the need for lettuce cultivars that can withstand common agricultural challenges while maintaining high yield and quality. The new breeding lines exhibited resistance to three major threats to lettuce crops: Leafminer infestation, Corky Root (a soil-borne disease that affects the plant roots, severely impacting plant health and productivity), and Downy Mildew, a fungal disease that thrives in moist conditions and can devastate lettuce crops.

Limited seed samples are available from the corresponding author for distribution to all interested parties for research purposes, including the development and commercialization of new cultivars. Samples will also be deposited in the National Plant Germplasm System. It is requested that appropriate recognition be made if the breeding lines contribute to research or the development of new germplasm, breeding lines, or cultivars.

USDA-ARS research geneticist Beiquan Mou developed the lettuce breeding lines in Salinas, California. The damages and economic losses caused by the insect and diseases prompted Mou to seek genetic solutions for the problems. Leafminers are major insect pests of many important crops in the world including lettuce. Lettuce roots infected with the corky root disease develop yellow to brown lesions that later become longitudinal corky ridges and restrict the absorption of water and nutrients. Downy mildew is one of the most economically important diseases of cultivated lettuce worldwide.

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