Syngenta Flowers has been breeding highly resistant varieties in several classes of traditional bedding plants with the launch of our XDR branded Cora ® vinca (resistant to over 30 strains of aerial Phytophthora) and Imara ® Impatiens walleriana (highly resistant to IDM) in 2019. To meet our internal standards, all XDR products must: 1) exhibit best-in-class performance under disease pressure; 2) endure rigorous testing in both field and lab settings around the globe; and 3) obtain independent verification from third-party experts. Breeding technologies in vegetables and agronomic crops have supplied a standard terminology set and knowledge base for how disease resistance is defined in agriculture. The Syngenta Group has long been a foremost breeding expert in disease resistance in many classes of food crops and we bring that strength to our Flowers business. It’s important to remember the difference between resistant and immune (see table on “Important resistance terminology”). For example, IDM infection on resistant genetics of I. walleriana may show sporulation of the pathogen with some minor leaf abscission, but you won’t see total defoliation. This means that the disease must still be prevented using the proper environmental and chemical controls. In 2019, a working group of horticulture and plant pathology leaders and academic specialists was created to ensure that everyone was aligned with parameters for claiming the various levels of disease resistance and consistent terminology was ultimately adopted for the floriculture industry.
Important Resistance Terminology
Immunity: When a plant isn’t subject to attack or infection by a specified pest High Resistance: Plant varieties that highly restrict the growth and/or development of the specified pest and/or the damage it causes under normal pest pressure when compared to susceptible varieties. These plant varieties may, however, exhibit some symptoms or damage under heavy pest pressure. Varieties claiming the same level of resistance against a specific pest may exhibit a different resistance response due to a different genetic makeup of a variety. Intermediate Resistance: Plant varieties that restrict the growth and/or development of the specified pest and/or the damage it causes but may exhibit a greater range of symptoms or damage compared to high resistant varieties.
Source: International Seeds Federation: Definition of the Terms Describing the Reaction of Plants to Pests for the Vegetable Seed Industry (Adopted by the ISF Vegetable and Ornamental Crops Section in May 2017)
Imara ® XDR Mix
Cora ® XDR Apricot
Cora ® XDR Vinca Series in Gilroy, CA Wk 33, 2021
Made with FlippingBook Learn more on our blog