Enza Zaden has identified a significant part of their lettuce assortment to be highly resistant to Fol:4. But what is fusarium, what is the timeline, and what are Enza Zaden's results? It is explained in the article below.
What is fusarium?
For the first time, discovered in 1955 and described in 1967 as a novel forma specialis, Fusarium oxysporum f. sp. lactucae (Fol) is the pathogen causing "Fusarium wilt," a disease affecting lettuce. Fusarium is one of the most common plant diseases of lettuce, which damages lettuce's roots through covered and open cultivation, resulting in significant yield loss or even complete crop failure.
Timeline and research
Race 1 was identified in 1967 in Japan and then in the USA, Iran, Taiwan, South America, and Europe. Japan also identified races 2 and 3 in 2001. Taiwan is the only country to report on them now.
In 2016 a new Fusarium oxysporum f. sp. lactucae race 4 was described. Fusarium's new race poses a severe threat to European growers and breeders, which is why harmonization was necessary.
ISF has proposed a new differential set to their Disease Resistance Terminology Working Group (DRT WG) to differentiate this new race.
Using this harmonized protocol, Enza Zaden has identified a significant part of our Lettuce assortment to be High Resistant to Fol:4.
Enza Zaden's results
The interpretation rule is to have 3 levels of resistance: susceptible, intermediate resistance, and high resistance.
Reference isolates for Fusarium oxysporum f. sp. Fusarium oxysporum f. sp. lactucae race 4: After testing several isolates by all breeding companies active with lettuce, the isolate collected in the Netherlands and published by Gilardi et al., 2017 (a new race of Fusarium oxysporum f. sp. lactucae of lettuce. Plant Pathol. 66, 677-688. Doi: 10.1111/ppa.12616) was chosen as a reference isolate.
Reference controls:
Gisela was selected as a susceptible reference control.
Ballerina was selected as a lower level of intermediate resistant control.
Patriot was selected as a higher level of intermediate resistant control
Lomeria and Palmos were selected as resistant controls.
Read the updated differential set for Fusarium in Lettuce from ISF.
Please get in touch with your local sales representative for more information about their varieties and their resistances.
Enza Zaden
info@enzazaden.com
www.enzazaden.com