Burgonya-fajtajelöltek fitoftóra (Phytophthora infestans) ellenállóságának vizsgálata provokációs kísérletben, 2022

Abstract

Potato late blight caused by Phytophthora infestans is the most devastating disease worldwide. Blight-resistant cultivars may potentially play an important role in the IPM of potatoes. In Hungary, the official VCU (Value for Cultivation and Use) trials aiming the variety registration are carried out by the National Food Chain Safety Office (Nébih) including resistance tests against the major potato diseases. This paper provides the latest results on the foliar resistance of potato candidate varieties to late blight agent. In 2022 four domestic candidate varieties (Red River, Hunor, Balatoni sárga, Golden River), two registered cultivars (Désirée, Agria), and two check cultivars (the highly susceptible Cleopatra and the resistant White Lady) were assessed using a whole-plant inoculation technique under walk-in plastic tunnel, in a microplot trial with two replications. As an inoculum, a Polish P. infestans isolate (MP 1548) with complex race character (1.3.4.6.7.8.10.11) was applied spraying a suspension of 20-25.000 sporangia/ml on the foliage of genotypes at the 12-14-leaf stage. Disease severity was tested on a 1-10 scale of increasing susceptibility estimating the infected leaf area compared with the entire foliage surface (infected leaf area %). Of the genotypes tested Balatoni sárga and Golden River candidate varieties proved to be resistant showing hypersensitive reaction (HR) and no lesions while infection rate of the highly susceptible check cv Cleopatra was 65 % producing intensive sporulation. Candidate variety Red River performed as a mid-susceptible genotype (inf.rate: 22,5%). Additionally, infection rate of the genotypes Désirée, Agria and Hunor were 32,5, 35,0 and 42,5 %, respectively rendering them susceptible varieties. Based on the 2009/128 EK directive aiming a 50 % reduction of pesticide use by 2030, the above-mentioned resistant cultivars, in case of registration, may play an important role in the IPM of potato.