Assessing resistance of promising potato cultivars to cyst-forming nematodes and wart
Abstract
Background. Potato cyst-forming nematodes and wart are quarantine pathogens and cause significant economic damage (harvest losses can reach 100%). Compared to fungicides, host resistance is one of the most eco-friendly, cost-effective, sustainable, and consumer-oriented (chemical-free produce) options. Since the phenotypic assessment of resistance is laborious and costly, a promising breeding trend is the use of DNA markers linked to R -genes, which make it possible to identify valuable genotypes at the early stages of the breeding process. Materials and methods. The material of the study included 5 cultivars, 8 promising precultivars, and 14 hybrids developed by the Udmurt Federal Research Center of the Ural Branch of the Russian Academy of Sciences cooperatively with leading breeding centers in Russia. The molecular genetic analysis employed 5 DNA markers of nematode and wart resistance genes, most often used in breeding programs. Results. A majority of genotypes (88.9%) had a marker linked to the wart resistance gene ( Sen1 ). Among the markers of resistance to the golden potato nematode, 57R and N195 (74.1 and 70.4%, respectively) were much more common than Gro1-4 (22.2%). The presence of the Gpa2 gene for potato nematode resistance was observed in 12 cultivars out of 27 (44.4% of the studied set). The results of genotyping were compared with the levels of susceptibility to Globodera rostochiensis and Synchytrium endobioticum in a number of cultivars. Diagnostic effectiveness of both H1 gene markers (57R and N195) in this set was 100%, the NL25 marker showed 86.7%, and the DNA marker Gro1-4 manifested the lowest efficiency, only 27.6%. Cases with false positive and false negative results were identified. Conclusion. The data obtained in this study attest to the expediency of using markers of the H1 (57R and N195) and Sen1 (NL25) genes in breeding programs, while markers of the Gro1-4 gene (Gro1-4) proved inefficient.