Abstract
Abstract The golden potato cyst nematode, (GN), Globodera rostochiensis, is a major quarantine pest of potato. This study investigated the resistance of domestic and foreign potato varieties and breeding lines widely cultivated in Kazakhstan to GN. This was the first time that domestic varieties were evaluated using molecular and phenotypic methods. The Miras variety and the breeding lines KС-26, KС-24 and KС-37 were found to be the most valuable in terms of resistance, as was the Chinese variety Xisen 6 zoned in Kazakhstan. Foreign varieties Juwel, Secura, Colomba, Queen Anne, Lisana, Sanjava and Paroli also showed resistance to the pest. These genotypes represent a valuable source material for the breeding of potato varieties, resistant to G. rostochiensis. The 57R molecular marker provided 91% diagnostic accuracy, with no false-positives and only 9% false-negative. The calculation of the Fechner sign correlation coefficient showed a strong positive correlation between phenotypic resistance and the 57R marker detection, confirming its high diagnostic value and suitability for marker-assisted selection.