Evaluating resistance of potato cultivars and breeding clones to golden cyst nematode Globodera rostochiensis in China

The golden cyst nematode, Globodera rostochiensis, is a regulatory pathogen that can significantly reduce potato yields and hinder the international trade of potatoes. Unfortunately, this nematode has been reported in southwestern China. Nevertheless, limited information exists on the resistance levels of Chinese potato germplasm, especially primary commercial cultivars, to G. rostochiensis in southwestern China. This study evaluated the resistance of 35 potato cultivars currently grown in the southwest and northern China, along with 132 novel breeding clones, to G. rostochiensis. Our result showed that 8 cultivars and 35 clones were identified as carrying the H1 resistance gene using two established molecular markers, 57R and TG689, including the prominent cultivars ‘Atlantic’ and ‘Jizhangshu 12’, which rank among the top five in terms of cultivated area in China. Furthermore, two cultivars, ‘Yunshu 202’ and ‘Zhongshu 20’, along with 13 clones, demonstrated high resistance to G. rostochiensis, with no cysts detected in the rhizosphere soil through bioassays. The resistant cultivar ‘Yunshu 202’ stimulated G. rostochiensis hatching, yet the invading J2s failed to progress into the female stage. The results highlight the potential for developing resistant cultivars to reduce potato cyst nematode population densities for future research endeavors. This study identified resistant cultivars for immediate integration into China's comprehensive potato cyst nematode management strategy, while also facilitating the screening of breeding clones for resistance to G. rostochiensis.