Potato cyst-forming nematode (PCN) Globodera rostochiensis Woll. is one of the harmful plant parasite which leads to a significant reduction in potato productivity and loss in yield quality. In Republic of Karelia PCN has been widely spreading (from 62° to 67° n.l.) for 35 years (Gruzdeva, Matveeva, 2010). PCN is endoparasite of the potato root system and almost absolutely depends on plant-host to finish life-cycle (hatching and penetration of invasive juveniles into the roots). Besides that the physiological state of plant-host in preinfestated phase plays an important role in an establishment of host-parasite relationships. The aim of the study was to investigate potato plant responses to short-term low temperature drop combined with low and high levels of PCN infestation. Responses were estimated as formation of plant cold resistance and resistance to PCN. Experiments were conducted in the growth chambers. Before infestation by PCN (10 and 50 cysts per plant) potato plants (cv. Nevsky) were growing for 6 days under the short-term temperature drop from +23° to +5°C for 2 h at the end of night (DROP treatment) and at +23°C (control). Plant cold resistance was estimated by LT50 method (Drozdov et al., 1976) and difference between temperatures that caused death in treated and control plant cells was accepted as plant cold resistance increment. Results have shown that independently of the dose plant infestation by PCN after DROP-treatment led to an increment in plant cold resistance compared with healthy drop-treated plants, which remained at higher level for three weeks. Nematode population in infested plants was much lower (2–3-folds) than in healthy plants under the both infestation levels. Thus, increment in plant cold resistance was accompanied by the rising in resistance to PCN.
Research was supported by the Russian Ministry of Education (№ P 1299).