Table 1.

Characteristics (origin, mating type, race defined on Black’s differentials) of P. infestans isolates used in this study

Isolate	Year, place of origin	Mating type	Racea	Resistanceb
				cv Sárpo Mira	cv Maris Piper	cv Bzura	cv Tarpan
MP324	1997, Koszalin	A1	1.2.3.4.5.6.7.8.10.11	8.6 ± 0.6	3.0 ± 1.9	7.7 ± 0.8	1.3 ± 0.5
MP618	2005, Nowy Sącz	A2	1.2.3.4.(5).6.7.10.11	8.6 ± 0.8	3.4 ± 1.4	5.7 ± 0.5	2.3 ± 1.2
MP650	2005, Nysa	A2	1.2.3.4.5.(6).7.(8).10.11	8.4 ± 1.0	4.0 ± 1.0	6.5 ± 1.2	3.0 ± 0.9
MP1353	2011, Białuty	A2	1.2.3.4.5.6.7.8.10.11	5.8 ± 0.4	n.t.	2.8 ± 1.2	2.3 ± 0.8

n.t. not tested

^aRace nomenclature is based on ability to infect the Black’s differential potato set (potatoes carrying R1–R11 genes) (Black et al. 1953)

^bThe mean resistance of cv. Sárpo Mira (resistant parent), Maris Piper (susceptible parent) and two standard cultivars Bzura and Tarpan to each of the isolates is shown in 1–9 scale, where 9 is the most resistant ± standard deviation