Table 1.

Isolates of the alder Phytophthora, P. cambivora, and P. fragariae and their comparative cytological and cultural properties

Species	Isolates	Chromosome no.,* inferred karyotype	Meiosis	Colony development	Oogonial type,†	Antheridial type‡	Optimum/maximum growth temperatures, °C
Alder Phytophthora
Standard form	P669¶, P670¶‖, P671‖, P766‖, P772¶ (U.K.); P817¶, P818§¶ (Germany); P834¶‖, P846¶ (France); P844,¶‖, P883, P884 (Austria)	18–22, ≈4n + 2	Incomplete	Unstable	Ornamented	2A	≈25/30
German variant	P889¶‖, P890¶‖	16–18, ≈2n + 7	Incomplete	Unstable	Ornamented	2A	≈27/32
Dutch variant	P770¶‖	13–15, ≈2n + 4	Complete	Very unstable	Extremely ornamented	1A + P	≈27/32
Swedish variant	P875¶‖, P876¶‖, P887¶, P888¶	11–13, ≈2n + 2	Complete	Very unstable	Smooth	2A	≈27/30
U.K. variant	P841¶‖	§
P. cambivora**	P199¶‖, P208‖, P819‖, P820‖ (U.K.); P821‖ (Italy)	10–12, 2n	Complete	Stable	Ornamented	2A	≈27/34
P. fragariae**
Var. fragariae	P964¶, P965¶ (U.K.)	10–12, 2n	Complete	Stable	Smooth	1A + P	≈25/30
Var. rubi	P822‖ (France); P823‖ (U.K.)

^*A range limit normally is given for Phytophthora chromosome numbers. 

^†Smooth-walled, see Fig. 1d; ornamented, Fig. 1e; extremely ornamented, Fig. 1 f and h. 

^‡2A, large, two-celled amphigynous antheridia; 1A + P, predominantly small, single-celled amphigynous plus some paragynous antheridia. 

^§U.K. variant P841 was too unstable to tabulate; see text. 

^¶Isolate examined by ITS sequence or by ITS digestion. 

^‖Isolate examined cytologically. 

^**In a separate study, a further 20 isolates of P. cambivora and >40 isolates of the two varieties of P. fragariae, respectively, were subjected to ITS digestion; in each case they exhibited the same digest patterns as the isolates of these species listed here.