01812nas a2200229 4500008004100000022001300041245008200054210006900136300001500205490000700220520111000227653002301337653001001360653003101370653001801401653001701419653001901436100001701455700001201472700001501484856008301499 1995 eng d a0032086200aAn unusual Phytophthora associated with widespread alder mortality in Britain0 aunusual Phytophthora associated with widespread alder mortality  a999 - 10070 v443 a

During 1993 and 1994 an unusual Phytophthora was consistently isolated from bark lesions at the stem bases of dying alder in Southern Britain. The Phytophthora resembles P. cambivora in both its gametangial and sporangial morphology. However, it is distinct from this species in being homothallic rather than outcrossing; in producing a significant proportion of small and sometimes partially developed oogonia; in having a high frequency of oosphere abortion; in having an appressed felty colony type with little or no aerial mycelium; and in exhibiting a lower optimum temperature for growth (c.22.5°C) and lower growth temperature maximum (c.29°C) on carrot agar than P. cambivora (c.27.5° and 33.5°C respectively). An inoculation test confirmed its pathogenicity to Alnus. The status of the alder Phytophthora is discussed. On the basis of its unusual characteristics and unusual host it is suggested that it might be a new or recently introduced organism rather than a previously unrecorded indigenous variant of P. cambivora.

10aAGRICULTURAL pests10aALDER10aALDER – Diseases & pests10aGREAT Britain10aPhytophthora10aPLANT diseases1 aBrasier, C M1 aRose, J1 aGibbs, J N uhttp://onlinelibrary.wiley.com/doi/10.1111/j.1365-3059.1995.tb02658.x/abstract