Lophodermium on pines, with special reference to species occurring on Pinus sylvestris in north-east Scotland

• Main Author: Minter, David William
• Published: University of Aberdeen 1977
• Subjects: 634.9
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.465798

This work is concerned with resolving contradictions found in previous research on Lophodermium pinastri (an ascomycete fungus inhabiting pine needles). The literature review shows how a number of species of Lophodermium on pine needles have been recognised and named, and how researchers have ignored largely these names and have used repeatedly the name L, pinastri regardless of the species involved, Not surprisingly therefore reports are contradictory and confused, some for example calling L,_ pinas tri a saprophyte, others a strong pathogen, A careful examination of the morphology of L" pinastri on secondary needles of Pinus sylvsstris in Scotland revealed that four distinct forms (A, B, C & P) can be recognised using characteristics of size, shape and colour. In particular, the depth to which asco'carps of each form are inserted in the host needle, and the character of the stromatic lines produced by each form are useful guides for identification. Form A produces many, and form D few black stromatic lines, while forms B & 0 produce few brown stromatic lines. Similarly, ascocarps of forms A. B & D are situated at least partly under the cuticle alone of the host, whereas ¦ascocarps of form C are totally subepidermal. Three of the forms we re recognised also on cones, and two on primary needles, though work on these was limited. Using samples from abroad and on many species of pine the morphology of the four forms was shown to be largely unaffected by variation of host anThis work is concerned with resolving contradictions found in previous research on Lophodermium pinastri (an ascomycete fungus inhabiting pine needles). The literature review shows how a number of species of Lophodermium on pine needles have been recognised and named, and how researchers have ignored largely these names and have used repeatedly the name L, pinastri regardless of the species involved, Not surprisingly therefore reports are contradictory and confused, some for example calling L,_ pinas tri a saprophyte, others a strong pathogen, A careful examination of the morphology of L" pinastri on secondary needles of Pinus sylvsstris in Scotland revealed that four distinct forms (A, B, C & P) can be recognised using characteristics of size, shape and colour. In particular, the depth to which asco'carps of each form are inserted in the host needle, and the character of the stromatic lines produced by each form are useful guides for identification. Form A produces many, and form D few black stromatic lines, while forms B & 0 produce few brown stromatic lines. Similarly, ascocarps of forms A. B & D are situated at least partly under the cuticle alone of the host, whereas ¦ascocarps of form C are totally subepidermal. Three of the forms we re recognised also on cones, and two on primary needles, though work on these was limited. Using samples from abroad and on many species of pine the morphology of the four forms was shown to be largely unaffected by variation of host an locality of collection. Each form was related to a distinct cultural type and three forms were shown to occupy a distinct habitat in the field. Form A fruits on senesced needles which have fallen into the litter, and form B on healthy needles killed prematurely by, for example, damage to their branch; while form C fruits on young needles whioh it has infected and killed. Form D is probably mainly an inhabitant of haploxylon pines, and. may replace form A on the senesced needles of these pines.