The biology of Lophodermella conjuncta Darker on Corsican pine needles

Abstract

The biology of Lophodermella conjuncta on Corsiean pine needles was studied. Results of a spore exclusion experiment and histological examination of needles indicated that infection of young current years needles occurred and that the fungus first colonized only the endodermis. Infection remained latent until symptoms developed, from hyphae penetrating the mesophyll from the endodermis, in July of the year following infeetion. Aseocarps were produced on second year needles by mid-August. Ascospores were trapped throughout the year. Infected needles were cast prematurely during the third season. The phenomenon of latent infeetion of pine needles by some pine needle fungi is diseussed.

Histopathology of loblolly pine needles infected by Mycosphaerella dearnessii, the brown‐spot needle disease pathogen

“…However, in particular samples, these adjoining mesophyll cells exhibited an intercellular matrix (Fig. 2 D, E), similar to a stationary interface (WILLIAMSON et al 1976;MITCHELL et al 1978;JEWELL 1990 a, b). This matrix was often observed to coincide with the abnormahty o' f the associated resin duct distal from the symptom lesion (Fig.…”

Succession of fungi and fauna during decomposition of needles in a small area of Scots pine litter

“…literature) are widespread pine-specific fungi which have been recorded frequently on living or senescent pine needles (Gremmen, 1957;1977;Hayes, 1965;Kendrick and Burges, 1962;Minter et al, 1978;Minter, 1981;Mitchell, Millar and Minter, 1978;Mitchell, Millar and Williamson, 1978;Rack and Scheidemann, 1987;Soma and Saito, 1979). These fungi were assigned to one decomposition stage (stage 1), due to uniformity in the mode of colonization (extra-cellular hyphae in the mesophyll) and to coexistence of these species in the same superficial layer (needles shed a few months before sampling date).…”

Short-needle disease of Scots pine: an abnormal needle length distribution

“…In mature needles, defence reactions to fungal infections are restricted to the formation of chemical barriers, such as suberification or impregnation of cells with resinous or phenolic materials (e.g. Mitchell et al 1978). The result of this study was that the abnormal needle length variation was associated with injuries at needle bases, which might be caused by insects feeding on the meristematic tissue of growing needles.…”

“…Wood and Pennypacker (1974) showed that the development of the short-needle disease did not depend on the presence of air pollutants as Gordon (1972) previously suspected. We found that the pathologically short needles had no symptoms of fungal infection, and microscopically, no collapse of mesophyll tissue which is usually associated with the action of fungal parasites (Mitchell et al 1978, Jewell 1993 or hyphae were observed. However, the possible presence of endophytes was not investigated.…”