Search

Two new species of rust fungi, Melampsora salicis- purpureae sp. nov. and M. salicis- argyraceae sp. nov., and a new record, M. iranica, are described from China based on morphological characteristics and molecular phylogeny of the internal transcribed spacer (ITS1 and ITS2) regions including 5.8S of the ribosomal RNA gene. Melampsora salicis- purpureae on Salix purpurea was characterized by amphigenous uredinia, subepidermal teliospores, and relatively shorter teliospores and amphigenous telia. Melampsora salicis- argyraceae on S. argyaceae possessed sparse spines on urediniospores, epiphyllous telia and subepidermal teliospores with slightly thickened apex. In addition, specimens on S. alba and S. psammophyla were identified as M. iranica. [ABSTRACT FROM AUTHOR]

MeOH and water extracts were obtained from 16 species of infected leaves with rust fungi belonging to 18 species in 6 families: Pucciniaceae, Melampsoraceae, Coleosporiaceae, Pileolariaceae, Phragmidiaceae, and Phakopsoraceae. All the extracts of rust-infected plants with telia showed the teliospore-inducing activity for wheat leaf rust ( Puccinia recondita f. sp. tritici). [ABSTRACT FROM AUTHOR]

Abstract Using a leaf disc method, 19 isolates of the poplar rust, Melampsora larici-populina , and one isolate of M.?populnea from England were inoculated on to 25 poplar clones belonging to Populus nigra and P.?trichocarpa , and hybrids between P. deltoides and P. nigra , P. deltoides and P. trichocarpa , P.?tacamahaca and P.?trichocarpa , and P. alba and P. tremula . Disease was scored based on the pustule area and inoculum density. In terms of whether sporulating uredinia formed, the 19 isolates showed seven different patterns to the tested poplar clones. The majority of the rust isolates infected P. nigra P3090 and Vereecken, P.?nigra ?? P. deltoides Casale and Tasman, P. tacamahaca ?? trichocarpa 36 and Balsam Spire, and P.?trichocarpa Blom. Populus trichocarpa ?? P. deltoides 69039/4 was infected by only three isolates collected from southern England. No visible symptoms appeared on P. alba ?? P. tremula Tower and P.?trichcarpa? ? P. deltoides ?? P. deltoides 76028/5 in inoculations with M. larici-populina isolates. Populus alba? ?P.?tremula Tower was infected only by M. populnea . When M. larici-populina isolates were tested using AFLP, no differences were found either between isolates from different geographical regions or between those having narrow spectrum of virulence and those showing wide spectrum of virulence on the tested clones. The results suggest that the UK rust populations possess virulences which were found in races E1, E2, E3 and E4 in continental Europe and that rust having virulence patterns similar to race E4 has occurred in UK poplar plantations since 1996. [ABSTRACT FROM AUTHOR]