Notes and brief articles 359 DAMLE, K. (1960). Uncinula tectonae Salm. on Tectona grandis L. Journal of the Indian Botanical Society 39, 243- 258. EFrIMIU, P. (1929). Contribution a l'etude del'evolution nucleaire chez certaines Er ysiphaceae. Bulletin Societe Botanique de Fran ce 76, 10-20. EFTtMIU, P. & KHARBUSH, S. S. (1928). Le development des peritheces et Ie phenomene de la reduction chromatique chez les Erysiphacees. Le Botaniste 20, 157- 190. FEDROV, A. N. A. (1969). Chromosome N umbers of Flowering Plants. Academy of Science, USSR. FLOR, H. H. (1971). Current status of the gene-for-gene concept. Annual Review of Phyt opathol ogy 9, 275-296. HARPER, R. A. (1905). Sexual reproduction and the organ ization of the nucleu s in certain mildews. Carn egie Institute Washirlgton Publication 37, 1 -104. HElM, M . P. (1952). Observati ons sur Ie noyau des Ascomycetes. Revue de Mycologie 17,3-38. HENDERSON, S. A. & Lu, B. C. (1968). The use of haematoxylin for squash preparations of chromosomes. Stain Technology 43, 233-236. JAGTAP, A. P. (1974). Cytological studies in Erysiphe poonensis Kamat. Maharashtra Vidnyan Mandir Patrika 9, 146-153. KAMAT, M . N. & PANDE, A. (1971). Chromosome complements in ascomycetes. Journal of the Shivaji Uni versity 4, 49-5 7ยท KHARBUSH, S. S. & EFTtMIU, P. (1928). Sur les phenomene s de reduction chromat ique dans la famille des Er ysiphacees. Comptes R endues academie Science (Paris) 186, 321-323. KIMBER, G. & WOLFE, M. S. (1966). Chromosome number of Erysiph e graminis. N ature, London 212 , 318-3 19. LU, B. C. (1962). A new fixative and improved propio- nocarmine squash technique for staining fungus nuclei. Canadian Journal of Botany 40, 843-847. McKEEN, W. E. (1972). Somat ic mitosis in Ery siphe graminis hordei. Canadian Journal of Microbiology 18, 1915- 1922. OLIVE, L. S. (1953). The structure and behaviour of fungus nuclei. Botanical Review 19, 439-586. PATWARDHAN, P. G. (1966). Ph.D. The sis, Poona Univer sity. PATWARDHAN, P. G. (1969) . Nucleolar chromosomes in Phylla ctinia yarwoodii Patw. Current Sc ience 38, 70. RAYMOND, J. (1934). Contribution il la connaissance cytologique des Ascomycetes. Le Botaniste 26, 371-537. ROBINOW, C. F. & BAKERSPIGEL, A. (1965). Somatic nuclei and forms of mitosis in fungi. In The Fungi 1. (Ed. Ainsworth, G . C. & Sussman , A. S.), pp . 119-142. Academic Press, New York. ROGERS , J. D. (1973). Polyploidy in fungi. Ev olution 27, 153- 160. SAHAY, B. N ., SINGH, D. N. & DUTTA, B. S. (1965). Cytological studies in Phyllactinia corylea (Pers.) Karst. The Nucleus 8, 157-160. SHARMA, A. K. & SHARMA, A. (1972). Chromosome Techniques. Butterworths, London. STEBBINS,G. L. (1950). Variation and Evolution in Plants. New York : Columbia University Press. TARE, N . B. (1955). The development and cytology of Ery siphe acaciae Blumer . Journal of th e Ind ian Botanical S ociety 34, 92-106. WEL LS, K. (1977). Meiotic and mitot ic divisions in the Basidiomycotina. In M echanisms and Cont rol of Cell Di vision (Ed. Rost, T. L. & Gifford, E.M. Jr.), pp. 337-374. Dowden, Hutchinson, and Ross Inc., Stroudsburg , Pennsyvania. WHEELER, H. (1975). Plant Pathogenesis. Springer-Verlag. Berlin. A SPECIES-SPECIFIC METHOD OF ANALYSING POPULATIONS OF BASIDIOSPORES BY T. J. H. ADAMS, E. N. D. WILLIAMS, N. K. TODD Department of Biological Sciences, University of Exeter, Devon, EX4 4QG AND A. D. M. RAYNER School of Biological Sciences, University of Bath, Clauerton Down, Bath, Avon, BAz 7A Y A method using homokaryotic mycelia to investigate the dissemination and deposition of viable spores of heterothallic basidiomycetes, is described and its application discussed . Methods of estimating the numbers and types of spores in the atmosphere fall into two broad categories. The first is to collect the spores by im- paction onto a sticky surface, and to make a direct count for each species . This method is u seful when the spores can be unambiguously identified, but many basidiomycetes ha ve spores which are ver y similar , and another drawback is that no estimate of the viability of the collected spores can be made; a factor which is very pertinent to ecological studies. The second, which doe s provide some idea of viability, and ma y facilitate identification, involves impaction onto growth media which may be made selective to eliminate competitors. How- ever, it is time-consuming to formulate such media, and they are of little use for separating species with similar ph ysiological requirements . Furthermore, if inhibitory agents are incorporated into the media these may have mutagenic effects, or may select only certain genotypes of a particular species and this will bias any study of the range of genotypes pres ent . The technique described here is a logical extension of this second category , applicable for Tran s. Br , mycol. Soc. 82 (2), (1984) Printed in Great Britain