Elias Melin: Pioneer Leader in Mycorrhizal Research

Abstract

Elias Melin was born in 1889 and died four months before his 90th birthday in 1979. His father, Samuel Melin (1849-1931), was a pastor in the Swedish Lutheran church, and Samuel's father in turn, Anders Svensson (1804-1866), was a farmer. Elias Melin's grandfather on his mother's side, Carl Wictor Stenborg (1823-1878), was a very active and successful man. At the age 15, he went to Germany to learn.the profession of saddler, and after two years returned to Sweden to start his own saddlery in Stockholm. Ten years later he married the daughter of his German master craftsman. By the time he was 42 his frugality allowed him to purchase a large estate, Sk~imningsfors, in the province of V~isterg6tland, near Lake V~ittern. He died before his grandson was born, but as a young boy Elias visited his grandmother and enjoyed the beautiful manor house and garden. Much of the initiative and ambition that characterized Carl Wictor Stenborg seems to have been inherited by his grandson, Elias. Samuel Melin and his wife Hilda had seven sons and two daughters. Elias was number three in this large circle. His six brothers all became pastors in the Swedish church. Only Elias chose a non-theological career. Elias Melin went to school at the old town of Skara, an ancient bishop's see. In 1907 he started his academic studies at the University of Uppsala. Very soon he joined the large group of students attracted to the famous professor of plant biology and sociology, Rutger Sernander. Early on, Melin turned his attention toward the genus Sphagnum, and his first publications dealt with the biology and cytology of Swedish Sphagnum species. Hence, he was well prepared when Sernander proposed that be should investigate the extent to which different types of North Scandinavian wetlands (mires) could be drained and then converted to productive forests. LINDEBERG In his doctoral thesis, published in 1917 (10), Melin first presented comprehensive study of the plant associations in different mires, and, second-ly, an investigation into the vegetation and, especially, the growth of Scots pine and Norway spruce on trenched peat bogs. In this connection he made the important observation that healthy and vigorous seedlings always had typical ectomycorrhizae, whereas weak and slow-growing seedlings only had "pseudo-mycorrhizae" (short roots attacked by parasitic mycelia that pene-trate the cells but form neither Hartig net nor sheath). He concluded that, at least on drained peat bogs, the formation of ectomycorrhizae was necessary for the normal development and growth of coniferous seedlings. After this discovery he devoted his life to the study of the structure, function, and importance of the ectomycorrhiza. Melin's doctoral thesis was given the highest possible grade, "Laudatur", which at Uppsala University has always been restricted to dissertations of rare distinction. He soon became docent (assistant professor) in plant biology Professor Sernander's department, but after a year moved to the Royal College of Forestry in Stockholm as docent in forest botany, an office that he held for seven years (1920-1926). In this period, Melin carried out the fundamental work on the structure and fungal components of the mycorrhiza in forest trees that has given him a worldwide reputation. Already in his thesis, Melin stated that experimental work was needed for a deeper understanding of mycorrhiza, incuding studies on pure cultures of mycorrhizal fungi and tree seedlings, as well as controlled (in vitro) synthesis of mycorrhiza. To acquire the necessary experience of microbiological tech-niques, he visited the laboratories of two famous microbiologists on the continent, Martinus Willem Beijerinck in Delft, and Hugo Miehe in Berlin. In 1921 he published in Svensk Botanisk Tidskrift (11), a brief account of the isolation of fungal symbionts from pine and spruce mycorrhizae. This paper included descriptions of the synthesis of mycorrhizae in axenic seedlings of conifers by inoculating them with pure cultures of mycorrhizal fungi. Taxonomic identification of the isolates was not possible, since they did not produce fruit bodies in vitro. Consequently they were given the preliminary names Mycelium Radicis silvestris ~, i~ and % and Mycelium Radicis Abietis, respectively. The presence of clamp connections on the mycelia indicated that they represented Hymenomycetes or Gasteromycetes. Brefeld (2), Romell (31) and others had stated that spores of various Boletus species would not germinate in laboratory media. Therefore Melin used the tissue-culture method devised by Duggar (3) to obtain pure cultures of these and other species that in nature are associated with specific forest trees. Even this method, of course, was limited because many presumptive symbionts could not be cultivated on laboratory media. However, a number of isolates were obtained from various Boletus (sensu lato) species and other www.annualreviews.org/aronline Annual Reviews