Rudolf Freisleben

Rudolf Theodor Woldemar Freisleben (born March 11, 1906 in Dresden ; † October 9, 1943 in Dresden) was a German botanist , crop scientist and geneticist . In 1942 he was the first scientist to succeed in producing a mildew-resistant variety of barley through the use of radiation-induced mutagenesis , which enabled him to demonstrate the practical use of this method for the breeding of crops .

Life

Rudolf Freisleben was born in Dresden in 1906 as the son of a factory owner. From 1925 to 1930 he studied natural sciences at the University of Munich , the University of Leipzig and the TU Dresden . In 1930 he passed the state examination for higher teaching qualifications and then worked as a student trainee and assessor, later as an assistant at the TU Dresden.

In 1932 he received his doctorate at the TU Dresden and then worked at the Tharandt Forestry School on mycorrhizae in forest trees and heather plants (Ericaceae) . In 1934/35 he received a scholarship from the Akademikerhilfe of the Notgemeinschaft der Deutschen Wissenschaft , which enabled him to work at the Institute for Plant Cultivation and Plant Breeding at the University of Halle with Theodor Roemer . In 1935 he set up a department for mutation research at his institute , the management of which he transferred to Freisleben, so that in July 1935 he finally got a scheduled position as an institute assistant. In 1936 he completed his habilitation with a genetic thesis and was appointed lecturer.

From 1937 he worked on the barley range collected during the German Hindu Kush Expedition and continued research on the genetics of polyploid cultivars. Roemer recognized the potential of the induction of mutations and expanded the free life research department, which from 1937 was called the Department of Cytogenetics. In 1938, Freisleben coined the term " applied cytogenetics"

From 1935, Freisleben, who had joined the SA in 1933, completed military exercises. In 1937, Freisleben was accepted into the NSDAP . In 1939 he was finally called up for military service.

In 1941, Freisleben took part in a botanical collective expedition to the central mountain range of the Balkans carried out on behalf of the Kaiser Wilhelm Institute for Biologists, the Reich Research Council and the High Command of the Wehrmacht , which had the task of collecting primitive and wild forms of cultivated plants, especially grain collect and carry out plant geographical studies. In addition to Freisleben, the botanists Friedrich Markgraf from the Botanical Museum in Berlin and Walther Hoffmann (* 1910, † 1974) from the Kaiser Wilhelm Institute for Breeding Research in Müncheberg took part in the expedition led by the agricultural scientist and plant breeder Hans Stubbe . The participants in the expedition were released from active military service and instead were given military service, they wore uniforms and were accompanied by military personnel. As a result, the expedition brought over 2000 seed samples and as many dried plant specimens to Germany.

In 1942, Freisleben took part in a second expedition to Crete and the Peloponnese , also led by Stubbe . This time the botanist Karl Heinz Rechinger , the botanist Werner Rothmaler and the zoologist Otto Wettstein-Westersheimb , who was the head of the herpetological collection in the Natural History Museum in Vienna , took part in addition to Freisleben . On this expedition, too, the scientists were in uniform and were supported by German soldiers and in the Peloponnese by the Italian Wehrmacht.

Freisleben showed great talent in the field of plant breeding and was considered to be Roemer's most gifted assistant. In the field of botany he was one of the 10 scientists who received the highest funding between 1934 and 1945.

In 1942 he was able to prove that an archetype of barley collected during the Hindu Kush expedition had been cultivated directly. After trying in vain for years to breed a powdery mildew-resistant barley variety by crossing experiments, Freisleben succeeded in inducing flour roughness resistance through the action of X-rays on the seeds. The disease-resistant barley variety produced in this way was not only of great practical importance for increasing agricultural yields, it was much more that Freisleben was the first to prove that radiation mutagenesis in plant breeding could be used specifically to create new plant properties.

During the negotiations for the establishment of the Kaiser Wilhelm Institute for Cultivated Plant Breeding, Freisleben was recommended by its initiator Fritz von Wettstein as head of department. The future head of the institute, the agricultural scientist and plant breeder Hans Stubbe, knew Freisleben from the Balkan expeditions and also tried to get his approval. However, the collaboration ultimately failed because Freisleben and Stubbe were working on very similar research fields that were difficult to distinguish from one another. Freisleben, who had hoped that Fritz von Wettstein would be appointed director of the new institute, did not want to submit to Stubbe and therefore turned down the position offered to him as head of department.

In April 1943 he was appointed adjunct professor by the University of Halle and a little later received a call to the University of Würzburg. However, he could no longer take up this professorship because he died on October 9, 1943 after a short illness in the Dresden hospital. His urn grave is on the Tolkewitz urn grove in Dresden.

Publications (selection)

• About experimental mycorrhiza formation in Ericaceae. In: Reports of the German Botanical Society. Volume 51 (8), November 1933, pp. 351-356
• On the question of mycotrophy in the genus Vaccinium L. In: Yearbook of scientific botany, 80th year, 1934. pp. 421–456.
• Further investigations into the mycotrophy of the Ericaceae. Borntraeger, 1935
• The barley of the German Hindu Kush Expedition 1935 (results of the German Hindu Kush Expetdition IV) , Kühn Archive Volume 54, Halle, 1940
• The phylogenetic importance of Asian barley. In: Der Züchter, 12th year (11), November 1940, pp. 257–272
• together with A. Lein: About the discovery of a mildew-resistant mutant after X-ray irradiation of a susceptible pure line of spring barley. In: Naturwissenschaften, Volume 30 (40), October 1942, p. 608
• A new find from Hordeum agriocrithon Åberg. In: Der Züchter, 15th year (2), February 1943, pp. 25–29
• The application of mutation triggering of chromosome duplication and species crossings in plant breeding. 1940.

Web links

• Entry on Rudolf Freisleben in the Catalogus Professorum Halensis

Individual evidence

1. ↑ ^{a b} Susanne Heim: Calories, Rubber, Careers: Plant Breeding and Agricultural Research in Kaiser Wilhelm Institutes, 1933–1945. Wallstein Verlag, 2003, p. 219
2. ^ Biography of Rudolf Freisleben in the Catalogus professorum halensis on the homepage of the University of Halle, accessed on March 4, 2016
3. ↑ List of doctoral candidates at TU Dresden for the period 1900 to 1945 - F. on the homepage of the Technical University of Dresden, accessed on March 4, 2016
4. ^ ^{A b} D. Mettin, WD Blüthner: The development of cytogenetic research at the Plant Breeding Institute Halle / Hohenthurm with special reference to aneuploidy in cereals. In: Euphytica. 89th year (1), January 1996, pp. 125-141
5. ↑ Rudolf Freisleben: Cytogenetics and Plant Breeding. In: Festschrift for the 75th anniversary of the agricultural institutes of the Martin Luther University Halle-Wittenberg. Kühn Archive, Volume 50, 1938, pp. 315–338
6. ↑ Karl Hammer, Lufter Xhuveli: Hans Stubbe (1902-1989). (Translated from the Albanian by Merita Hammer-Spahillari), In: Karl Hammer, Thomas Gladis, Marina Hethke (eds.): Pumpkin, Kiwano & Co. - on the benefits of diversity. Volume 1: Exhibition catalog, Kassel 2002, pp. 118–121
7. ↑ ^{a b c d e} Rudolf Maier: From the Kaiser Wilhelm Institute for Crop Plant Research in the Vivarium (Vienna) and at Tuttenhof near Korneuburg (Lower Austria) to the Leibniz Institute for Plant Genetics and Crop Plant Research in Gatersleben (Germany). In: Writings Association for the Dissemination of Scientific Knowledge. 142, 2008, pp. 43-82
8. ↑ Lothar Mertens : "Only politically worthy people". DFG research funding in the Third Reich 1933–1937. Akademie Verlag, Berlin 2004, p. 189
9. ↑ Ute Deichmann: Biologists under Hitler. Harvard University Press, 1999, p. 110
10. ^ Municipal cemetery and funeral system Dresden: The urn grove in Dresden - personalities. ( Memento of the original from March 4, 2016 in the Internet Archive ) Info: The  archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. , accessed March 4, 2016