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(2019)
Eine achtköpfige Delegation der Universität Potsdam (UP) besuchte vom 18. bis 21. November 2018 die Tel Aviv University (TAU) in Israel. Die Kooperation zwischen beiden Einrichtungen wurde durch einen »staff exchange« intensiviert. So konnten Mitarbeiter*innen der UP ihren Gegenpart an der TAU kennenlernen und sich inhaltlich austauschen. Der vorliegende Bericht basiert auf Gesprächen mit drei der insgesamt fünf Bibliotheksdirektorinnen sowie zwei weiteren Kolleginnen aus dem Bereich Erwerbung und Katalogisierung. Dabei wurden unterschiedliche Themenbereiche aus dem Bibliothekswesen und die Sicht beziehungsweise der Stand dazu an der TAU und der UP angesprochen. Der vorliegende Bericht geht auf die Themenfelder Bibliothekssystem, Open Access und Bibliothek als Raum ein.
The ecological benefits of polyploidy are intensely debated. Some authors argue that plants with duplicated chromosome sets (polyploids) are more stress-resistant and superior colonizers and may thus outnumber their low ploidy conspecifics in more extreme habitats. Brachypodium distachyon (sensu lato), for example, a common annual grass in Israel and the entire Mediterranean basin, comprises three cytotypes of differing chromosome numbers that were recently proposed as distinct species. It was suggested that increased aridity increases the occurrence of its polyploid cytotype. Here, we tested at two spatial scales whether polyploid plants of B. distachyon s.l. are more frequently found in drier habitats in Israel. We collected a total of 430 specimens (i) along a largescale climatic gradient with 15 thoroughly selected sites (spanning 114–954 mm annual rainfall), and (ii) from corresponding Northern (more mesic) and Southern (more arid) hill slopes to assess the micro-climatic difference between contrasting exposures. Cytotypes were then determined via flow cytometry. Polyploid plants comprised 90% of all specimens and their proportion ranged between 0% and 100% per site. However, this proportion was not correlated with aridity along the large-scale gradient, nor were polyploids more frequently found on Southern exposures. Our results show for both spatial scales that increasing aridity is not the principal driver for the distribution of polyploids in B. distachyon s.l. in Israel. Notably, though, diploid plants were restricted essentially to four intermediate sites, while polyploids dominated the most arid and the most mesic sites. This, to some degree, clustered pattern suggests that the distribution of cytotypes is not entirely random and calls for future studies to assess further potential drivers.