Biologia 68/4: 606—612, 2013Section BotanyDOI: 10.2478/s11756-013-0186-2Geographical separation of diploid and triploid cytotypesof Allium scorodoprasum in LithuaniaBirut˙ e Karpavi?ien˙ eNature Research Centre, Institute of Botany, ?ali? uj? u E?er? u 49, LT-08406 Vilnius, Lithuania;e-mail: birute.karpaviciene@gmail.comAbstract: The aim of this study was to determine the geographical and ecological distribution of Allium scorodoprasumcytotypes in Lithuania. 46 populations were studied: environmental variables were recorded and somatic chromosomenumbers of 797 individuals from all populations were assessed. Diploids were found in 13 populations in the northern partof the study area, while triploids occurred in 33 populations from the western part of Lithuania. A. scorodoprasum frequentlyoccurred in river valleys, particularly in the rarely f looded high level f loodplains or on lower terraces. Only one populationwas recorded in Alno-Ulmion forest and three on the Glechometalia hederaceae forest edges, while 42 populations occurredin mesophilous or semidry Arrhenatheretalia elatioris, Mesobromion erecti and Trifolio-Geranietea sanguinei grasslands. Nodistinct dif ferences in relative frequencies of diploid and triploid cytotypes in dif ferent plant communities were found whereasthe soil chemical composition between the habitats of both cytotypes dif fered statistically. These dif ferences however wereindicative of the geographical separation of habitats rather than ecological dif ferentiation between the two cytotypes. Theresults suggest that there were at least two separate roads of colonization of diploid and triploid A. scorodoprasum intoLithuania.Key words: Allium scorodoprasum; chromosome number; cytotype; distribution; ploidy level; LithuaniaIntroductionPolyploidy is ubiquitous phenomenon among angio-sperms that may have led to a dramatic increase inspecies richness (Soltis et al. 2009). Ploidy dif ferencesare not restricted to comparisons between species butalso occur frequently within species (e.g., Baack, 2004;Suda et al. 2007; Duchoslav et al. 2010; Šafá?ová et al.2011, Karpavi?ien˙ e 2012). Many studies of intraspecif icpolyploid complexes have shown that cytotypes are ge-ographically segregated (e.g., Li 2005; Mandáková &M¨ unzbergová 2006; Suda et al. 2007). The spatial seg-regation is explained by minority cytotype exclusion(Levin 1975), dif ferences in ecological requirements (e.g.Te Beest et al. 2012), various spatio-historical processes(Mandáková & M¨ unzbergová 2006) as well as the traitsof reproductive biology (Mráz et al. 2012). Generally,the frequency of diploids strongly and regularly de-creases along the S–N zonal gradient (Brochmann etal. 2004; Peruzzi et al. 2012). Distributional data ofpolyploids and their diploid progenitors are importantin answering many questions concerning polyploid ori-gin, spread and niche dif ferentiation. However, casualsampling of a small number of plants is usually able todetect the most frequent cytotypes but fails to detectrare ones (Duchoslav et al. 2010).Allium scorodoprasum L. is a bulbous geophytewith a submediterranean-subcontinental-european dis-tribution (Meusel et al. 1965). In Lithuania the speciesoccurs at the northeastern limit of its range (Jankevi-?ien˙ e et al. 2003) and is enlisted in the Red Data Book(Karpavi?ien˙ e 2007a). In Lithuania A. scorodoprasumis found in the western part of the country andin the western part of Latvia and Estonia as well,close to the Baltic Sea (Jankevi?ien˙ e et al. 2003).The species consists of three cytotypes varying fromdiploids to tetraploids (2n = 16; 24; 32). The diploidand triploid cytotypes prevail in Europe, and are re-ported from Austria (e.g. Wetschnig 1992), Slovakia(Murin & Feráková 1988), Finland and Ukraine (e.g.?Astr¨ om & Hæggstr¨ om 2003), Lithuania (Karpavi?ien˙ e2007b). Diploid plants are reported from EuropeanTurkey ( ¨ Ozhatay et al. 1993), Italy (L¨ ove & L¨ ove 1982),Macedonia (Šopova 1972), Slovenia (Murin & Feráková1988), British and Irish Isles (Al-Bermani et al. 1993),Belarus (Semerenko, cited in Agapova et al. 1990), Swe-den (L¨ ovkvist & Hultg? ard 1999). The triploids are regis-tered in Germany (Ohri & Pistrick 2001) and the CzechRepublic (Měsí?ek & Jav?rková-Jarolímová 1992). Thetetraploids are the rarest ploidy level in A. scorodopra-sum and are found in Turkey ( ¨ Ozhatay 2002), Italy (Ja-cobsen & Ownbey 1977) and the Netherlands (e.g. VanLoon 1982). However, only single chromosome countsper populations are reported in most of these studies.The most detailed information on geographical distri-bution of A. scorodoprasum cytotypes on a regionalscale are obtained for Slovakia by Murin & Feráková(1988), where diploids and triploids are found in ap-c ? 2013 Institute of Botany, Slovak Academy of Sciences
