Probatova N.S.. Rudyka E.G.. Gromik S.L
Caryotaxonomy of the genus Milium L. and some related genera of grasses (Poaceae)
Year: 2000, Issue: XLVI, Pages: 105 - 146
The analysis of chromosome numbers and some data on caryotypic morphology of the members of the grass genus Milium L., in connection with its taxonomy, biogeography and evolution, as well as of some related genera of the tribe Aveneae was carried out Within the genus Milium a considerable variability of chromosome numbers is known (2n = 8, 10, 14, 18, 28, 42), and four basic numbers (x=4, 5, 7, 9) characterize various subspecies of M. vernale Bieb. s.l. Taxonomic position of the genus Milium within the Family Poaceae, history of its studies, taxonomic composition, distribution, ecology and biological features of its members are under consideration. A key for species and infraspecific taxa is compiled. Basing on results of the studies of morphology, biogeography and caryology, the phylogenetic relations within the genus Milium arc discussed, and the main evolutionary trends in Miliun are shown. A considerable similarity of caryotypcs in two species with the minimal diploid chromosome number 2n =4 -Colpodium versicolor and Zingeria biebersteiniana was revealed, which is considered to be not only a consequence of some parallel evolution within two large tribes of Poaceae-- Aveneae (Zingeria) and Poeae (Colpodium), but it also prouves their more or less close relations. The monotypie genus Zingeriopsis, intermediate between Zingeria and Colpodium (and. probably, also with x=2) proves this consideration. The main trends of the caryotypic evolution within tribes Avencae and Poeae arc discussed. The tendency of transformation of the ancestral basic chromosome number x=7 is shown within the tribes Avencae and Poeae, especially by the way of consequent reduction of this basic number, but the dominant tendency in both tribes was polyploidization, on the base of x=7, which is common for all progressive genera of these tribes.