Cytotaxonomy of Liliales

Abstract

On the basis of cytological data and with consideration of a wide literature, the taxonomy of Liliales as delimited by Hutchinson are represented. A review about phylogeny of Liliaceae in different systems is given. In the main part a great number of tribes of Liliaceae are treated with regard to delimitation, affinities and evolution. Further a cytological assessement of evolution and interrelationships of different families of Liliales with Liliaceae were indicated. Ultimately the lines of evolution of Liliaceae were debated. Especially e. g. the following more important conclusions were outlined: The primitive tribe Heloniadeae might have descended from Juncaginaceae. The potentiality of Asphodeleae as the progenitor of different tribes of Liliacae has been confirmed. The tribe Ophiopogoneae is quite homogeneous, whereas the tribe Hemerocalleae has been indicated as an unnatural group, and some genera are transfered under Agavales. The origin of Amaryllidaceae from Tulipeae and Hemerocallideae is confirmed. Agapantheae is an advanced representative of the subfamily Allioideae of Amaryllidaceae. In Polygonatum the “latifolium” type of “alternifolia” represents the primitive state with 9 or 10 as basic chromosome number. The midtertiary origin of Smilacina has been supported. Disporum of pleistocene origin is likely to have given rise to Polygonatum through diminution in chromosome size and asymmetry on the one hand and Smilacina on the other, with increase in asymmetry. Asiatic species of Disporum representing the most primitive form and have been reponsible for the evolution of the American species of Disporum and in another line of Aspidistreae, Convallarieae, and Peliosantheae. The creation of the tribes Dianelleae and Veratreae is supported. With the exclusion of Calochortus and Lloydia, Tulipeae would represent a homogeneous grouping. In Scilleae, Scilla sibirica with n = 6 chromosomes represents a primitive form. Muscari is to be separated into three genera. The Tulipeae should be divided into several assemblages which represents origin from a common stock.

Genome Size Dynamics and Evolution in Monocots

“…These data show a narrow range of genome sizes from 1C = 0.41 pg in Narthecium ossifragum to 6.75 pg in Dioscorea elephantipes. Although all families are characterized by possessing small to very small chromosomes (e.g., see [88][89][90][91]), high levels of polyploidy have been reported, particularly in Burmanniaceae and Dioscoreaceae in which chromosome counts of 2n = 136 and c. 140, respectively, have been recorded [92][93][94]. Such karyotype information suggests that genomes larger than 6.8 pg may well be found as representation of genome size data improves.…”

“…Such karyotype information suggests that genomes larger than 6.8 pg may well be found as representation of genome size data improves. Nevertheless, since increases in ploidy are often accompanied by decreases in chromosome size (as noted in Nartheciaceae by Larsen [95] and by Sen in Burmanniaceae [89]), the upper limit of genome size in this order is unlikely to be very large.…”

A Chloroplast Phylogeny of Agavaceae subfamily Chlorogaloideae: Implications for the Tempo of Evolution on Serpentine Soils

“…Notably, all members of Chlorogaloideae have a bimodal karyotype, in which chromosomes fall into two distinct groups of sizes (Sato 1935;Gould 1942;Sherman 1969;Cave 1970;Fernandez and Daviñ a 1991). The discovery of this character first indicated a close relationship to members of Agavaceae, in which the presence of bimodal karyotypes has long been recognized (McKelvey and Sax 1933;Akemine 1935;Sato 1935;Watkins 1936;Granick 1944;Cave 1948Cave , 1970Sen 1975;Tamura 1995;Pires et al 2006;McKain et al 2012).…”

Documentation of the Chromosome Number for <I>Zigadenus glaberrimus</I> (Liliales: Melanthiaceae) and its Significance in the Taxonomy of Tribe Melanthieae

“…A probable base chromosome number of x = 8 has often been postulated for tribe Melanthieae (summary in Zomlefer et al 2006a), and multiples of this number are prevalent in other genera of the tribe: ( Fig. 1 ;Sen 1975;Lowry et al 1987;Tamura 1995;Zomlefer 1997): Amianthium (2n = 32), Anticlea (2n = 32), Schoenocaulon (2n =16), and Veratrum (including Melanthium; 2n = 16, 32, 64, 80, 96). Zigadenus, another exception to an octomerous count, is of particular interest due to its significant position in the evolution of Melanthieae as the functional outgroup of the tribe, and the verified count allows formal reassessment of the base number for tribe Melanthieae.…”