Аннотация:Lotus comprises ca. 130 species of Old World herbs, semishrubs
and shrubs, including important pasture crops and a model
legume, L. japonicus. Earlier nrITS-based phylogenies were
incongruent with all taxonomic classifications of the genus. In
particular, members of the former genus Dorycnium were unexpectedly
placed near species of L. sect. Lotus. We present a global
phylogenetic study of Lotus that uses both plastid (psbA-trnH IGS
and rps16 intron) and nuclear (ITS and ETS) markers. The rooting
of the Lotus phylogeny, its major clades and basic biogeographic
patterns are discussed. The placement of the segregate genera
Dorycnium and Tetragonolobus in the synonymy of Lotus was
confirmed. Analyses of plastid data strongly supported a basal
split of Lotus into two clades, one comprising species of sect.
Lotus plus those traditionally placed in Dorycnium and the other
including the rest of the species. The former clade has a centre of
species diversity in Europe and N Asia, and the latter in Macaronesia,
Africa and S Asia. Only the “Southern” clade is resolved
in analyses of nrITS and nrETS data. Trees inferred from plastid,
nrITS and nrETS data shared the occurrence of several smaller
clades corresponding to traditionally recognized infrageneric taxa
or species groups as well as the occurrence of some well-supported
clades that differ from traditional taxonomic concepts. Several
instances of incongruence were documented between nuclear and
plastid markers and between the two nuclear markers, possibly
resulting from reticulate evolution. The extant geographic patterns
of Lotus are likely biased by at least one round of area fragmentation
followed by expansion coupled with extensive speciation
associated with the complex history of the Mediterranean biome.
Lotus corniculatus complex that belongs to the section Lotus is
the most agriculturally important, but taxonomically problematic
group of the genus. The presence of at least two ploidy levels and
interspecific hybridization confuses the system of the group. Phylogenetic
relationships among L. corniculatus complex and other
groups of the section Lotus vary in reconstructions inferred from
different DNA markers. However, all studies clearly demonstrate
a highly supported monophyly of the L. corniculatus complex.
Phylogenetic analysis of the section Lotus using trnF-L IGS and
trnL intron of cpDNA revealed taxonomic significance of indels
in these DNA regions. A haplotype network of the L. corniculatus
complex constructed using statistical parsimony method in TCS
program allowed to make the following suggestions concerning
phylogeography of the group: we revealed a specimen of uncertain
morphology with a haplotype related to Lotus conimbricensis
(the closest relative of the L. corniculatus complex), which may
shed light on the origin of the complex; a haplotype from one of
West European glacial refugia (Systema Central, Spain) found in
L. alpinus is the closest to a hypothetical ancestral haplotype of
the L. corniculatus complex; derived haplotypes were spreading
eastward from W. Europe and gave two peaks of diversity: high
in C. and E. Europe and a smaller one in Asian part of Northern
Eurasia. The origin of East African and Japanese lineages of the
complex is also discussed.