Abstract: Using optical and scanning electron microscopy, we completed a palynological study of the subtribe Artemisiinae (Asteraceae, Anthemideae), which started in previous paper. This contains different genera with systematic position that, many cases, has been controversial. There is group closely related to Artemisia, another one more Chrysanthemum sensu lato. We confirm existence two pollen morphological patterns ‐ concerning exine ornamentation tribe Anthemideae as currently...

The geographic distribution of the genus Plectocephalus comprises a single species in Ethiopia, two North America and possibly four more South America, striking disjunction that is exceptional for genera tribe Cardueae. enormity this cast doubts on precise taxonomic delineation genus, which not unanimously recognized as natural entity. aims study were to define generic boundaries formulate hypothesis would explain its range. A combined molecular approach, using nuclear internal transcribed...

Abstract Genome size evolution and its relationship with pollen grain has been investigated in sweet potato ( Ipomoea batatas ), an economically important crop which is closely related to diploid tetraploid species, assessing the nuclear DNA content of 22 accessions from five ten varieties two outgroup taxa. Nuclear amounts were determined using flow cytometry. Pollen grains studied scanning transmission electron microscopy. 2C hexaploid I. ranged between 3.12–3.29 pg; mean monoploid genome...

Abstract: Using optical and scanning electron microscopy, we carried out a palynological study of some plant species with systematic position that has been controversial. One the taxa belongs to genus Artemisia (Asteraceae, Anthemideae), but described in another (Artemisia incana/Tanacetum incanum). The remaining have named or combined are now considered members small genera mostly segregated from (Ajania, Hippolytia, Kaschgaria, Lepidolopsis, Mausolea, Turaniphytum), belong very close...

Abstract Polyploidy is one of the major evolutionary forces in plants and particular largest angiosperm family, Asteraceae. This chromosome set multiplication directly impacts nuclear DNA contents, terms variation at holoploid monoploid levels. Other karyological changes such as aneuploidy or dysploidy might produce genome size alterations well, therefore playing also a relevant role forces. All these factors may promote speciation, thus having systematic implications. In this paper we...

Abstract Hybridization has played an important role in Saxifraga evolution causing reticulation and a high number of described hybrids, but little is known about how hybrid speciation had occurred the genus. We focus on group closely related species subsection Triplinervium from Pyrenees, phylogenetic relationships which remain unsolved. Trying to unmask cryptic (or ancient) hybridization processes, we analyze one nuclear (ITS) three plastid regions ( rpl32 ‐ trnL , trnS trnG 3′trnV‐ndhC ),...

The phylogeny of the genus Echinops and Xeranthemum complex were subject a previous molecular study tribe Cardueae. An electronic microscope survey pollen morphology ultrastructure is presented for all genera belonging to these groups, allowing four types be identified. exine pattern indicates that there are two in (including Acantholepis), although no differences have been found between sections Echinops. First, annual species Acantholepis orientalis show type differs from perennial former...

A survey of pollen morphology and ultrastructure within the Rhaponticum group, using both scanning transmission electron microscopy, revealed two types. Most representatives group exhibited Serratula-type pollen. The exceptions were genus Oligochaeta, with Centaurea jacea-type pollen, Myopordon, types Phylogenetic inference indicated that Jacea-type is derived from fact Myopordon a series types, Serratula type to Jacea type, suggests transition one form another has occurred in genus....

In an attempt to resolve whether two putative carlaviruses, potato rough dwarf virus (PRDV) and P (PVP), reported infecting in Argentina Brazil, respectively, are the same genus Carlavirus , they were characterized using nucleotide sequence analysis, serology bioassay. For PRDV PVP, sequences of 2016 1492 bp, obtained. Similarity searches coat‐protein amino acid presence nucleic‐acid‐binding protein exhibiting characteristic motif C‐X 2 ‐C‐X 11 4 ‐C, highly conserved showed PVP be members ....

We carried out a cytogenetic and isozymic study of Artemisia molinieri Quézel, Barbero, & R. Loisel (Asteraceae, Anthemideae), narrow endemic species limited to two populations in southeastern France. Fine karyotype analysis, including fluorochrome banding, enabled us discuss the systematic affinities this taxon, which is closely related abrotanum L. chamaemelifolia Vill. Isozyme electrophoresis showed higher genetic variability than expected for plant with very restricted geographic...

Abstract In two rye cultivars and four inbred lines, derived from different source populations, the extent of polymorphism in distribution constitutive heterochromatin was investigated by means Giemsa C‐banding method. Between populations only slight differences appeared, therefore a close relationship has to be assumed. Within open‐pollinated wide range variation found not for telomeric, but also interstitial chromosomal bands. Even intracellular between homologous chromosomes observed...

The pollen of 34 individuals representing the 10 species and subspecies section Erythrostictus (Schlecht.) Bentham 3 Cymbanthes in genus Androcymbium Willdenow was examined with scanning electron microscopy to investigate degree morphologic differentiation within between these two sections genus. Diporate morphology observed for all taxa except capense (L.) Krause (section Cymbanthes), which triporate. Given specific importance traditionally given this character, some doubt is cast upon...

Pollen characters in 16 southern African type specimens of Androcymbium Willd. that represent the three sections into which genus is presently divided (Androcymbium, Dregeocymbium and Erythrostictus), were examined to assess possibility sectional characterization based on pollen traits explore relationship between geo­graphic species distribution. Differences grain size, shape, number apertures exine pattern, observed. Principal Component Analysis, using both qualitative biometric...