Taxonomic notes on the genus Otoptera (Phaseoleae, Fabaceae) in southern Africa

A taxonomic study of the genus Otoptera (tribe Phaseoleae) is presented. This distinct genus consists of two species, O. burchellii in southern Africa (Namibia, Botswana, South Africa and Zimbabwe) and O. madagascariensis endemic to Madagascar. The two species differ in the shape and size of leaflets, size and orientation of the spur located at the base of the wing petal, and also by size of the pod. A key to the two species is provided. This study focuses mainly on the southern African O. burchellii DC., which is described and illustrated. The species name is lectotypified and the known geographical distribution is recorded for the first time.     

A rare new species of Polhillia (Genisteae,Fabaceae)

The new species Polhillia ignota Boatwr. is described. This species is known only from two collections, one between Vredenburg and Saldanha and the other close to Porterville. The new species is most similar to P. obsoleta, which is known only from a few localities around Worcester, in its narrow, sericeous leaflets and flowers of equal size, but differs in its flattened mature leaves with larger leaflets (up to ± 12 mm long), longer pseudo-peduncles (up to ± 15  mm long), denser inflorescences (with up to four flowers), shorter pedicels (1–2 mm long) and non-auriculate wing- and keel petals.     

Chemosystematic evaluation of Aloe section Pictae (Asphodelaceae)

The chemosystematic value of UV-absorbing leaf constituents was considered in previously uncharacterised representatives of Aloe section Pictae, the problematic maculate species complex. Comparative data indicate that the anthrone C-glycoside, 6′-malonylnataloin (7-hydroxychrysaloin 6′-O-malonate) is typical of maculate species in East Africa, but is unconvincing as a synapomorphy for section Pictae. A naphthalene derivative found widely in Aloe, plicataloside, was detected in Aloe greatheadii. Biogeographical trends were observed in the occurrence of the flavonoids isoorientin (luteolin-6-C-glucoside) and isovitexin (apigenin 6-C-glucoside). Isoorientin is a common constituent of tropical and sub-tropical species of Aloe, whereas isovitexin is restricted to a few southern African species. Isoorientin and isovitexin co-occur in the southern African maculate species Aloe parvibracteata, and the disjunct West African maculate species, Aloe macrocarpa. This is the first report of isoorientin and isovitexin in maculate species of Aloe; the presence of flavonoids in section Pictae is of taxonomic interest.     

Reproductive biology of two species of Canavalia DC. (Fabaceae)—A non-conventional wild legume

The reproductive biology of two important species of Canavalia, i.e. Canavalia gladiata and Canavalia virosa, was investigated in detail by studying floral phenology, floral biology including fruit and seed set, breeding system and pollinator's activity. Both the species flower and set their seed primarily from August to December. The study of pollen–-pistil interaction indicated the existence of morphological protandry in both species, and pollen germination occurred only after rupture of the stigmatic surface. This suggests that some form of self-incompatibility operates in these species. Ants were the common vectors tripping the stigma and transporting some foreign pollen. Campylomma verbasci (large black ants) were only seen on the flowers of C. virosa, while Monomorium minimum (small black ants) were restricted to the flowers of C. gladiata. Inadequacy of reliable pollinators and high rate of bud/flower drop may be the main factors for low fruit and seed set in both the species.     

Isoenzyme variation patterns and species concept in Astragalus gossypinus and Astragalus persicus complexes (Fabaceae) in Iran

Isoenzyme electrophoresis was employed to examine the relationships of 21 individuals representing four populations of Astragalus gossypinus complex as well as 20 individuals representing five populations of Astragalus persicus complex. A total of 27 bands from three enzyme systems (superoxide dismutase, esterase, and peroxidase) were obtained. UPGMA clustering method resulted in two distinct clusters for different populations corresponding to the two species complexes analysed. In both species, populations distributed on Alborz mountain range in northern Iran form separated clusters from those distributed on Zagros mountain range in the West. The results also show that both species complexes exhibit a high diversity based on Shannon–Weaver diversity index (H′) compared with other species of Astragalus reported previously. The mean number of bands per each presumed isoenzyme ranges from 2.14 to 3.57. The value of Euclidean distance ranges from 1.251 to 3.152. Our data suggest that both species should be circumscribed wider than that treated by most taxonomists, and several taxonomic names should be reduced under synonymy of the corresponding species.     

Comparative cryopreservation study of trochophore larvae from two species of bivalves: Pacific oyster (Crassostrea gigas) and Blue mussel (Mytilus galloprovincialis)

Oysters and mussels are among the most farmed species in aquaculture industry around the world. The aim of this study was to test the toxicity of cryoprotective agents to trochophore larvae from two different species of bivalves and develop an improved cryopreservation protocol to ensure greater efficiency in the development of cryopreserved trochophores (14 h old oyster larvae and 20 h old mussel larvae) to normal D-larvae for future developments of hatchery spat production. The cryopreservation protocol producing the best results for oyster trochophores (60.0 ± 6.7% normal D-larvae) was obtained by holding at 0 °C for 5 min then cooling at 1 °C min⁻¹ to −10 °C and holding for 5 min before cooling at 0.5 °C to −35 °C, holding 5 min and then plunging into liquid nitrogen (LN), using 10% ethylene glycol. For mussel experiments, no significant differences were found when cooling at 0.5 °C min⁻¹ or at 1 °C min⁻¹ for CPA combinations with 10% ethylene glycol and at 0.5 °C min⁻¹. Using these combinations, around half of trochophores were able to develop to normal D-larvae post-thawing (48.9 ± 7.6% normal D-larvae).     

Comparative pollen morphology of Brachylena, Tarchananthus and two species of Tubulifloridites (Asteraceae) from the Eocene, Knysna Lignite of South Africa

Two fossil taxa Tubulifloridites antipodica and T. viteauensis recovered from the Eocene Knysna Lignite of South Africa were examined with scanning (SEM) and transmission electron microscopy (TEM). The details of their sculpturing and wall structure are similar to the same species of fossil dispersed pollen taxa recovered from southwestern Africa and South America. Fifteen species of the woody South African taxa, Brachylaena (9 species) and Tarchonanthus (6 species) were investigated with SEM and TEM. All of the taxa are tricolporate, spherical to slightly prolate, microechinate to echinate and have a bilayered columellate infrastructure, except B.ilicifolia, which has a single columellate infrastructural level with the “granularization” of the outer portion of the infrastructural layer or the inner layer of the tectum. There is a similar distribution of plesiomorphic and derived pollen characters in a number of aster subfamilies and tribes suggesting a similar evolutionary progression of pollen, and pollen wall character evolution was occurring synchronously in a variety of aster subfamilies during the middle Tertiary and that these unique pollen features may be important to the evolution and diversification of the Asteraceae.     

RPB2 sequences reveal a close phylogenetic relationship between tetraploid Hordelymus and diploid Hordeum species in Triticeae (Poaceae)

The origin of Hordelymus genome has been debated for years, and no consensus conclusion was reached. In this study, we sequenced and analyzed the RPB2 (RNA polymerase subunit II) gene from Hordelymus europaeus (L.) Harz, and its potential diploid ancestor species those were suggested in previous studies. The focus of this study was to examine the phylogenetic relationship of Hordelymus genomes with its potential donor Hordeum, Psathyrostachys, and Taeniatherum species. Two distinguishable copies of sequences were obtained from H. europaeus. The obvious difference between the two copies of sequences is a 24 bp indel (insertion/deletion). Phylogenetic analysis showed a strong affinity between Hordeum genome and Hordelymus with 85% bootstrap support. These results suggested that one genome in tetraploid H. europaeus closely related to the genome in Hordeum species. Another genome in H. europaeus is sister to the genomes in Triticeae species examined here, which corresponds well with the recently published EF-G data. No obvious relationship was found between Hordelymus and either Ta genome donor, Taeniatherum caput-medusae or Ns genome donor, Psathyrostachys juncea. Our data does not support the presence of Ta and Ns genome in H. europaeus, and further confirms that H. europaeus is allopolyploid.     

Molecular systematics and phytochemistry of Rehmannia (Scrophulariaceae)

The relationships between the six known species of Rehmannia were investigated. With regard to the content of iridoid glucosides, caffeoyl phenylethanoid glycosides (CPGs) and ionone glucosides, no conclusions could be drawn. Phylogenetic analysis of DNA sequence data (ITS region, trnL-F region and rps16 intron) reveal a well-resolved topology in which Rehmannia glutinosa and Rehmannia solanifolia and Rehmannia piasezkii and Rehmannia elata are well-supported species pairs. Rehmannia chingii is sister to the rest of the genus, which is congruent with its distribution distant to the other species of the genus.     

Relationships between Bambusa species (Poaceae,Bambusoideae) revealed by random amplified polymorphic DNA

RAPD (random amplified polymorphic DNA) molecular markers were used to investigate relationships between a sample of Bambusa species from South Eastern China that have been placed in Bambusa or in several segregate genera, Dendrocalamopsis, Leleba, Lingnania, Neosinocalamus and Sinocalamus by different authors. On the resultant neighbor-joining tree, a thorny core Bambusa cluster was distinguished, as was a Lingnania group, and a cluster of Dendrocalamus species with more capitate inflorescences. However, Leleba was found to be a polyphyletic group in the present study.     

Hebeloma species associated with Cistus

The genus Hebeloma has a number of species highly specific to Cistus and others that occur with several host genera. This paper discusses the species of Hebeloma that appear to be ectomycorrhizal with Cistus, judging from their occurrence when Cistus is the only available host. The previously unknown species H. plesiocistum spec. nov. is described. We also provide a key to the known Hebeloma associates of Cistus. Molecular analyses based on ITS sequence data further illustrate the distinctness of the newly described species and difficulties in the species delimitation with view to H. erumpens. Specific associations with Cistus may have evolved more than once within the genus Hebeloma.     

Comparative cytogenetics of eight species of Cycloramphus (Anura, Cycloramphidae)

Several aspects of the biology of Cycloramphus species of the Atlantic Forest are still poorly known, which makes it difficult to understand their historical relationships. Therefore, we were stimulated to promote a comparative cytogenetic analysis of several species of the genus Cycloramphus. The study of Cycloramphus acangatan, C. boraceiensis, C. brasiliensis, C. carvalhoi, C. eleutherodactylus, C. fuliginosus, C. lutzorum, and C. rhyakonastes, revealed that these eight species share a diploid number 2n = 26. Cycloramphus fuliginosus presented the most distinct karyotype, due to the presence of subtelocentric chromosomes in pairs 1 and 4. The main diagnostic feature observed in the other species was the presence of one pair of telocentric chromosomes in C. boraceiensis, C. carvalhoi, and C. eleutherodactylus, while the remaining species presented karyotypes composed exclusively of biarmed chromosomes. Constitutive heterochromatin was predominantly located in pericentromeric regions in all species, although additional C-bands detected on telomeric and/or interstitial regions were partially species-specific. Silver staining revealed Ag-NORs located on the pair 6 in six species, whereas C. acangatan presented it on pair 1 and a multiple pattern was observed in C. fuliginosus with three Ag-NOR bearing chromosomes. Fluorescent in situ hybridization using rDNA probe was performed in specimens of C. eleutherodactylus from Paraná, C. lutzorum, and C. rhyakonastes, which did not reveal inactive NOR. Despite the apparent highly conserved diploid number, data on the karyotype microstructure characterize the cytogenetic profile of the genus and may contribute to clarify the phylogenetic relationships among Cycloramphus, the Cycloramphinae, or even the family Cycloramphidae.     

Flavonoids in the species of Cyrtomium (Dryopteridaceae) and related genera

Flavonoids in 19 Cyrtomium, three Cyrtogonellum and two Phanerophlebia taxa were surveyed. Major flavonoids were flavonol O-glycosides based on kaempferol, quercetin, and sometimes myricetin, and C-glycosylflavones, such as isovitexin, vitexin, isoorientin, orientin and their O-glycosides. The C-methylflavanones, farrerol and cyrtominetin, and their 7-O-glucosides were isolated from Cyrtomium devexiscapulae and Cyrtomium laetevirens. Flavanones have been reported from Cyrtomium falcatum sensu lato. Though C. falcatum sensu lato is divided into four taxa, i.e. C. falcatum subsp. falcatum, C. falcatum subsp. australe, C. falcatum subsp. littorale, and C. devexiscapulae, the occurrence of the flavanones was restricted to C. devexiscapulae, and they did not occur in C. falcatum sensu stricto.     

Comparative study of floral development in Onobrychis melanotricha, Hedysarum varium and Alhagi persarum (Leguminosae: Papilionoideae: Hedysareae)

Floral initiation and development of Hedysarum varium, Onobrychis melanotricha and Alhagi persarum was studied using epi-illumination light-microscopy techniques. The studied species belong to the tribe Hedysareae of the inverted repeat loss clade (IRLC clade), which is characterized by missing the large inverted repeat in the chloroplast genome. The main aim of our study was to determine developmental bases for similarities and differences among the three taxa and to verify the position of Alhagi relative to other genera of the IRLC clade. According to our observations, bracteoles are missing in Onobrychis melanotricha, but are present in the other two species. All three species share unidirectional sepal initiation starting with a median abaxial sepal and bidirectional petal initiation. Stamen initiation is unidirectional in all except in the outer stamen whorl of Hedysarum varium, where it is bidirectional. An important ontogenetic feature in O. melanotricha is the existence of five common primordia, which give rise to petal and stamen primordia. Although in H. varium and O. melanotricha common primordia are observed at some stages in floral organ initiations, in Alhagi all organs are initiated separately. Moreover, overlap in time of floral organs initiation occurs in H. varium and O. melanotricha, but not in A. persarum. The carpel initiates concurrently with the petal primordia in all. It might be presumed that Alhagi is primitive in relation to the other studied Hedysareae taxa, due to the presence of bracteoles, the absence of common primordia, and the lack of overlap in time of different organ initiations.     

Comparative study on the delignification of Azadirachta indica (L) Del., wood by Chrysosporium asperatum and Trichoderma harzianum

Structural alterations induced in response to degradation by two white rot Basidiomycetes on the secondary xylem of Azadirachta indica (L) Del., was compared. In vitro decay test was employed to investigate the pattern of delignification of Azadirachta wood by Trichoderma harzianum and Chrysosporium asperatum. Wood samples inoculated with both the strains were analyzed for different periods viz. 30, 60, 90 and 120 days after fungal inoculation. Initially there was no appreciable percent weight loss of the wood blocks but later on (after 60 days) it increased rapidly and was found similar for both the strains (43-46% of wood mass). Samples inoculated with both the strains showed dual pattern of degradation i.e. selective delignification in the initial stage followed by simultaneous rot during advance stage of decay. Separation of the cells due to dissolution of middle lamella was the characteristic feature of both strains but in the advanced stage of decay, formation of erosion troughs were conspicuous in all the cell types. Other features such as cell wall thinning, rounded pit erosion, formation of erosion channels and bore holes were also observed frequently. Initially, fungal invasion started through the vessel lumen, followed by all the cell types of the xylem. From the vessels, mycelia entered into the adjacent rays and parenchyma cells through the pits. In advanced stage, degradation was so pronounced that rays were partially or even completely destroyed while many cells including vessels were either deformed or destroyed due to loss of rigidity of their walls. Structural alterations induced in response to C. asperatum and T. harzianum attack is described in details.     

Fruit anatomy of species of Solanum sect. Acanthophora (Solanaceae)

The fruits of 10 species of Solanum sect. Acanthophora were studied. Cross and/or longitudinal and/or tangential microtome sections, stained mostly with astra blue/basic fuchsin, were made for microscopic examination. Three different kinds of cells were found in the epidermis, immediately below which a hypodermis, consisting in any of four types of structures, was always found. The mesocarp exhibits two histologically differentiated zones, an external one (formed by normal or spongy parenchyma, according to the species), and an internal one, commonly juicy, and with proliferations among the seeds. The diagnostic value of all these structures is assessed. Morpho-anatomical information is used to define fruit types beyond the berry, traditionally described for Solanum, and the probable dispersal syndrome related to them is discussed. Fruit similarities are slightly noticeable in several cases, while differences may be the result of their sexual system – which affects specially the size – and their histology, which is related to the dispersal syndrome. The comparison of our data with previous molecular phylogeny of the section suggests that a significant morphological variation is not associated with significant DNA sequence changes.