Floral Development of Rhamnaceae and Origin of Its Unique Floral Features.

Rhamnaceae flowers have a peculiar morphology, including keeled sepals, one stamen whorl closely related to the petals, and a broad perigynous hypanthium that supports a voluminous nectary. In the present investigation, we detailed the flower development of five Rhamnaceae species to understand the origin of such specific floral characteristics. Floral buds and flowers were processed for surface and histological analyses. The sepals emerge in sequential order and the other organs in simultaneous order. The development of the perigynous hypanthium renders the floral apex broad and concave. The sepals undergo abaxial thickening early on, forming a keel and strongly influencing the floral merosity. Petals and stamens appear close to each other on the same radius in a very short plastochron. The carpels unite soon after their emergence, forming a syncarpous ovary and free style branches. Differences in intercalary carpel growth promote the formation of inferior (Gouania virgata) and semi-inferior ovaries (Colubrina glandulosa, Hovenia dulcis, and Sarcomphalus joazeiro). Rhamnidium elaeocarpum does not undergo such growth, and the resulting ovary is superior. The keeled sepals promote the isolation of the petal-stamen pair inside the flower bud. The possibility of a common primordium that the originates petal and stamen is refuted. Comparisons with other Rosales families provide insights into the floral origin and diversification of Rhamnaceae.

Exploring the diversity of andean berries from northern Peru based on molecular analyses.

More than 12,000 species have been listed under the category of berries, and most of them belong to the orders Ericales and Rosales. Recent phylogenetic studies using molecular data have revealed disagreements with morphological approaches mainly due to diverse floral arrangements, which has proven to be a problem when recognizing species. Therefore, the use of multilocus sequence data is essential to establish robust species boundaries. Although berries are common in Andean cloud forests, diversity of these taxa has not been extensively evaluated in the current context of DNA-based techniques. In this regard, this study characterized morphologically and constructed multilocus phylogenies using four molecular markers, two chloroplast markers (matK and rbcL) and two nuclear markers (ITS and GBSSI-2). Specimens did not show diagnostic features to delimit species of berries. A total of 125 DNA-barcodes of andean berries were newly generated for the four molecular markers. The multilocus phylogenies constructed from these markers allowed the identification of 24 species grouped into the order Ericales (Cavendishia = 1, Clethra = 2, Disterigma = 2, Gaultheria = 4, Thibaudia = 4, Vaccinium = 3) and Rosales (Rubus = 8), incorporating into the Peruvian flora four new records (Disterigma ecuadorense, Disterigma synanthum, Vaccinium meridionale and Rubus glabratus) and revealing the genus Rubus as the most diverse group of berries in the Amazonas region. The results of this study showed congruence in all the multilocus phylogenies, with internal transcribed spacer (ITS) showing the best resolution to distinguish the species. These species were found in coniferous forests, dry and humid forests, rocky slopes, and grasslands at 2,506-3,019 masl from Amazonas region. The integration of morphological and DNA-based methods is recommended to understand the diversity of berries along the Peruvian Andean cloud forest. Abstract in Quechua language Qhawarqan astawan chunka iskayniyuq waranqa especiekuna bayasmanta huch'uy mit'a maypichus hatun rak'i chayaqi ordenkunata Ericaleswan Rosaleswan. Chayraqpi Khuski filogeneticamanta rurachiy allincharqan chanikuna molecularkuna willarqan ayñi rikunawanta morfologicokunamanta, qaylla llapan rantichay t'ika tiktutaywan ñawray, ima kay kaqta qhawacgirqan kay huk champay pachaman riqsiypa especiekunamanta. Hina kaqtintaq, chanikuna qatikipaykunamanta multilocus hat'alliy tiksipmi takyachiypaq saywakuna sinchikuna especiekunamanta. Pana bayaskuna kanku allatinkuna sach'a-sach'api phuyusqa anti runap, ñawran manan karqan achka kamaykuy kunan pacha allwiyaraykupi takyasqakuna ADN. Chayrayku, Noqanchispa taqwi allincharqan huk filogenia multilocus, rarachikupúnmi tawa molecular marcadorkuna, caspa iskay markadorkunawan cloroplastomanta (matK, rbcL) iskay markadorkunawan nuclearkunamanta (ITS, GBSSI-2). Kaykunawan filogeniamanta huniqamuran kikinchay iskay chunka tawayoq especies ima tantaqamuran q'anchis generospi (Cavendishia=1, Clethra=2, Disterigma=2, Gaultheria=4, Thibaudia=4, Vaccinium=3, Rubus=8), kaykunata huñuyqamuranta piruwanu llacha kamay tawa musuq quillqakamachikuta (Disterigma ecuadorense, Disterigma synanthum, Vaccinium meridionale, Rubus glabratus). Nocaykuq lluqsisqan kuwirinti rikuchirurqan llapankuna filogeniaspi multilocusmanta, kaspa espaciador transcrito interno (ITS) pi rikuchina kutuwi mihur rantichay riqsiypaq especiekunata. Abstract in Awajun language Dekanauwai juú weantug 12000 sag nagkaikiut, júna nejég tente ainawai nuintushkam kuashtai Ericales nuigtu Rosales weantui. Molecularesjai takasmaug juki filogeneticos augtus yamá dekai antugnaiñasmauwa nuna Morfologicosjai disa umikmaug, juka waignawai kuashag yagkunum, juwai dekaata tamanum kuashat utugchata ama nunuka. Nunui asamtai multilocus takasmauwa nujai dekanui wajukut ainawa pipish tumaig aidaush. Tujashkam kuashtai tentee nejég ainaug ikam naig yujagkim amuamua nunuig, wajupá kuashtakit tusajig ashi dekapasjig ADNjain dischamui. Nuni tamaugmak, ii augtusag duka takasé filogenia multilocus dekamua nujai, takasji ipák usumat marcadores molecularesjai, jimag marcadores cloroplastosjai (matK nuigtu rbcL) nuigtu jimag marcadores nuclearesjai (ITS nuigtu GBSSI-2). Juu filogenias dekaji 24 sag nagkaikiut tuwaka 7 generosnug tuwaka awa nunu (Cavendishia=1, Clethra=2, Disterigma=2, Gaultheria=4, Thibaudia=4, Vaccinium=3, Rubus=8), juui dekanai yamajam ipák usumat ajag perunum awanunu (Disterigma ecuadorense, Disterigma synanthum, Vaccinium meridionale nuigtu Rubus glabratus).

Uncovering the Neglected Floral Secretory Structures of Rhamnaceae and Their Functional and Systematic Significance.

Rhamnaceae flowers are notably recognized by their fleshy nectary. Other types of floral secretory structures have been scarcely reported for this family. Thus, the objective of the present study was to update the occurrence of these structures in the family and to contribute to the knowledge of their morphology and systematic significance. To this end, we carried out an extensive bibliographic search on the secretory structures of the family and obtained data for 257 taxa. Additionally, we presented here novel data (surface, anatomy, and ultrastructure) for six species belonging to the main clades within Rhamnaceae. The family has a wide diversity of types of mucilage-secreting structures: epidermis, hypodermis, idioblasts, cavities, and ducts. Mucilage and phenolic idioblasts are widely distributed among the floral organs. Colleters are present in all sampled species, and these are the first reports of their occurrence in floral organs of Rhamnaceae. The information obtained about the structure, secreted content, and occurrence of the secretory structures of Rhamnaceae helped us to understand the assertive folk use of its species. The absence of mucilage and the presence of resin or mucilage cavities and ducts in some taxa may have intrafamily systematic significance.

Anatomy solves the puzzle of explosive pollen release in wind-pollinated urticalean rosids.

PREMISE OF THE STUDY: This study details the unusual synorganization of the staminate flower in wind-pollinated urticalean rosids to add the missing pieces that complete the puzzle of the explosive mechanism of pollen release in this group. METHODS: Flower buds and flowers were analyzed using light and scanning electron microscopy. KEY RESULTS: The pistillode, stamens, and sepals form a floral apparatus that explosively releases pollen to be carried by the wind. The anthers dehisce when the stamens are still inflexed on the floral bud and are enveloped by the sepals and supported by an inflated pistillode. The distension of the filaments presses the pistillode, which decreases the pressure exerted on the anthers by releasing the air accumulated internally through its apical orifice. The extended filaments and the dehiscent free anthers move rapidly outward from the center of the flower. This movement of the filaments is then blocked by the robust basally united sepals, which causes a rapid inversion of the anther position, thus hurling the pollen grains far from the flower. The pollen grains are released grouped by the mucilage produced in high quantity in the cells found in all floral organs. CONCLUSIONS: The anatomical structure of the pistillode and the finding of mucilaginous cells are the main features that help in the understanding the explosive mechanism of pollen release in urticalean rosids. The pistillode can be considered an exaptation because it was evolved later to provide a new role in the plant, optimizing male fitness.

Preliminary studies about the role of physicochemical parameters on the organotin compound dynamic in a South American estuary (Bahía Blanca, Argentina).

This work provides a preliminary study of the destination, mobility, and availability of tributyltin (TBT), dibutyltin (DBT), and monobutyltin (MBT) in contaminated sediments and water column within Puerto Rosales Port, located in the middle zone of the Bahía Blanca Estuary (Argentina). Therefore, this study presents the first comprehensive results of the role of several physicochemical parameters (temperature, pH, Eh, salinity, turbidity, organic matter, chlorophyll, and macronutrients) in behavior of organotin compounds (OTCs) in a marine-coastal ecosystem. The samples were collected seasonally in May, August, and November during 2014. Levels of OTCs were determined in sediments and water column samples by means of gas chromatography-mass spectrometry analysis. Degradation index analyses suggested not recent inputs of TBT at the area of study. However, results submitted a continuous input of TBT into the column water; further, its distribution and degradation pattern were shown to be influenced by salinity, turbidity, particulate organic matter, chlorophyll, and nitrates. These last two parameters, chlorophyll and nitrates, also were very important for sediment samples. Chlorophyll together with high temperatures recorded in the surface sediments triggers biodegradation process of TBT and DBT resulting in high MBT levels while nitrates seemed to promote debutylation process. Furthermore, pH appeared to influence drastically the adsorption/desorption activity of TBT and DBT in sediment. Finally, the Eh obtained suggested a degradation of TBT thanks to the presence of Fe (III) in this compartment. In addition, in fact, the results outlined a possible MBT additional input that contributes to the pollution observed in the study area. Graphical abstract Organotin compounds behavior according to several physicochemical parameters.