Micropropagation of Guarianthe skinneri (Bateman) Dressler & W. E. Higging in Temporary Immersion Bioreactors

Guarianthe skinneri (Bateman) Dressler & W. E. Higgins is an orchid valued for its ornamental characteristics. However, it is an orchid classified as threatened with extinction due to the illegal extraction from its natural habitat. In addition, its propagation through seed germination is very low, as is the case with most members of the family Orchidaceae. Its asexual propagation through pseudobulb separation is slow and produces a few propagules. For this reason, in vitro propagation techniques are an alternative to increase the number of plants obtained and thus be able to recover this valuable plant genetic resource. Temporary immersion systems (TIS) offer the advantage of mass-propagating plants for different purposes. This chapter describes a large-scale micropropagation protocol for Guarianthe skinneri using temporary immersion bioreactors (TIB).

Lead tolerance and accumulation characteristics of Cubana Kordes rose in lead-contaminated soil

This study was conducted to determine lead tolerance and accumulation characteristics of Cubana Kordes rose, which is used in landscaping studies in areas with heavy traffic. In the study, 0%, 3%, and 6% leonardite was added to the sand growing medium, and Pb was applied at different doses (0, 200, 400, 800, and 1600 mg Pb kg^-1). At the end of the experiment, the effect of Pb application on plant physiological properties was not statistically significant. The Pb concentration of flower and stem was between 4.50 and 8.92 mg kg^-1 and 8.47 and 543.25 mg kg^-1, respectively. The Pb concentration in the stem increased with an increase in the dose of Pb. The Pb concentration in the root was between 4.00 and 50.35 mg kg^-1 and increased with an increase in the dose of Pb (p < 0.05). The available Pb concentration in the soil varied between 0.05 and 448.79 mg kg^-1. The transfer factor value varied between 1.84 and 18.73 and the bioaccumulation factor value ranged between 0.00 and 10.46. The amount of Pb removed from the soil by the stem was between 124.7 and 8346.6 µg kg^-1. From the results, we determined that Pb accumulated at a higher rate in the stem than in the root and the flower of Cubana Kordes roses. We found that these roses could tolerate the accumulation of Pb, and hence, they have a great potential to be used in the remediation of soil contaminated by Pb.

Taxonomic revision of the threatened African genus Pseudohydrosme Engl. (Araceae), with P. ebo, a new, critically endangered species from Ebo, Cameroon

This is the first revision in more than 100 years of the African genus Pseudohydrosme, formerly considered endemic to Gabon. Closely related to Anchomanes, Pseudohydrosme is distinct from Anchomanes because of its 2-3-locular ovary (vs. unilocular), peduncle concealed by cataphylls at anthesis and far shorter than the spathe (vs. exposed, far exceeding the spathe), stipitate fruits and viviparous (asexually reproductive) roots (vs. sessile, roots non-viviparous), lack of laticifers (vs. laticifers present) and differences in spadix: spathe proportions and presentation. However, it is possible that a well sampled molecular phylogenetic analysis might show that one of these genera is nested inside the other. In this case the synonymisation of Pseudohydrosme will be required. Three species, one new to science, are recognised, in two sections. Although doubt has previously been cast on the value of recognising Pseudohydrosme buettneri, of Gabon, it is here accepted and maintained as a distinct species in the monotypic section, Zyganthera. However, it is considered to be probably globally extinct. Pseudohydrosme gabunensis, type species of the genus, also Gabonese but probably extending to Congo, is maintained in Sect. Pseudohydrosme together with Pseudohydrosme ebo sp.nov. of the Ebo Forest, Littoral Region, Cameroon, the first addition to the genus since the nineteenth century, and which extends the range of the genus 450 km north from Gabon, into the Cross-Sanaga biogeographic area. The discovery of Pseudohydrosme ebo resulted from a series of surveys for conservation management in Cameroon, and triggered this article. All three species are morphologically characterised, their habitat and biogeography discussed, and their extinction risks are respectively assessed as Critically Endangered (Possibly Extinct), Endangered and Critically Endangered using the IUCN standard. Clearance of forest habitat for logging, followed by agriculture or urbanisation are major threats. Pseudohydrosme gabunensis may occur in a formally protected area and is also cultivated widely but infrequently in Europe, Australia and the USA for its spectacular inflorescences.

Targeted generation of polyploids in Hydrangea macrophylla through cross-based breeding

Background

Up to now, diploid and triploid cultivars were reported for the ornamental crop Hydrangea macrophylla. Especially, the origin of triploids and their crossing behaviors are unknown, but the underlying mechanisms are highly relevant for breeding polyploids.

Results

By screening a cultivar collection, we identified diploid, triploid, tetraploid and even aneuploid H. macrophylla varieties. The pollen viability of triploids and tetraploids was comparable to that of diploids. Systematic crosses with these cultivars resulted in viable diploid, triploid, tetraploid and aneuploid offspring. Interestingly, crosses between diploids produced diploid and 0 or 1–94% triploid offspring, depending on the cultivars used as pollen parent. This finding suggests that specific diploids form unreduced pollen, either at low or high frequencies. In contrast, crosses of triploids with diploids or tetraploids produced many viable aneuploids, whose 2C DNA contents ranged between the parental 2C values. As expected, crosses between diploid and tetraploid individuals generated triploid offspring. Putative tetraploid plants were obtained at low frequencies in crosses between diploids and in interploid crosses of triploids with either diploid or tetraploid plants. The analysis of offspring populations indicated the production of 1n = 2x gametes for tetraploid plants, whereas triploids produced obviously reduced, aneuploid gametes with chromosome numbers ranging between haploid and diploid level. While euploid offspring grew normally, aneuploid plants showed mostly an abnormal development and a huge phenotypic variation within offspring populations, most likely due to the variation in chromosome numbers. Subsequent crosses with putative diploid, triploid and aneuploid offspring plants from interploid crosses resulted in viable offspring and germination rates ranging from 21 to 100%.

Conclusions

The existence of diploids that form unreduced pollen and of tetraploids allows the targeted breeding of polyploid H. macrophylla. Different ploidy levels can be addressed by combining the appropriate crossing partners. In contrast to artificial polyploidization, cross-based polyploidization is easy, cheap and results in genetically variable offspring that allows the direct selection of more robust and stress tolerant polyploid varieties. Furthermore, the generation of polyploid H. macrophylla plants will favor interspecific breeding programs within the genus Hydrangea.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12863-020-00954-z.

Converting treatment wetlands into "treatment gardens": Use of ornamental plants for greywater treatment

Nowadays, the use of constructed wetlands for on-site greywater treatment is a very promising option. The successful application of this nature-based solution at full scale requires public acceptance, economic feasibility and the production of high-quality treated greywater. This work focuses on the use of ornamental plants as vertical flow constructed wetland (VFCW) vegetation for greywater treatment, aiming to improve aesthetic and acceptability of the system. The performance and economic feasibility of the proposed green technology were examined during a 2-years study. Results show that Pittosporum tobira and Hedera helix can grow in VFCW operating with greywater without any visible symptoms. These species tolerated both drought and flooding conditions, making them ideal for use not only in residential buildings but also in seasonal hotels and holiday homes. In contrast, partial defoliation of Polygala myrtifolia plants was observed during the winter period. High average removal efficiencies were observed for BOD (99%), COD (96%) and TSS (94%) in all examined VFCWs including unplanted beds. Phosphorus removal gradually decreased from 100% during first months of operation to 15% during second year of operation. In addition, total coliforms concentration reduced by 2.2 log units in the effluent of all planted systems, while lower removal efficiency was observed in the absence of plants. The mean concentration of BOD and TSS in the treated greywater met the standards for indoor reuse (<10 mg/L). Cost payback periods for the installation of the proposed technology in a multi-family building, a single house and a hotel in Greece were found 4.7, 16.6 and 2.5 years, respectively. Overall, the "treatment gardens" proposed in this study provide a technically and economically feasible solution for greywater treatment, with the additional benefit of improving the aesthetic of urban, semi-urban and touristic areas.

Micropropagation of Guarianthe skinneri (Bateman) Dressler et W. E. Higging in Temporary Immersion Systems

This study's aim was to establish a protocol for the micropropagation of G. skinneri using temporary immersion system (TIS). Different concentrations of 6-Benzylaminopurine (0, 1, 2, and 3 mg L^-1), three different systems of cultivate semi-solid (SS) and liquid media under partial (PI) and temporary immersion systems (TIS), different compositions of the inorganic salts, and the number of subcultures were evaluated. The results showed a maximum of 16.56 shoots per explant obtained through TIS, adjusting all the parameters evaluated in our study. One higher number of shoots per explant was observed in the micropropagation of G. skinneri TIS compared to SS and PI. While the use of 3 mg L^-1 of BAP + MS (Murashige and Skoog) media was better than 3 mg L^-1 of BAP VW (Vacint and Went) for the generation of a greater number of shoots per explant, 6.33 and 2.72, respectively. The immersion frequency of 2 min every 4 h allowed the production to be scaled to 8.54 shoots per explant. While it was necessary to perform three subcultures every 30 days, to obtain 16.56 shoots per explant, a rooting phase was not required due to the generation of adventitious roots during the different subcultures. However, a phase of elongation of the regenerated plants with ½ MS + GA3 (gibberellic acid) was needed to guarantee 100% survival in the process of acclimatization. In conclusion, this plant production system can be applied for the commercial micropropagation of this species for ornamental purposes, as well as for its reintroduction in protected natural areas.

In vitro regeneration approaches for restoration of Ceropegia mohanramii-an endemic and critically endangered asclepiad

The study aimed to develop an efficient, rapid, and large-scale in vitro regeneration system for propagation, conservation, and restoration of an endemic and critically endangered herb, Ceropegia mohanramii. The cultures were established using nodal explants on Murashige and Skoog's (MS) medium supplemented with 6-benzylaminopurine (BAP: 1.0 mg/l). Nodal buds cultured on MS medium supplemented with BAP (2.0 mg/l) along with indole-3-butyric acid (IBA, 0.5 mg/l) resulted with production of maximum number of shoots (17.1 ± 1.2) in hundred percent of the cultures. MS medium supplemented with BAP (2.0 mg/l) along with diverse concentrations of indole-3acetic acid (IAA) promoted the in vitro flowering. In vitro regenerated shoots were transferred to one-half MS medium fortified with singular supplementation of auxins, where IBA (1.5 mg/l) served optimal for production of maximum number of roots (5.7 ± 0.6). In vitro derived plantlets were hardened under controlled conditions in a glasshouse and subsequently transferred to soil. Over 1200 saplings were transplanted to eight different localities of the Western Ghats where over 76% survival is recorded after 1 year of transplantation.

Rapid identification of inflorescence type markers by genotyping-by-sequencing of diploid and triploid F1 plants of Hydrangea macrophylla

Background

The ornamental crop Hydrangea macrophylla develops highly attractive lacecap (wild type) or mophead inflorescences. The mophead trait, which is mostly favored by consumers, is recessively inherited by the INFLORESCENCE TYPE locus (INF). If lacecap cultivars are crossed with mophead cultivars, then either 50% or all progenies develop lacecap inflorescences, depending on the zygosity at the INF locus. For most cultivars, the zygosity at the INF locus is unknown. Furthermore, the determination of the inflorescence type in offspring populations is time-consuming, because seedlings flower the first time in the 2nd year after sowing. Within this study, we aimed to develop DNA-based markers that allow to determine the zygosity at the INF locus of prospective parental plants and to predict the inflorescence phenotype of seedlings already in the non-flowering stage.

Results

By crossing a mophead and a lacecap cultivar of H. macrophylla, we produced a pseudo-backcross F₁ population consisting of 422 plants. These plants segregated into 279 lacecap, 73 mophead, 3 intermediate and 67 non-flowering plants, differing significantly from the expected 1:1 segregation ratio. Surprisingly, 75% of these plants were triploid, although both parents were diploid. We found that the lacecap parent produced unreduced pollen, which induced the formation of triploids. 380 randomly selected F₁ plants were genotyped by genotyping-by-sequencing (GbS). Using a genome assembly of cultivar ‘Sir Joseph Banks’, we performed subsequently a bulk sequence analysis with pooled GbS data of diploid versus mophead plants. We identified directly 2 markers tightly linked with the INF locus, each of them explaining 99.7% of the inflorescence phenotype. Using a collection consisting of 56 diploid, triploid or tetraploid H. macrophylla varieties, we detected 6 sequence variants for one of these markers. Two variants were associated with the mophead phenotype. Furthermore, we found by marker analysis a co-segregation between the mophead and the non-flowering trait, which indicates a major flowering time locus next to the INF locus.

Conclusion

Through bulk sequence analysis of pooled GbS data from diploid and polyploid F₁ plants, we identify rapidly tightly linked markers for the inflorescence type, a dominant-recessively inherited trait in the non-model plant species H. macrophylla.

Electronic supplementary material

The online version of this article (10.1186/s12863-019-0764-6) contains supplementary material, which is available to authorized users.

Species richness of riparian vegetation after three decades of Kenyir dam establishment

This data article is on riparian vegetation species richness in four different streams located in the Sultan Mahmud Hydroelectric dam, also known as Kenyir dam and commonly referred to as Tasik Kenyir, Terengganu. The dataset consists of three reservoir-island streams and the other is a small stream located on the mainland. A total of 41 families and 90 species of riparian plants were reported for the first time after 34 years of the establishment of the Sultan Mahmud Hydroelectric dam. Trees contributing 60% of the species recorded in this study and the others were non-tree species, including climbers, ferns, epiphyte, herbs, shrub, strangling trees and palms. Among the recorded riparian plant species, two are introduced which are Clidemia hirta and Mimosa pigra. The highest diversity of riparian plant found in the stream of Sungai Kiang, followed by Sungai Ikan and Sungai Saok with 46, 29 and 17 species respectively for the reservoir-island streams. The mainland stream, Sungai Siput recorded 37 species. These riparian plants provide important ecosystem services, among others soil stabilization, habitat and food for aquatic fauna and water filtration. In terms of plant utilization potential and values, 47 species are identified having medicinal value, 10 species with ornamental value and another 36 species are timber trees. Our study demonstrates that the riparian plants are closely linked to stream size with variability associated with types of stream systems. The data collected also demonstrates that the riparian plant community is at the seral stages of riparian forest. This is indicated by the increase in plant species richness as the vegetation gradually changes from riparian towards mature forest composition. To secure ecological functions of Tasik Kenyir riparian plant assemblages, particularly in stabilizing the lake's margin and riverbank, it is recommended that monitoring and legal protection may need to be imposed by local authority.

(Cnidaria: Myxosporea), a parasite of the Amazonian ornamental fish Hyphessobrycon loretoensis from Peru: A myxosporean dispersal approach

Myxosporean are endoparasitic cnidarians of wide distribution and responsible for important economic losses in fisheries and aquaculture. A new myxosporean species, Henneguya peruviensis n. sp., is herein described as obtained from the gill filaments of Hyphessobrycon loretoensis caught in the Nanay River, Department of Loreto, Peru. The parasite was found in 37 of 45 (82.2%) examined H. loretoensis. The new species was characterized based on morphological features and 18S rDNA gene sequence data. The sequencing of the 18S rDNA gene from the spores of H. peruviensis n. sp. resulted in 1632 nucleotides and this sequence did not match any of the myxozoan available in the GenBank. Phylogenetic analysis showed that H. peruviensis n. sp. closed together with H. leporinicola. Nonetheless, the 18S rDNA sequences of H. peruviensis n. sp. and H. leporinicola have only 82% similarity. This is the first description and molecular study of a Myxozoa parasitizing fish of the genus Hyphessobrycon in the Amazon basin. Given the importance of the ornamental fish industry in translocation of aquatic organisms worldwide, the international movement of myxosporeans in infected fish is discussed in terms of disease outbreaks and the need for preventative action.

Diversity of plant defense elicitor peptides within the Rosaceae

BACKGROUND

Plant elicitor peptides (Peps) are endogenous molecules that induce and amplify the first line of inducible plant defense, known as pattern-triggered immunity, contributing to protect plants against attack by bacteria, fungi and herbivores. Pep topic application and transgenic expression have been found to enhance disease resistance in a small number of model plant-pathogen systems. The action of Peps relies on perception by specific receptors, so displaying a family-specific activity. Recently, the presence and activity of Peps within the Rosaceae has been demonstrated. Here we characterized the population of Pep sequences within the economically important plant family of Rosaceae, with special emphasis on the Amygdaleae and Pyreae tribes, which include the most relevant edible species such as apple, pear and peach, and numerous ornamental and wild species (e.g. photinia, firethorn and hawthorn).

RESULTS

The systematic experimental search for Pep and the corresponding precursor PROPEP sequences within 36 Amygdaleae and Pyreae species, and 100 cultivars had a highly homogeneous pattern, with two tribe-specific Pep types per plant, i.e. Pep1 and Pep2 (Amygdaleae) or Pep3 and Pep4 (Pyreae). Pep2 and Pep3 are highly conserved, reaching identity percentages similar to those of genes used in plant phylogenetic analyses, while Pep1 and Pep4 are somewhat more variable, with similar values to the corresponding PROPEPs. In contrast to Pep3 and Pep4, Pep1 and Pep2 sequences of different species paralleled their phylogenetic relationships, and putative ancestor sequences were identified. The large amount of sequences allowed refining of a C-terminal consensus sequence that would support the protective activity of Pep1-4 in a Prunus spp. and Xanthomonas arboricola pv. pruni system. Moreover, tribe-specific consensus sequences were deduced at the center and C-terminal regions of Peps, which might explain the higher protection efficiencies described upon topic treatments with Peps from the same tribe.

CONCLUSIONS

The present study substantially enhances the knowledge on Peps within the Amygdaleae and Pyreae species. It can be the basis to design and fine-tune new control tools against important plant pathogens affecting Prunus, Pyrus and Malus species.

Bipolaris marantae sp. nov., A Novel Helminthosporoid Species Causing Foliage Blight of the Garden Plant Maranta leuconeura in Brazil

A severe leaf spot, turning to foliage blight, was observed on leaves of Maranta leuconeura growing in a garden in Brazil (state of Rio de Janeiro) in 2015. A dematiaceous hyphomycete bearing a morphology typical of a helminthosporoid fungi was regularly found in association with diseased tissues. The fungus was isolated and pathogenicity was demonstrated through the completion of Koch's postulates. A morphology and molecular analysis led to the conclusion that the fungus belonged to the genus Bipolaris, which is characterized by having fusiform conidia, externally thickened and truncate hila and a bipolar pattern of germination. Additionally, homology of internal transcribed spacer and GAPDH sequences with sequences of other Bipolaris species, confirmed its generic placement. A phylogenetic study also indicated clearly that the fungus on M. leuconeura is phylogenetically distinct from related species of this genus, leading to the proposal of the new species Bipolaris marantae.

Pathogenesis of mixed infection by Spironucleus sp. and Citrobacter freundii in freshwater angelfish Pterophyllum scalare

The present study was carried out to identify and describe the pathology of the freshwater angelfish Pterophyllum scalare during chronic mortality in an in-door aquaculture system. Scraping of the integument and gills and the collection of intestinal contents to search for external and internal parasites were performed. Kidneys were collected aseptically for the microbiological analysis and the isolates were subjected to antibiotics to test for susceptibility. Subsequently, necropsy for macroscopic assessment and collection of internal organs for histopathology were performed. The fish exhibited lethargy, lip tumor, hemorrhage and liver granuloma. No ectoparasites were diagnosed. Endoparasites of the genus Spironucleus were found in large numbers in the intestine of the affected fish. In the microbiological analysis, Citrobacter freundii was isolated from the kidney and identified by colony PCR. This bacterium showed susceptibility to three of the eight antibiotics evaluated: ciprofloxacin, cefoxitin and tetracycline. For the pathological analysis, liver and spleen granulomas were present. In the intestinal tissue, a large and unusual amount of mast cells and their free granules were described and discussed in detail. The present study showed that mast cells play an important role during the chronic infection of freshwater angelfish.

Use of propofol as an anesthetic and its efficacy on some hematological values of ornamental fish Carassius auratus

The aim of this study was to determine the level of anesthesia attained in Carassius auratus using a propofol bath administration and using values of haematological profile of blood and examinations, to assess the effects of the fish exposure to that anaesthetic. Acute toxicity values of propofol for gold fish were found 96 h LC50 6.353 mg/L, 96 h LC1 2.966 mg/L and 96 h LC99 13.609 mg/L. Time to induce anesthesia in propofol experiment was significantly higher than Clove oil (p < 0.05), but there was no significant difference in recovery time between the experiments. No significant decrease was found in Total RBC, WBC, HCT, MCH, MCV and leukogram indices (p > 0.05). MCHC (%) level of propofol experiment (13.93 ± 1.36) showed significant (p < 0.05) decrease than Clove oil anesthesia (94.95 ± 24.50) and control (62.46 ± 21.90). Hb(g/dl) content (5.20 ± 0.73) showed decrease in propofol exposure compared with control (15.41 ± 4.76) and clove oil experiment (25.39 ± 5.73) (p < 0.05).

Changes of bacterioplankton apparent species richness in two ornamental fish aquaria

We analysed the 16S rRNA gene diversity within the bacterioplankton community in the water column of the ornamental fish Pterophyllum scalare and Archocentrus nigrofasciatus aquaria during a 60-day growth experiment in order to detect any dominant bacterial species and their possible association with the rearing organisms. The basic physical and chemical parameters remained stable but the bacterial community at 0, 30 and 60 days showed marked differences in bacterial cell abundance and diversity. We found high species richness but no dominant phylotypes were detected. Only few of the phylotypes were found in more than one time point per treatment and always with low relative abundance. The majority of the common phylotypes belonged to the Proteobacteria phylum and were closely related to Acinetobacter junii, Pseudomonas sp., Nevskia ramosa, Vogesella perlucida, Chitinomonas taiwanensis, Acidovorax sp., Pelomonas saccharophila and the rest belonged to the α-Proteobacteria, Bacteroidetes, Actinobacteria, candidate division OP11 and one unaffiliated group. Several of these phylotypes were closely related to known taxa including Sphingopyxis chilensis, Flexibacter aurantiacus subsp. excathedrus and Mycobacterium sp. Despite the high phylogenetic diversity most of the inferred ecophysiological roles of the found phylotypes are related to nitrogen metabolism, a key process for fish aquaria.