Assessment of violet-blue color formation in Phalaenopsis orchids.

BACKGROUND: Phalaenopsis represents an important cash crop worldwide. Abundant flower colors observed in Phalaenopsis orchids range from red-purple, purple, purple-violet, violet, and violet-blue. However, violet-blue orchids are less bred than are those of other colors. Anthocyanin, vacuolar pH and metal ions are three major factors influencing flower color. This study aimed to identify the factors causing the violet-blue color in Phalaenopsis flowers and to analyze whether delphinidin accumulation and blue pigmentation formation can be achieved by transient overexpression of heterologous F3'5'H in Phalaenopsis. RESULTS: Cyanidin-based anthocyanin was highly accumulated in Phalaenopsis flowers with red-purple, purple, purple-violet, and violet to violet-blue color, but no true-blue color and no delphinidin was detected. Concomitantly, the expression of PeF3'H (Phalaenopsis equestrsis) was high, but that of PhF3'5'H (Phalaenopsis hybrid) was low or absent in various-colored Phalaenopsis flowers. Transient overexpression of DgF3'5'H (Delphinium grandiflorum) and PeMYB2 in a white Phalaenopsis cultivar resulted a 53.6% delphinidin accumulation and a novel blue color formation. In contrast, transient overexpression of both PhF3'5'H and PeMYB2 did not lead to delphinidin accumulation. Sequence analysis showed that the substrate recognition site 6 (SRS6) of PhF3'5'H was consistently different from DgF3'5'Hs at positions 5, 8 and 10. Prediction of molecular docking of the substrates showed a contrary binding direction of aromatic rings (B-ring) with the SRS6 domain of DgF3'5'H and PhF3'5'H. In addition, the pH values of violet-blue and purple Phalaenopsis flowers ranged from 5.33 to 5.54 and 4.77 to 5.04, respectively. Furthermore, the molar ratio of metal ions (including Al3+, Ca2+ and Fe3+) to anthocyanin in violet-blue color Phalaenopsis was 190-, 49-, and 51-fold higher, respectively, than those in purple-color Phalaenopsis. CONCLUSION: Cyanidin-based anthocyanin was detected in violet-blue color Phalaenopsis and was concomitant with a high pH value and high molar ratio of Al3+, Ca2+ and Fe3+ to anthocyanin content. Enhanced expression of delphinidin is needed to produce true-blue Phalaenopsis.

Ex situ germination as a method for seed viability assessment in a peatland orchid, Platanthera blephariglottis.

UNLABELLED: • PREMISE OF THE STUDY: Assessing seed quality in orchids has been hindered by stringent germination requirements. Seed quality has traditionally been assessed in orchids using in vitro or in situ germination protocols or viability staining. However, these methods are not always well suited for rapid assessment of viability in the context of ecological studies.• METHODS: The potential of an ex situ protocol for seed viability assessment of orchids in ecological studies was investigated by sowing seeds of Platanthera blephariglottis on Sphagnum moss collected in the orchid's natural habitat. Ex situ germination results were compared with those obtained by viability staining using triphenyltetrazolium chloride (TTC), and the effect of seed testa color on staining and germination results was investigated.• KEY RESULTS: The ex situ protocol yielded high germination rates, with 66% of the seeds germinating after 9 wk. Depending on the seed testa color class, ex situ germination rates were about 1.4 to 2.5 times higher than viability rates determined using TTC, indicating that the TTC technique underestimated viability compared with the method using ex situ germination. The TTC estimates of viability rates were higher for seeds with dark-colored testae than for pale ones, whereas seed testa color had no effect on germination.• CONCLUSIONS: Our study showed promising results for the use of ex situ germination as an alternative to previously developed protocols for seed viability assessment of orchids in ecological studies. Staining using TTC might not be well suited for this purpose, since it introduced a bias with respect to seed testa color.

Considerações sobre a Família Orquidacea: taxonomia, antropismo, valor econômico e tecnologia: [revisão] / Considerations on the Family Orchidaceae: taxonomy, anthropism, economic value and technology: [revision] / Consideraciones acerca de la Familia Orchidaceae: taxonomía, antropismo, valor económico y tecnología: [revisión]

O presente trabalho tem como finalidade divulgar o estado da arte das Orquidacea e discorrer sobre a sua sistemática evolutiva, antropismo e valor econômico. O trabalho teve como base uma cuidadosa revisão bibliográfica, bem como a análise da coleção do Orquidário do Estado de São Paulo e exsicatas do herbário “Maria Eneyda P. K. Fidalgo”, do Instituto de Botânica do Estado de São Paulo, provenientes de todo o Brasil.

The present work aims to present the state-of-the-art of Orchidaceae and discuss its evolutive systematic, anthropism and economical value. The work took as its bases a careful bibliographical survey as well as the analysis of the collection of the Orchidarium of Sao Paulo State and exsiccates of the herbarium “Maria Eneyda P. K. Nobleman”, of the Institute of Botany of Sao Paulo State, comingfrom all parts of Brazil.

Este trabajo pretende presentar el actual nivel de conocimiento de las Orchidaceae y hablar de su sistemática evolutiva, antropismo y valor económico. El trabajo tomó como sus bases una revisión bibliográfica cuidadosa así como el análisis de la colección del Orchidarium del estado de São Paulo y exsicatos del herbario “Maria Eneyda P. K. Nobleman”, del Instituto de Botánica del Estado de São Paulo, que viene de todas las partes de Brasil.

Considerações sobre a Família Orquidacea: taxonomia, antropismo, valor econômico e tecnologia / Consideraciones acerca de la Familia Orchidaceae: taxonomía, antropismo, valor económico y tecnología / Considerations on the Family Orchidaceae: taxonomy, anthropism, economic value and technology

O presente trabalho tem como finalidade divulgar o estado da arte das Orquidacea e discorrer sobre a sua sistemática evolutiva, antropismo e valor econômico. O trabalho teve como base uma cuidadosa revisão bibliográfica, bem como a análise da coleção do Orquidário do Estado de São Paulo e exsicatas do herbário “Maria Eneyda P. K. Fidalgo”, do Instituto de Botânica do Estado de São Paulo, provenientes de todo o Brasil. Palavras-chave: Biodiversidade. Orchidaceae-crescimento & desenvolvimento. Orchidaceae-taxonomia(AU).

The present work aims to present the state-of-the-art of Orchidaceae and discuss its evolutive systematic, anthropism and economical value. The work took as its bases a careful bibliographical survey as well as the analysis of the collection of the Orchidarium of Sao Paulo State and exsiccates of the herbarium “Maria Eneyda P. K. Nobleman”, of the Institute of Botany of Sao Paulo State, comingfrom all parts of Brazil. Keywords: Biodiversity. Orchidaceae-growth & development. Orchidaceae-taxonomy(AU).

Este trabajo pretende presentar el actual nivel de conocimiento de las Orchidaceae y hablar de su sistemática evolutiva, antropismo y valor económico. El trabajo tomó como sus bases una revisión bibliográfica cuidadosa así como el análisis de la colección del Orchidarium del estado de São Paulo y exsicatos del herbario “Maria Eneyda P. K. Nobleman”, del Instituto de Botánica del Estado de São Paulo, que viene de todas las partes de Brasil. Palabras llave: Biodiversidad. Orchidaceae-crecimiento & desarrollo. Orchidaceae-taxonomia(AU).

Is floral longevity influenced by reproductive costs and pollination success in Cohniella ascendens (Orchidaceae)?

BACKGROUND AND AIMS: Although studies have shown that pollen addition and/or removal decreases floral longevity, less attention has been paid to the relationship between reproductive costs and floral longevity. In addition, the influence of reproductive costs on floral longevity responses to pollen addition and/or removal has not yet been evaluated. Here, the orchid Cohniella ascendens is used to answer the following questions. (a) Does experimental removal of flower buds in C. ascendens increase flower longevity? (b) Does pollen addition and/or removal decrease floral longevity, and does this response depend on plant reproductive resource status? METHODS: To study the effect of reproductive costs on floral longevity 21 plants were selected from which we removed 50 % of the developing flower buds on a marked inflorescence. Another 21 plants were not manipulated (controls). One month later, one of four flowers on each marked inflorescence received one of the following pollen manipulation treatments: control, pollinia removal, pollination without pollinia removal or pollination with pollinia removal. The response variable measured was the number of days each flower remained open (i.e. longevity). KEY RESULTS: The results showed significant flower bud removal and pollen manipulation effects on floral longevity; the interaction between these two factors was not significant. Flowers on inflorescences with previously removed flower buds remained open significantly longer than flowers on control inflorescences. On the other hand, pollinated flowers closed much faster than control and removed-pollinia flowers, the latter not closing significantly faster than control flowers, although this result was marginal. CONCLUSIONS: The results emphasize the strong relationship between floral longevity and pollination in orchids, as well as the influence of reproductive costs on the former.

Quantifying relative extinction risks and targeting intervention for the orchid flora of a natural park in the European preAlps.

Conservation currently relies largely on hindsight because demographic studies identify population decline after the event. Nevertheless, the degree of aggregation within a population is an "instantaneous" characteristic with the potential to identify populations presently at greatest risk of genetic impoverishment (via Allee effects and in-breeding depression) and local decline. We sought to determine the relative extinction risk for sympatric orchid species throughout Monte Barro natural park (Lecco, Italy), based on an index of dispersion (I) calculated from the size and location of subpopulations (recorded with GPS and mapped with GIS). Three population dispersion types were identified: (1) highly aggregated and locally abundant (large subpopulations restricted to particular sites; e.g., Gymnadenia conopsea [L.] R.Br.; I=54.5); (2) widespread and moderately aggregated (opportunistic throughout the elevational range of the mountain; e.g., Listera ovata[L.] R.Br.; I=18.9); and (3) weakly aggregated and locally rare (small, highly diffuse subpopulations; e.g., endemic Ophrys benacensis [Reisigl] O. & E. Danesch & Ehrend.; I=4.4). Type 1 populations are more likely to respond to in situ intervention, whereas type 2 are relatively invasive species for which conservation intervention is not necessary, and type 3 are rare species that are least likely to respond to habitat management, for which ex situ conservation and population reinforcement would be most appropriate. Although our methodology provides only a "snapshot" of aboveground patterns of population dispersion, it can help target the application of in situ and ex situ conservation activities proactively and is of particular utility for parks for which a rapid assessment of local extinction risks is needed.