Dissertationen zum Thema „Orchid Flora“

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O cultivo comercial de orquídeas é significativo no mundo. Alguns gêneros e espécies nativas do Brasil, como Cattleya, são apreciados e têm elevado valor econômico devido à capacidade de recombinação genética, beleza, forma, tamanho e durabilidade de suas flores. Contudo, muitas dessas espécies e gêneros encontram-se em risco de extinção, o que as torna objeto para diversos estudos. Técnicas biotecnológicas de cultivo in vitro (germinação assimbiótica de sementes e micropropagação) são valiosos instrumentos na obtenção de mudas. Devido à polinização na natureza ser limitada e com baixa probabilidade de germinação, o cultivo in vitro utiliza formulações de meios de cultivo adequados à germinação de sementes e ao crescimento de diferentes espécies, resultando em maiores percentuais de germinação, em comparação com condições naturais. Neste trabalho foi comparada a atuação de diferentes meios de cultivo na germinação e desenvolvimento de Cattleya guttata, C. leopoldii e C. tigrina. Contudo, os resultados obtidos são preliminares e a procura por um meio de cultivo específico para cada espécie, visando crescimento rápido e em quantidade, necessita de continuidade para somente então afirmar com propriedade qual dos protocolos ensaiados é mais adequado a cada espécie. Existem conflitos taxonômicos envolvendo C. guttata, C. tigrina e C. leopoldii. Muitos taxonomistas consideram C. tigrina e também C. 7 leopoldii como sinônimos de C. guttata. O conhecimento relativo à citogenética da família Orchidaceae tem contribuído expressivamente para o entendimento das relações filogenéticas em todos os níveis taxonômicos em diferentes gêneros. Entre as Catleias, estudos cariológicos identificaram indivíduos com 40 até 100 cromossomos, sendo que n = 20 é o número básico mais frequente. Para diagnosticar o número cromossômico das espécies...
The commercial orchids cultive is significant in the world. Some genera and species native to Brazil, as the Cattleya, are appreciated and have high economic value because of the genetic recombination ability, beauty, shape, size and durability of its flowers. However, many of these species and genera are at risk of extinction, making them subject to several studies. Biotechnological techniques of in vitro (asymbiotic seed germination and micropropagation) are valuable tools for seedlings obtainment. Due to pollination in nature be limited and with low germination probability, in vitro cultivation uses suitable formulations of media culture for germination and growth of different species, resulting in higher germination rates compared to natural conditions. In this work we compared the performance of different culture media on germination and development of Cattleya guttata, C. leopoldii and C. tigrina. However the results are preliminary and the search for a specific medium culture for each species, aiming rapid growth in quantity, need continuity to say properly which of the tested protocols is the most suitable to each species. There are taxonomic conflicts involving C. guttata, C. tigrina and C. leopoldii. Many taxonomists consider C. tigrina and also C. leopoldii as synonyms of C. guttata. The knowledge concerning the cytogenetics of the Orchidaceae family has contributed significantly to the understanding of the phylogenetic relationships at all taxonomic levels in different 9 genus. Among Cattleya, karyological studies have identified subjects with 40 to 100 chromosomes, where n = 20 is the most frequent basic number. To diagnose the chromosome number of C. guttata, C. leopoldii and C. tigrina was employed Feulgen method in 8-hydroxyquinoline pre-treated roots. However, cytogenetic studies obtained were not proper enough to say that the three studied species are similar or different from...

Orientador: Darío Abel Palmieri
Banca: Monica Rosa Bertão
Banca: Cristiano Pedroso de Moraes
Resumo: O cultivo comercial de orquídeas é significativo no mundo. Alguns gêneros e espécies nativas do Brasil, como Cattleya, são apreciados e têm elevado valor econômico devido à capacidade de recombinação genética, beleza, forma, tamanho e durabilidade de suas flores. Contudo, muitas dessas espécies e gêneros encontram-se em risco de extinção, o que as torna objeto para diversos estudos. Técnicas biotecnológicas de cultivo in vitro (germinação assimbiótica de sementes e micropropagação) são valiosos instrumentos na obtenção de mudas. Devido à polinização na natureza ser limitada e com baixa probabilidade de germinação, o cultivo in vitro utiliza formulações de meios de cultivo adequados à germinação de sementes e ao crescimento de diferentes espécies, resultando em maiores percentuais de germinação, em comparação com condições naturais. Neste trabalho foi comparada a atuação de diferentes meios de cultivo na germinação e desenvolvimento de Cattleya guttata, C. leopoldii e C. tigrina. Contudo, os resultados obtidos são preliminares e a procura por um meio de cultivo específico para cada espécie, visando crescimento rápido e em quantidade, necessita de continuidade para somente então afirmar com propriedade qual dos protocolos ensaiados é mais adequado a cada espécie. Existem conflitos taxonômicos envolvendo C. guttata, C. tigrina e C. leopoldii. Muitos taxonomistas consideram C. tigrina e também C. 7 leopoldii como sinônimos de C. guttata. O conhecimento relativo à citogenética da família Orchidaceae tem contribuído expressivamente para o entendimento das relações filogenéticas em todos os níveis taxonômicos em diferentes gêneros. Entre as Catleias, estudos cariológicos identificaram indivíduos com 40 até 100 cromossomos, sendo que n = 20 é o número básico mais frequente. Para diagnosticar o número cromossômico das espécies...
Abstract: The commercial orchids cultive is significant in the world. Some genera and species native to Brazil, as the Cattleya, are appreciated and have high economic value because of the genetic recombination ability, beauty, shape, size and durability of its flowers. However, many of these species and genera are at risk of extinction, making them subject to several studies. Biotechnological techniques of in vitro (asymbiotic seed germination and micropropagation) are valuable tools for seedlings obtainment. Due to pollination in nature be limited and with low germination probability, in vitro cultivation uses suitable formulations of media culture for germination and growth of different species, resulting in higher germination rates compared to natural conditions. In this work we compared the performance of different culture media on germination and development of Cattleya guttata, C. leopoldii and C. tigrina. However the results are preliminary and the search for a specific medium culture for each species, aiming rapid growth in quantity, need continuity to say properly which of the tested protocols is the most suitable to each species. There are taxonomic conflicts involving C. guttata, C. tigrina and C. leopoldii. Many taxonomists consider C. tigrina and also C. leopoldii as synonyms of C. guttata. The knowledge concerning the cytogenetics of the Orchidaceae family has contributed significantly to the understanding of the phylogenetic relationships at all taxonomic levels in different 9 genus. Among Cattleya, karyological studies have identified subjects with 40 to 100 chromosomes, where n = 20 is the most frequent basic number. To diagnose the chromosome number of C. guttata, C. leopoldii and C. tigrina was employed Feulgen method in 8-hydroxyquinoline pre-treated roots. However, cytogenetic studies obtained were not proper enough to say that the three studied species are similar or different from...
Mestre

There is considerable evidence that pollinator shifts can explain many differences in flower morphology between closely related plant species, but the extent to which pollinator shifts can explain the maintenance of among-population variation in floral traits within species is poorly known. In this thesis, I combined comparative and experimental approaches to examine the evolution of floral traits in the moth-pollinated orchid Platanthera bifolia. More specifically, I investigated (1) the relationship between flower and pollinator morphology, (2) phenotypic selection on morphology and phenology in populations in contrasting environments, (3) components of prezygotic reproductive isolation among divergent populations, and (4) the adaptive and functional significance of two correlated floral traits. A study of Scandinavian of P. bifolia populations revealed that spur length was positively correlated with proboscis length of local pollinators, which suggests that variation in spur length reflects adaptive evolution in response to geographically variable pollinator-mediated selection. A phenotypic selection study on Öland, SE Sweden, suggested that disruptive selection on spur length contributes to the maintenance of a bimodal distribution of spur length in mixed habitats, but provided very limited evidence of divergent selection on plant morphology and flowering phenology in grassland and woodland habitats. Field experiments revealed strong reproductive isolation between divergent populations on Öland, due to differences in spatial distribution, flowering phenology, and pollinators, and among-population incompatibility. The results suggest that prezygotic reproductive isolation contributes to the maintenance of population differentiation in floral traits in P. bifolia. A field manipulation experiment demonstrated that spur length but not perianth size affects pollination success and seed production. This suggests that among-population differentiation in perianth size may be the result of a genetic correlation with spur length. Taken together, the results of this thesis suggest that pollinator-mediated selection can shape the evolution of intraspecific floral variation.

A key question in biology is how changes in gene function or regulation produce new morphologies during evolution. The nectar spur is an evolutionarily labile structure known to influence speciation in a broad range of angiosperm taxa. Here, the genetic basis of nectar spur development, and the evolution of differences in nectar spur morphology, is investigated in Linaria vulgaris and two closely related species of orchid, the primitively longer-spurred Dactylorhiza fuchsii, and more derived short-spurred D. viridis (Orchidinae, Orchidaceae). Despite considerable morphological and phylogenetic differences, nectar spur ontogeny is fundamentally similar in each of the study species, proceeding from an abaxial bulge formed on the ventral petal relatively late in petal morphogenesis. However, spur development is progenetically curtailed in the short-spurred orchid D. viridis. In each case spur development involves class 1 KNOTTED1-like homeobox (KNOX) proteins. KNOX gene expression is not restricted to the spur-bearing petal, indicating that additional components are required to define nectar spur position, e.g. canonical ABC genes, determinants of floral zygomorphy, and additional (currently unknown) factors. However, constitutive expression of class 1 KNOX proteins in transgenic tobacco produces flowers with ectopic outgrowths on the petals, indicating that KNOX proteins alone are, to some degree, capable of inducing structures similar to nectar spurs in a heterologous host. Interestingly, KNOX gene expression is high in the ovary of all study taxa, suggesting that KNOX proteins may also have been involved in the evolution of this key angiosperm feature. Although principally involved in maintaining indeterminacy in the shoot apical meristem (SAM), members of the KNOX gene family have been co-opted in the evolution and development of compound leaves where they suppress differentiation and extend the morphogenetic potential of the leaf. A similar model is presented here to explain the role of KNOX proteins in nectar spur development. Co-option of KNOX gene expression to the maturing perianth delays cellular differentiation, facilitating the development of the nectar spur but requiring additional, unknown factors, to determine nectar spur fate. As facilitators of nectar spur development, changes in the spatio-temporal patterns of KNOX gene expression may alter the potential for nectar spur development and explain the critical length differences observed between the orchids D. fuchsii and D. viridis (and among other angiosperm taxa). Taken together, the available data indicate that KNOX genes confer a meristematic state upon plant tissues in a variety of morphogenetic contexts, making the gene family a potentially versatile tool to mediate a wide variety of evolutionary transformations.

Orientador: Marlies Sazima
Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia
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Resumo: Neste trabalho foi realizada a revisão taxonômica, o estudo químico e micromorfológico das ceras epicuticulares, bem como estudados os processos de polinização e os polinizadores de representantes sul-americanos do gênero Cleistes. Foi, também, elaborada uma hipótese filogenética da subtribo Pogoniinae com base em caracteres morfológicos e moleculares, através do seqüenciamento das regiões ITS (nrDNA), e rps16 e trnL-F (cpDNA). O gênero Cleistes apresenta 17 espécies distribuídas entre as Américas Central e do Sul, ocorrendo principalmente em regiões de cerrado do Brasil central. Três dessas espécies foram descritas durante a elaboração do presente trabalho e estão aqui apresentadas. Através do estudo da hipótese filogenética de Pogoniinae foi verificado que essa subtribo apresenta dois clados bem sustentados. Um clado é norte-americano-asiático, e inclui os gêneros Pogonia, Isotria e as espécies norte-americanas de Cleistes. O outro é centro-sul-americano e inclui as espécies de Cleistes distribuídas entre as Américas Central e do Sul. Com o desenvolvimento do presente estudo, incluindo a maioria das espécies de Cleistes nas análises, pode ser demonstrado que esse gênero é parafilético, concordando com os dados publicados por Cameron & Chase (1999). As espécies norte-americanas de Cleistes estão mais relacionadas com os gêneros norte-americano-asiáticos Isotria e Pogonia do que com as espécies centro-sul-americanas de Cleistes. A subtribo Pogoniinae também é parafilética. O saprofítico gênero Pogoniopsis está mais relacionado com representantes dos gêneros Galeola e Cyrtosia (Galeolinae) do que com os demais gêneros pertencentes à subtribo Pogoniinae. Duckeella, um gênero endêmico da Amazônia e irmão das Pogoniinae, não apresenta os caracteres sinapomórficos que define essa subtribo, devendo ser transferido para a subtribo Duckeellinae. Espécies de Cleistes apresentam micromorfologia das ceras epicuticulares existentes nas folhas variando desde lisas, com grânulos, ou até formando placas. As ceras epicuticulares de Cleistes são constituídas principalmente por álcoois, ácidos e ésteres. A composição química das ceras epicuticulares das folhas de espécies de Cleistes é muito variável entre espécies, podendo ser usada na delimitação específica dentro do gênero. Espécies de Cleistes, assim como as demais Pogoniinae, são polinizadas principalmente por abelhas, embora C. libonii apresente beija-flores do gênero Phaethornis como co-polinizadores. Espécies sul-americanas de Cleistes apresentam picos de floração, em que todos os botões maduros de cada planta abrem simultaneamente no mesmo dia. As flores das espécies estudadas são pouco duráveis (geralmente um dia), e oferecem néctar aos polinizadores. O néctar é produzido em nectários glandulares da base do labelo das flores. Para os gêneros norte-americano-asiáticos esses nectários estão ausentes e as abelhas são atraídas às flores por engano. Esse estudo sustenta a hipótese de evolução de flores de engano para flores de néctar
Abstract: The taxonomic revision, the micromorphological and chemical study of the epicuticular waxes, as well as the pollination processes and pollinators of the genus Cleistes were reported. A phylogenetic inference within Cleistes and among genera of subtribe Pogoniinae was also established, based on morphology and nrDNA (ITS) and cpDNA (trnL-F and rps16) sequence data, and using maximum parsimony. The genus Cleistes includes 17 species distributed among Central and South America, occurring mainly in ¿cerrado¿ areas of Central Brazil. Three of these species are new and were described in the present study. The phylogenetic study of Pogoniinae showed that this subtribe presents two well-supported clades. One clade is North-American-Asiatic and includes the genera Isotria, Pogonia and the North-American species of Cleistes. The other clade is Central-South-American and includes the species of Cleistes occurring in Central and South America. The genus Cleistes, in agreement to Cameron & Chase (1999), is paraphyletic. The North American species of Cleistes are more related to the North American-Asiatic genera Isotria and Pogonia than to the remaining species of Cleistes. The subtribe Pogoniinae is also paraphyletic. The saprophytic genus Pogoniopsis is more related with Galeola and Cyrtosia (Galeolinae) than to the remaining genera currently recognized within subtribe Pogoniinae. The Amazonian genus Duckeella, sister of all remainder of Pogoniinae, lacks the synapomorphic characters that define this subtribe, and should be transferred to the subtribe Duckeellinae. Species of the genus Cleistes present micromorphology of the epicuticular waxes of the leaves varying from a singular film to forming granules or platelets. The epicuticular waxes in Cleistes are constituted mainly by alcohols, acids and esters. The chemical compounds of epicuticular waxes of Cleistes were very variable among species, and may be used for specific delimitation within the genus. Species of Cleistes, as for remaining Pogoniinae, are pollinated mainly by bees, although C. libonii is co-pollinated by hermit hummingbirds. The South American species of Cleistes presents flowering peaks, in which all mature buds of each plant flowering simultaneously on the same day. The studied species produced short-lived flowers (generally one day), which offer nectar as reward produced by two nectariferous glands on the basis of the lip. For the North American-Asiatic genera these nectariferous glands are absent and the floral visitors are attracted by deceit. This study supports the evolution of deceptive flowers to nectar flowers
Doutorado
Biologia Vegetal
Doutor em Biologia Vegetal

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Cyrtopodium eugenii Rchb. f. (Orchidaceae) is a specie widely distributed in Brazilian savannah, being the Planalto Central its main center of diversification. C. eugenii is a terrestrial specie, usually found in the Cerrado, growing in sand soil, dry environment and to the half shade. Due the beauty and exotic character of its flowers, C. eugenii present high ornamental and commercial potential. However, no studies were found of its preservation even in vitro protocols for shoots obtainment to be used in flower production. Thus, the present study has as objective to characterize the fenology, morphology and reproductive biology in C. eugenii and to establish protocols for symbiotic and asymbiotic germination in vitro. The plants studied grows at the Biological Reserve Prof. Jose Ângelo Rizzo, a forest remainder of 500 ha of bioma Cerrado, whose predominant vegetation is of the type Cerrado Rupestre, located in the Serra Dourada, city of Mossâmedes-GO. From the months of July of 2007 through August of 2008 monthly visits had been carried out for accompaniment and collects of data of 51 plants, distributed in three populations. For the establishment of the germination protocols in vitro of C. eugenii established the symbiotic culture, pairs the isolated fungic contends the mycorrhizae Epulorhiza sp., obtained from roots of C. eugenii, with the seeds of C. eugenii in medium FA, and the asimbytic culture, where the seeds had been cultivated in culture mediuns that are regularly used for seed orchids germination, being the complete MS medium, the MS medium with reduction to the half of the concentration of macronutrients (½ MS) and the Knudson medium (KC). The analysis of the behavior of C. eugenii allowed to verify that this species present annual budding and at the dry time. At the rainy time, when the temperature raised, plants of C. eugenii start to invest its energy in the production of vegetative parts, such as sprouts of pseudobulbs and leves. The flowers of C. eugenii are disposed of cyclical form in the floral connecting rods, which arrive to reach up to 130 cm of height. This species is self-compatible, even so in natural conditions, the fruit set is low. Not evidenced was presence of efficient pollinators. High frequency of ants during budding of C. eugenii was verified. However, the observations indicated that these insects only act as visitors and they are attracted by the secretion of substance at the time of the budding throughout the floral connecting rod and that have high concentration of soluble solid. The establishment of the symbiotic germination in vitro did not disclose resulted satisfactory because no protocorms formation were obtained. However, satisfactory results had been founded in the asymbiotic germination in vitro, being the ½ MS medium superior to the KC and the complete MS medium for the time, germination of seeds and establishment of new plants of C. eugenii.
A espécie Cyrtopodium eugenii Rchb. f. (Orchidaceae) é amplamente distribuída pelo Brasil, sendo o Planalto Central o seu principal centro de diversidade. C. eugenii é uma espécie terrestre, comumente encontrada no Cerrado, crescendo em solos arenosos, ambientes secos e à meia sombra. Devido ao caráter exótico de sua inflorescência e à beleza de suas flores, C. eugenii apresenta elevado potencial ornamental e comercial. Entretanto, não são encontrados estudos para sua preservação ou métodos para obtenção de mudas que possam ser utilizadas na floricultura ou no paisagismo. Assim, o presente estudo tem como objetivos caracterizar a fenologia, a morfologia e os apectos reprodutivos desta espécie de orquídea e estabelecer protocolos para germinação simbiótica e assimbiótica in vitro. Parte do trabalho foi desenvolvida na Reserva Biológica Prof. José Ângelo Rizzo, um remanescente florestal de 500 ha do bioma Cerrado, cuja vegetação predominante é do tipo Cerrado Rupestre, localizada na Serra Dourada, município de Mossâmedes GO. No período de julho de 2007 a agosto de 2008 foram realizadas visitas mensais para acompanhamento e coleta de dados fenológicos e de biologia floral de 51 indivíduos, distribuídos em três sub-populações. Para o estabelecimento dos protocolos de germinação in vitro de C. eugenii estabeleceu-se o cultivo simbiótico, pareando o isolado fúngico contendo o micélio micorrízico de Epulorhiza sp., obtido a partir de raízes de C. eugenii, com as sementes de C. eugenii em meio FA, e o cultivo assimbiótico, em que as sementes foram cultivadas em meios de cultura comumente usados para germinação de orquídeas, sendo o meio MS completo, o meio MS com redução à metade da concentração de macronutrientes (½ MS) e o meio de Knudson (KC). A análise do comportamento de C. eugenii permitiu verificar que esta espécie apresenta floração anual e na época seca. Na época chuvosa, quando a temperatura é mais elevada, plantas de C. eugenii passam a investir sua energia na produção de partes vegetativas, tais como brotos de pseudobulbos e folhas. As flores de C. eugenii são dispostas de forma cíclica nas hastes florais, as quais chegam a atingir até 130 cm de altura. Esta espécie é autocompatível, embora em condições naturais, a taxa de frutificação seja baixa. Não foi observada presença de polinizadores eficientes. Foi verificada elevada freqüência de formigas durante a floração. Porém, as observações indicaram que estes insetos atuam apenas como pilhadores e que são atraídos pela secreção de uma substância liberada constantemente na época da floração ao longo da haste floral e cujo teor de sólidos solúveis é elevado. O estabelecimento da germinação simbiótica in vitro não revelou resultados satisfatórios uma vez que a formação de protocormos não foi obtida. Todavia, resultados satisfatórios foram encontrados na germinação assimbiótica in vitro, sendo o meio ½ MS superior ao KC e ao MS completo para o tempo, taxa de germinação de sementes e estabelecimento de novas plântulas de C. eugenii.

Cette thèse aborde l’écologie et l’évolution des relations qu’entretiennent les orchidées du genre Ophrys avec leurs pollinisateurs. L’approche comparative et la combinaison (i)

d’analyses chimiques de phéromones sexuelles et de parfums floraux, (ii) d’analyses génétiques avec des outils moléculaires, et (ii) de tests de comportement réalisés sur les insectes in situ nous ont permis d’éclairer certains aspects méconnus de ces interactions inter-spécifiques. La pollinisation des orchidées du genre Ophrys est assurée par des mâles d'abeilles ou de guêpes solitaires qui opèrent une tentative d’accouplement (pseudocopulation) sur le labelle des fleurs. L'attraction des pollinisateurs est généralement hautement spécifique, régie par un mimétisme des signaux (chimiques, visuels, tactiles) des femelles des espèces d'insectes concernés. Malgré cette spécificité, des hybrides se forment occasionnellement en conditions naturelles, témoignant de la perméabilité partielle des barrières d'isolement reproductif entre espèces. Au cours de

ce programme de recherche, nous avons entrepris l’étude des interactions Ophryspollinisateurs en mettant l’accent sur trois aspects spécifiques, à savoir (i) la sélection des caractères floraux par les pollinisateurs, (ii) l'isolement reproductif entre espèces d'Ophrys sympatriques, et enfin (iii) l'évolution des caractères floraux au sein d'un complexe d'espèces-soeurs d'Ophrys associées à différents pollinisateurs. Les principaux

résultats de ce travail sont repris ci-dessous, ponctués de références aux articles qui rassemblent l’intégralité des études réalisées.
Doctorat en Sciences
info:eu-repo/semantics/nonPublished

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
A realização do trabalho objetivou desenvolver uma técnica comercial de aplicação do ácido giberélico via pulverização foliar para o controle da floração de orquídeas Phalaenopsis, Cattleya e Brassocattleya, além da redução do tempo para a primeira florada em Phalaenopsis, fatores limitantes no cultivo. Os experimentos foram realizados no Setor de Biotecnologia e Orquidicultura da Fundação Shunji Nishimura de Tecnologia, Pompéia-SP. Foram conduzidos três experimentos. Como híbridos foram utilizados Cattleya Ireni Holguim, Brassocattleya Marcela Koss, Phalaenopsis FSNT Snow F1 e Phalaenopsis FSNT Dai-Itigô. Para C. Ireni Holguim e Bc. Marcela Koss testaram-se 4 concentrações de GA3 (125, 250, 500 e 1.000 mg L-1) em 4 aplicações com intervalos de 7 dias via pulverização foliar, nos meses de Outubro/Novembro para Bc. Marcela Koss e Janeiro/Fevereiro para C. Ireni Holguim, em plantas adultas, além de 2 condições hídricas (sem e com estresse hídrico). Não foi possível induzir a floração em Cattleya Ireni Holguim com o uso de GA3. Para Bc. Marcela Koss, a associação da aplicação de 250 mg L-1 de GA3 e a colocação das plantas em condições de estresse hídrico induziu cerca de 83% das plantas a florescerem fora da época normal de florescimento. Na mesma concentração de GA3, porém em condições normais de irrigação, apenas 17% das plantas foram induzidas a florescer. O número e o tamanho das flores aumentaram com o aumento das concentrações de GA3 utilizadas no experimento. Também se testou a utilização do ácido giberélico (GA3) na indução floral fora de época e qualidade do florescimento de orquídeas adultas de Phalaenopsis FSNT Snow F1, híbrido de coloração branca. Foram realizadas duas e 4 aplicações de GA3, a intervalos de 7 dias nos meses de Novembro/Dezembro. O melhor resultado...
The objective of this works was to develop a commercial technique to control blooming in orchids, via the use of foliar sprays with gibberellic acid in Phalaenopsis, Cattleya, and Brassocattleya orchids, in addition to reducing the time required for the first blooming in Phalaenopsis, which are factors that restrict growth. It was conducted three works. The influence of gibberellic acid and water stress on the induction and quality of flowering was tested in two hybrid genera of orchids, Cattleya and Brassocattleya. The experiment was conducted at the Biotechnology and Orchidculture Sector of the Shunji Nishimura Technology Foundation, in Pompéia, SP. As hybrids was use Cattleya Ireni Holguim, Brassocattleya Marcela Koss, Phalaenopsis FSNT Snow F1 and Phalaenopsis FSNT Dai-Itigô. In C. Ireni Holguim and Bc. Marcela Koss, four GA3 concentrations (125, 250, 500, and 1,000 mg L-1) were tested in four applications at 7 day- intervals by foliar sprays on adult plants, in addition to two humidity conditions (with or without water stress). Applications were made in October/November in Bc. Marcela Koss and January/February in C. Ireni Holguim. It was not possible to induce flowering in Cattleya Ireni Holguim with gibberellic acid. In Brassocattleya Marcela Koss, the association between 250 mg L-1 GA3 and plants grown under water stress conditions induced blooming in 83% of plants treated under adverse conditions. At the same GA3 concentration, but without water stress, only 17% of the treated plants bloomed. The number and size of flowers increased as GA3 concentration increased. Another objective of this work was to test the use of GA3 to induce off-season flowering and improve blooming quality in adult Phalaenopsis FSNT Snow F1. Four GA3 concentrations (125, 250, 500, and 1,000 mg L-1) in 2 and 4 applications (at 7-day intervals) were tested. Spray applications were ...(Complete abstract click electronic access below)

Orchis italica è un’orchidea selvatica mediterranea appartenente alla sottofamiglia Orchidoideae delle Orchidaceae, una delle più vaste famiglie di piante a fiore. Lo scopo di questo lavoro è lo studio dei geni coinvolti nella determinazione della simmetria bilaterale del fiore di O. italica. Studi sulla determinazione della simmetria fiorale effettuati sulla specie modello Antirrhinum majus hanno evidenziato che cinque geni, due appartenenti alla famiglia TCP (CYC e DICH) e tre appartenenti alla famiglia MYB di fattori di trascrizione (DIV, RAD e DRIF), svolgono un ruolo cruciale nella formazione del fiore zigomorfo. In A. majus queste proteine interagiscono tra di loro attraverso un meccanismo antagonistico che permette la formazione nel fiore di una regione dorsale e una ventrale. In O. italica, l’analisi del trascrittoma dell’infiorescenza matura ha evidenziato la presenza di 8 trascritti DIV-like, 4 trascritti RAD-like e due trascritti DRIF1/2. L’organizzazione genomica dei geni DIV-like e RAD-like presenta un singolo introne, fatta eccezione per un unico gene RAD-like che risulta essere privo di introni. L’analisi evolutiva ha evidenziato che sulle regioni codificanti dei geni DIV-like e RAD-like agisce selezione purificante. I geni DIV, RAD e DRIF di O. italica hanno un’espressione conservata rispetto ad A. majus. L’analisi delle interazioni proteiche tra i fattori di trascrizione MYB di O. italica ha dimostrato che il modello alla base della determinazione della simmetria bilaterale sembra essere conservato anche in orchidea. I geni MADS-box di tipo II MIKCC, classificati in cinque classi funzionali ABCDE, hanno un ruolo cruciale della determinazione della struttura e dell’organizzazione fiorale. In particolare, in orchidea, secondo il modello “orchid code”, i geni MADS-box appartenenti alla classe B hanno un ruolo fondamentale nella formazione della struttura zigomorfa del fiore di orchidea. Nell’infiorescenza matura di O. italica sono espressi 29 trascritti MADS-box appartenenti al tipo I e al tipo II. I geni MADS-box di O. italica hanno un profilo di espressione in linea con il modello di sviluppo fiorale “fading borders”. Poiché entrambe le famiglie geniche, MADS-box e MYB, sono alla base della determinazione fiorale è stato effettuato uno studio sull’interazione proteica tra i fattori di trascrizione MYB (DIV, RAD e DRIF) e le proteine MADS-box di classe B di O. italica. L’analisi condotta ha evidenziato che le singole proteine MADS-box appartenenti alla classe B non sono in grado di interagire con i fattori di trascrizione MYB.

博士
國立成功大學
生命科學系
102
The typical orchid floral morphology architecturally consists of three sepals, two petals, together with the most sophisticated lip, and colum. Previous studies reveal that lip plays a critical role in orchid pollination strategies. Orchid flower, remarkable for its zygomorphic syndrome, is intently related to the Orchidaceae evolutionary history. The evolution of lip is one of the major factors for orchid flower exhibiting zygomorphy to derived from the actinomorphy lily-like flower. This thesis investigates the B- and E-class MADS genes in determining orchid floral organ identities, and the Homeotic Orchid Tepal (HOT) model is proposed for explicating floral morphogenesis in Orchidaceae. Tweenty seven AP3-like and 14 PI-like genes from 12 species of orchids were widely identified. Homologous genes of PI clade and four duplicated AP3A1, AP3A2, AP3B1, and AP3B2 subclades were conserved in the orchid family. Among the four AP3 subclades, the lip specificity of orchid AP3A2 orthologs was demonstrated by the differential transcript between petal and lip of normal flowers and by the ectopic expression in lip-like petal of orchids with peloric flowers. Although an AP3A2-like gene was identified in lily-like Neuwiedia flower without obviously modified lip, the primitive AP3A2 maybe necessary but not sufficient for regulating lip development. Based on these results, the HOT model was proposed, in which dualistic characters of duplicated B-class MADS-box genes are involved in orchid perianth development and growth, especially the formation of the modified petal, lip. Furthermore, I functionally characterized the PeSEP genes that are uniformly expressed in all floral organs in respects of protein-protein interaction and gene expression by using of yeast two-hybrid and VIGS. PeSEPs themselves and possibly via regulating their downstream B-class genes involved in stimulating cell shape, cellular ultra-structures, floral pigmentation and cutin biosynthesis, but inhibiting features of leaf-like structures to determine the development of orchid sepals, petals and lip. Together, these studies have clarified the relationship of orchid B- and E-class MADS-box genes involved in the regulation of orchid floral organ identities and uncovered the critical roles in the obscure mystery of the orchid perianth morphogenesis.

碩士
國立中興大學
生物科技學研究所
95
Flowering in higher plants involves the transition of vegetative development into floral initiation and formation and results in the production of flowers. The goal for this study is to clone and characterize orchid (Oncidium Gower Ramsey) genes regulating flowering time for further practical application of these genes in floral quality improvement. LEAFY (LFY) and MADS Box gene APETALA1 (AP1) are specific meristem identity regulator in controlling floral transition in plant. We report here the isolation of OnLFY, the orthologue of LFY from O. Gower Ramsey that encods a 467 amino acids protein and share 58% identity to rice OsRFL. RT-PCR analysis indicated that OnLFY was expressed in young flower primordia. Ectopic expression of OnLFY promoted flowering time in transgenic Arabidopsis. To investigate the flower formation of orchid, two MADS box genes, OMADS10 and OMADS11, were isolated from O. Gower Ramsey and functionally characterized in this research. OMADS10 showed a high similarity to the A function MADS Box gene AP1. RT-PCR analysis indicated that OMADS10 was expressed in all the organs and developmental stages tested. OMADS11, with high similarity to the E function MADS Box genes such as SEP1/2, was only expressed in flower and in all different floral parts. 35S::OMADS10 transgenic Arabidopsis plants flowered extremely early and produced terminal flowers. Transgenic Arabidopsis plants ectopically expressing OMADS11 also showed novel phenotypes resembling 35S::OMADS10 plants by significantly reducing plant size, producing curly leaves, flowering early, and losing inflorescence indeterminacy. Our result provided evidence to show that OnLFY, OMADS10 and OMADS11 play multiple roles in regulating both floral transition and formation in orchid. The RNA interference technology was applied to generate transgenic mutants to further investigate the function for these genes.

There are few other structures in nature from which evolution has generated such wide diversity as the flower or inflorescence, and this diversity is commonly attributed to the influence of their animal visitors. By outsourcing their mate choice to pollinators, plants have left themselves - and especially their flowers - subject to the selective forces imposed by the behaviour, cognition and perception of the pollinators that serve them. The orchids provide some of the most remarkable and extreme examples of adaptations to specific animal pollinators. Perhaps one of the most peculiar of these strategies is sexual deception, whereby male insects are lured to the flower by mimicry of the female sex pheromone. This seemingly unlikely strategy has evolved multiple times independently on different continents in different parts of the orchid phylogeny which raises the question of what adaptive advantages might underlie such a strategy. This multidisciplinary thesis studies gene flow and pollinator behaviour in two sympatric sexually deceptive orchids in the genus Chiloglottis. The two species attract their specific wasp pollinators through emission of distinct species - specific semiochemicals. Since floral volatiles play a pre-eminent role in pollinator attraction, Chiloglottis provides an excellent case study for examining the interaction between floral volatile chemistry, pollinator behaviour and the evolutionary dynamics of populations. The thesis begins with a review of floral volatiles and their role in pollinator attraction and plant speciation. The literature is used to develop a research framework of six testable hypotheses under which we might productively explore the influence of floral volatiles on plant evolution. These hypotheses are then explored in the study system over the following chapters. A study of pollinator specificity, neutral genetic differentiation and floral chemistry demonstrates that the chemical mimicry crucial to sexual deception is responsible for reproductive isolation and potentially even speciation. Mating system and paternity analysis provide the first genetic evidence for multiple paternity in orchid broods. Extensive outcrossing is found to predominate and paternity assignment shows evidence for long distance pollen flow supporting the hypothesis that sexual deception promotes outcrossing and so minimizes the potentially deleterious effects of selfing. Lastly, an innovative new method is developed for tracking wasps in the field. Application of this technique to a population of orchid-pollinating wasps reveals detailed information about their movement and mating behaviour. The findings support the conclusion that sexual deception is a superb adaptive solution to the problem flowers face of simultaneously attracting pollinators and persuading them to leave quickly.

碩士
國立成功大學
生命科學系
103
ABSTRACT Phalaenopsis bellina is a scented Phalaenopsis species. The main scent components of P. bellina are monoterpenes including linalool and geraniol with the maximal emission on day 5 post anthesis (D+5). The key enzyme gene for monoterpene biosynthesis in P. bellina is geranyl diphosphate synthase small subunit (PbGDPS_SSU), whose expression is concomitant with the maximal emission of floral scent. Previously, the floral scent production was detected mainly from 10 am to 4 pm for P. bellina. It is possible that the floral scent emission was either light or temperature regulated. We have analyzed whether the scent emission is circadian rhythm or light regulated by either under long-day (16 h/8 h light/dark) or continuous darkness conditions for 4 days since D+4. We found that the emission of orchid floral scent is light-regulated rather than circadian rhythm regulated. In addition, transcriptomic analysis of P. bellina flowers at consecutive stages (from the blooming day to D+7) showed that several photoreceptor genes displayed concurrent expression patterns as that of PbGDPS_SSU, including phytochrome (PHY), cryptochrome (CRY), phototropin (PHOT), and UVBR. Transcription of these unigenes was then verified by using quantitative real-time RT-PCR. Two blue light photoreceptors, PbCRY3 and PbPHOT1, showed similar expression patterns with PbGDPS_SSU. To investigate the role of blue light on floral scent emission in Phalaenopsis, the scent metabolic profiles of two native Phalaenopsis species and two commercial cultivars were analyzed by treating plants with various light factors. The emission levels of linalool and geraniol were higher in these plants under long day condition (white light 100 μmol m-2s-1, 16 h/8 h L/D) than those under far-red light or darkness. In addition, high intensity of blue light (270 μmol m-2s-1) showed a negative effect on the emission of linalool and geraniol in two native species, with more effect on linalool than geraniol. Taken together, these results indicate that light has played a positive effect on orchid floral scent emission, and the effect of light regulation on linalool and geraniol emission might be different.

碩士
國立成功大學
熱帶植物科學研究所
104
Phalaenopsis orchids are important crops with high economic value worldwide. However, breeding of scented Phalaenopsis orchids are with difficulties and thus the breeders usually have little successful targets on breeding orchids with floral scent. For time saving, molecular markers detecting the scent production is needed. Phalaenopsis bellina has sweet floral fragrance consisted of monoterpenes, and it usually is a seed or pod parent for breeding scent Phalaenopsis orchids. Previously, P. bellina geranyl diphosphate synthase (PbGDPS) is identified as the key enzyme for monoterpenes biosynthesis. In addition, the GDPS promoter from 10 native Phalaenopsis species were isolated and analyzed. They were very similar except the presence or absence of a tandem repeat sequences. In previous study, in scented Phalaenopsis species, the tandem repeat sequences were complete, and the GDPS was expressed. However, in scentless species, the incomplete tandem repeat sequences were detected and without GDPS expression. In this study, for developing the molecular marker from the tandem repeat sequences of GDPS promoter to detect the scent of monoterpene production, GDPS promoters of 14 native species Phalaenopsis spp. were amplified and analyzed. The PCR-amplified tandem repeat fragments in the promoter region showed 2 fragments of 400 bp and 300 bp. Sequence analysis showed that they were very similar except the presence or absence of two complete sets of tandem repeats. The 400-bp fragment contains the complete tandem repeats of repeat 1 and repeat 2, and each repeat can be subdivided as ABCD and A’B’C’D’ regions. The 300-bp fragment has a deletion of the repeat 1 and contains only the A’B’C’D’ regions. However, in some native species, the deletion of tandem repeat sequences did not affect the expression of GDPS. Furthermore, a population with 25 F1 progenies and their putative parents were analyzed for the development of molecular markers for assessing floral scent. Intriguingly, the single nucleotide polymorphisms (SNPs) occurred in the D region of tandem repeat in GDPS promoter might cause low production of monoterpene. However, no mutations were detected in the A’ region of the 400-bp fragment and the D’ region of the 300-bp fragment for all 14 native species regardless with or without scent. Most SNPs and large deletion existed in the repeat 1 rather than repeat 2. These results suggest that the repeat 2 is more conserved than the repeat 1 and may play an important role in orchid evolution for scent traits. In addition, the tandem repeat sequences of GDPS promoter may have potential to develop as molecular markers and apply for the early detection of the floral scent and facilitates scent orchid breeding in the future. However, the commercial cultivars which contain the parenthood of P. schilleriana, P. aphrodite subsp. formosana and P. amboinensis var. common were not suitable because their results were not so consistent with those in this study.

Orchids provide a model system for addressing evolutionary and ecological questions both because of their species diversity, and because the packaging of their pollen into pollinia facilitates the estimation of male and female pollination success. This thesis focuses on the ecology and evolution of pollination systems in the African orchid genus Eulophia, with an emphasis on deceptive pollination, mechanisms promoting cross-pollination, and pollinatordriven speciation. Pollination in the deceptive species E. zeyheriana is shown to depend on flower colour and proximity to the rewarding model species, Wahlenbergia cuspidata (Campanulacae). This study demonstrates the functional importance of colour matching between model and mimic in a floral Batesian mimicry system, as well as the importance of facilitation by the rewarding model [chapter 2]. The pollinaria of the vast majority of Eulophia and Acrolophia species undergo reconfiguration following removal by pollinators, similar to the phenomena first described by Darwin in some European orchids and which he hypothesised to be adaptations to limit pollinator mediated self-pollination. In chapter 3, a less common mechanism – anther cap retention – is described for E. foliosa. Observations of reconfiguration times were compared to the respective visit times by pollinators in a number of orchids (including Eulophia and Acrolophia) and asclepiads. In 18 of 19 species, pollinarium reconfiguration times exceed the average visit times, providing empirical support for Darwin’s cross-pollination hypothesis [chapter 4]. All of the 25 species of Eulophia examined are deceptive, but two of the three species in the small, closely related Cape genus Acrolophia examined in chapter 5 are rewarding. This translates into very high levels of pollen transfer efficiency in the rewarding A. cochlearis relative to the deceptive A. capensis and species of Eulophia. In addition, A. cochlearis exhibits high rates of pollinator-mediated self-pollination, as quantified using a novel method based on levels of inbreeding depression during embryo development. In chapter 6 the evolutionary divergence of long- and short-spurred forms of E. parviflora in response to different pollinators is investigated. This shows that divergence has occurred in floral morphology, scent chemistry and flowering phenology and that this can be attributed to adaptations to the respective bee and beetle pollinators of each form. This thesis also includes case histories of bee pollination in an additional five Eulophia species, and beetle-pollination in two other species of Eulophia with dense inflorescences and slow pollinarium reconfiguration [chapter 7]. In addition, four taxa were found to undergo auto-pollination [chapter 8]. The main conclusions of this thesis are that pollination of food-deceptive species can be enhanced by spatial proximity to, and floral colour matching with, sympatric rewarding species; that selection strongly favours traits that promote cross-pollination; that pollinatorshifts can drive speciation; and that floral adaptations for bee-, beetle-, and auto-pollination are found in South African representatives of Eulophia.
Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2009.

碩士
國立屏東科技大學
農園生產系所
96
The genes controlling floral symmetry in Antirrhinum encode proteins belonging to the TCP and MYB gene families. The purpose of this study was to clone the TCP and RAD genes and to compare their expression in relation to morphological changes in Doritaenopsis. Petals of the peloric mutants presented labellum-like protuberance at 0.2 cm flower bud. Occasionally peloric mutants lack pollinia. There were at least two copies of TCP and RAD in the Dtps. Sogo Vivien ‘F858’ genome, and at least one copy and four copies of TCP and RAD in Phal. Little Mary genome, respectively. RT-PCR analysis showed that TCP was preferentially expressed in flower, and weaker in root tips and leaves. Peloric mutants showed similar expression pattern but with lower level than the wild-type. Expression level of RAD was higher in wild-type than the mutants. In situ hybridization analysis showed that TCP and RAD genes were preferentially expressed in florescence meristem and floral primordia.

Tese de doutoramento, Biologia (Biologia Celular), Universidade de Lisboa, Faculdade de Ciências, 2016
The study of the micromorphology of flowers is crucial to understand the complex process of pollination and the intimate interaction between flowers and pollinators. This plant‐pollinator interaction is a key factor to the diversification and evolution of angiosperms and is particularly tight in species pollinated by sexual deception, almost all of which belonging to the orchid family. The highly specific pollination system of the sexually deceptive species is based on a precise mimicry of the visual, tactile and chemical signals exhibited by the females of the pollinator species (usually a single or a few related insect species), thereby attracting males, which, in most cases, perform copulatory attempts with the flower leading to pollination. In the Euro‐Mediterranean sexually deceptive orchid genus Ophrys, most research has been focused on the chemical mimicry between certain components of the odour bouquet emitted by the flowers and the female sex pheromone of their specific insect pollinators. In most cases, these compounds were shown to be mainly long‐chained hydrocarbons, which are found in the cuticular waxes spread over the surface of the strongly modified median petal typical of orchid flowers – the labellum. However, numerous compounds of higher volatility were shown to act as long‐range attractants for male pollinators, although their site of synthesis and emission (presumably an osmophore) remains unknown. Likewise, little is known about the micromorphological features of the labellum and their importance in providing visual and tactile signals for pollinator attraction. In the present thesis, we investigated the location, structure and secretion of the osmophore and the labellum micromorphology and anatomy of flowers, at three developmental stages, of six closely related Ophrys taxa from natural populations occurring in Portugal, using scanning electron microscopy, light microscopy and histochemistry. We demonstrated the occurrence of an osmophore, which synthesizes a terpene‐rich lipophilic secretion, in the apical region of the labellum in the investigated Ophrys taxa, located mainly at the labellum margin and/or in an apical appendix exhibited by some species. A great diversity of epidermal cell types was found in the adaxial surface of the labellum, which form well‐defined areas with distinct visual and tactile properties. The detailed comparative analysis of these different areas allowed us to establish potential homologies between the labellum areas of the studied taxa. The Ophrys osmophore probably plays an important role in pollination, by synthesizing highly volatile long‐range pollinator attractants, which are possibly complementary to the cuticular waxes spread over the labellum surface for the success of pollination by sexual deception. Findings of the micromorphological and anatomical study were used to build a morphoanatomical data matrix, using objective criteria, as a basis for a morphological phylogenetic analysis of the unresolved clade of Ophrys formed by the six studied taxa, using maximumparsimony and Bayesian inference. Our phylogenetic hypothesis rejects an earlier morphological hypothesis and favours the existing molecular phylogenetic trees based on nuclear ITS data rather than plastid data. Furthermore, the present analysis brought some insights into the floral trait evolutionary trends in Ophrys orchids.
Fundo Social Europeu (FSE), III Quadro Comunitário de Apoio (2000-2006), Programa Operacional Ciência e Inovação 2010 (POCI 2010)

博士
國立成功大學
生命科學系
103
Phalaenopsis orchids have become very popular for their long-lasting flowers with elegant floral morphology and various flower colors. Development of new cultivars is economically important for floricultural industry worldwide. This thesis contains two parts: (1) analysis of the genome structure and composition, and (2) study of the regulatory mechanism for the promoters of B-class floral organ identity genes and the transcription factors regulating flower color in Phalaenopsis. For the first part, pair-end sequences from 2,920 bacterial artificial chromosome (BAC) clones of P. equestris were analyzed for the compositions of protein-coding regions, repeat sequences, and microsatellites in the P. equestris genome. The LTR-retrotransposons were identified from the BAC end sequences (BESs) and partial genome sequences, and examined for their retrotransposition/recombination events and effects on Phalaenopsis genome sizes. Their copy numbers were assessed in the genome sequences of four Phalaenopsis species with either small or large chromosomes. For the second part of studying the regulation of orchid morphogenesis, the promoter sequences of five B-class MADS-box genes (PeMADS2~6) were identified and analyzed. These included four APETALA3 (AP3)-like PeMADS2~5 and one PISTILLATA (PI)-like PeMADS6, displaying distinct expression profiles in various floral organs and specifying the spectacular flower morphology in orchids. Further studies on DNA methylation and histone modification status of PeMADS2~6 were performed. The regulation via the upstream sequences as well as increased histone acetylation levels may involve in the distinct expression profiles of the AP3-like genes for Phalaenopsis floral morphogenesis. To investigate the floral pigmentation patterning, genome-wide identification of regulatory genes involved in the flower color and anthocyanin biosynthesis pathway in Phalaenopsis, such as MYBs was performed. Three R2R3-MYB transcription factors, PeMYB2, PeMYB11, and PeMYB12, were characterized for their roles in regulating three distinct floral pigmentation patterns, full-red, red-spot, and venation patterns, respectively, in one single flower of Phalaenopsis. In addition, various ratios of these three PeMYBs were concomitant with distinct floral pigmentation patterns in six commercial cultivars. These results unravel the complicated regulation of anthocyanin pigmentation patterning in Phalaenopsis which leads to the highly abundant color patterns in orchid flowers. All these results together improve our knowledge on the genome composition and the regulation of floral morphogenesis and pigmentation patterning in Phalaenopsis orchids through genomics approach.

博士
國立中興大學
生物科技學研究所
104
In this study, we analyzed the relationships between Forever young flower (FYF) and Ethylene response DNA binding factors (EDFs) in regulating flower senescence/abscission. Strong GUS staining was detected in the mature flower and staining decreased in young flowers of the EDF1/2/3/4::GUS transgenic Arabidopsis. This result was opposite to FYF::GUS plants. 35S:EDF1/2/3/4 and 35S::EDF1/2/3/4+SRDX caused similar promotion of flower senescence/abscission and the activation of the senescence-associated genes SAG12, AtMCs and VPEs, indicating that EDF1/2/3/4 function as repressors in promoting senescence/abscission. EDF1/2/3/4 function downstream of FYF in the ethylene signaling pathway, and this finding was further supported by the observations that 35S::EDF1/2/3/4+SRDX rescue the delayed senescence/abscission phenotypes in the etr1 and ein2 mutants and in 35S::FYF plants. The 35S::FYF significantly reduced GUS expression in EDF1/2/3/4::GUS plants. These results indicate that FYF delayed flower senescence/abscission by repressing transcriptional repressor EDF1/2/3/4. To analyze the FYF and SVP orthologs from orchid, Oncidium short vegetative phase1/2 (OnSVP1/2), Cattleya forever young flower1/2(CaFYF1/2) and Cattleya short vegetative phase (CaSVP) were identified from Oncidium Gower Ramsey and Cattleya intermedia. 35::OnSVP1/2+SRDX delayed flower senescence/abscission by down-regulating EDF1/2/3/4, BOP2, IDA, HAESA in transgenic Arabidopsis. Furthermore, 35::OnSVP1/2+SRDX transgenic Arabidopsis were insensitive to ethylene. 35::CaSVP+SRDX, 35::CaSVP, 35::CaFYF1/2+SRDX and 35::CaFYF1/2 also delayed flower senescence/abscission by down-regulating ethylene and abscission signaling in transgenic Arabidopsis. Our results revealed that FYF and SVP orthologs from orchids function as a repressor to delay flower senescence/abscission in transgenic Arabidopsis.