Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / A Cattleya violacea Rolfe (1889) é considerada a orquídea símbolo de Roraima, sendo muito apreciada por colecionadores, orquidófilos e produtores, que almejam cultivar essa espécie em suas coleções. Objetivou-se com este trabalho desenvolver um protocolo de cultivo in vitro para a C. violacea utilizando meios de cultura alternativos ao ágar e aos sais e vitaminas que compõem o meio tradicional Knudson C, no intuito de reduzir os custos dessa forma de reprodução de orquídeas. As plântulas utilizadas nesta pesquisa foram oriundas da germinação in vitro de C. violacea estriata com 1,0 cm de altura e com 02 folhas. Os meios de cultura testados foram compostos por ágar, vermiculita e carvão vegetal adicionados de 60,00 g L-1 de polpa das frutas regionais cupuaçu (Theobroma grandiflorum Schum [Willd. Ex. Spreng]), buriti (Mauritia flexuosa L.), cajá (Spondiaslutea L.), açaí (Euterpe oleracea Mart.), graviola (Anona muricata L.) e murici (Birsonima crassifolia L.) acrescidos de 40,0 ml L-1 de água de coco, de 2,0 g L-1 de carvão ativado e 20,0 g L-1 de sacarose. O pH do meio foi ajustado para 5,7 0,1. O delineamento experimental utilizado foi o inteiramente casualizado, com 18 tratamentos e 05 repetições contendo 05 plântulas por frasco. Os dados obtidos foram submetidos à análise de variância multivariada (AMOVA) e utilizou-se o teste de Tukey a 5% de significância. Os parâmetros biométricos avaliados nas plântulas após seis meses de subcultivo nos meios testados foram, altura da parte aérea, número de folhas, número de raízes, comprimento da maior raiz e número de brotos. Observou-se que os meios compostos por ágar e frutas proporcionaram os maiores crescimentos das plântulas de C. violacea quanto à altura da parte aérea, número de folhas e número de raízes, do que o meio tradicional Knudson C. Sendo que o meio composto por ágar e buriti promoveu o maior desenvolvimento das plântulas e o meio formado por buriti e vermiculita (BU2), em relação à variável número de brotos, influenciou positivamente na escolha do melhor meio de cultura estudado para o subcultivo de C. violacea. / Cattleya violacea Rolfe (1889) is considered the orchid symbol of Roraima, very appreciated by collectors, orchid growers and producers, that aims to cultivate this species in their collections. The objective of this work is to develop an in vitro cultivation protocol for C. violacea using alternative culture media to the agar and salts and vitamins that make up the traditional medium Knudson C in order to reduce costs for this form of reproduction of orchids . Seedlings used in this study were from in vitro germination of C. violacea estriata with 1.0 cm and 02 leaves. The tested media were composed of agar, vermiculite and charcoal added 60.00 g L-1 pulp regional fruit cupuaçu (Theobroma grandiflorum Schum [Willd. Ex. Spreng]), Buriti (Mauritia flexuosa L.) caja (Spondiaslutea L.), açaí (Euterpe oleracea Mart.), soursop (Annona muricata L.) and murici (Birsonima crassifolia L.) plus 40.0 L-1 ml of coconut water, 2.0 g L -1 activated and 20.0 g L-1 sucrose coal. The pH was adjusted to 5.7 0.1. The experimental design was completely randomized, with 18 treatments and 05 repetitions containing 05 seedlings per bottle. The data were subjected to multivariate analysis of variance (AMOVA) and used the Tukey test at 5% significance level. The biometric parameters evaluated in seedlings after six months of subculture media tested were, shoot height, number of leaves, number of roots, the greater root length and number of shoots. It was observed that the means consisting of agar, and fruit resulted in the highest growth of C. violacea as the seedling shoot height, number of leaves, number of roots, than the traditional means Knudson C. Since the medium composed of agar and Buriti promoted the further development of seedlings and the medium formed by Buriti and vermiculite (BU2), in relation to the shoot number, positively influenced the choice of the best culture medium studied for the subculture of C. violacea.

In this thesis, I focused mainly on orchids and also carried out some research on different pharmaceutically potential plants in Nepal. I compiled both data from field and secondary data sources and one of my first outputs was complete checklist of orchids in Nepal. I also studied distribution patterns and affinities of orchids with different floristic regions in Nepal. My next work on epiphytic orchids is related to diversity, distribution and host- species associations and their future in the context of climate change in Nepal. In addition to this, I also worked on factors affecting epiphytic orchids along an altitudinal gradient in central Nepal. Working on population dynamics of terrestrial orchid species, Crepidium acuminatum, lasted for 6 years. Together with orchids, I determined secondary compounds present in a highly important Nepal endemic medicinal plant, Swertia multicaulis. I also compiled the information on uses, phytochemistry, pharmacology and toxicity of highly important Himalayan endemic medicinal plant, Neopicrorhiza scrophulariiflora. The last research of my Ph.D. project ended up by gathering the information on uses of different medicinal plants, including orchids that were used to treat various gastrointestinal diseases in Nepal. The results of my doctoral thesis are presented...

Among terrestrial orchids, and particularly among the subtribe Orchidinae, flies are underrepresented as pollinators. The European Neotinea ustulata, which developed specialized pollination by tachinid flies, is known to produce high relative concentrations of the floral cuticular alkenes (Z)-11-tricosene and (Z)-11-pentacosene (referred to as (Z)-11-C23/C25enes), which seem to be uncommon among orchid flowers. If the evolution of tachinid pollination is related to that of (Z)-11-C23/C25enes, we can expect that closely related species have a different floral chemical pattern and significantly small or no production of (Z)-11-C23/C25enes, independently of their pollinator guild identity (e.g., bees, flies, moths). We chemically compared the floral cuticular composition among Neotinea species, performed electrophysiological analyses, reconstructed the phylogenetic Orchidinae tree, and identified the evolutionary history of pollinator guild and (Z)-11-C23/C25enes production within the Orchidinae. Neotinea ustulata has evolved a markedly different floral cuticular composition compared to other Neotinea and produces both compounds ((Z)-11-C23/C25enes) in high relative quantities (i.e., above 8% in combination), which are detectable by tachinid antennae. Moreover, most Orchidinae taxa have minimal or no production of these alkenes, independently of the identity of their pollinator guild. Our ancestral reconstruction suggested that (Z)-11-C23/C25enes production was an evolutionary exaptation in Neotinea, whereas tachinid pollination was a unique evolutionary innovation for N. ustulata. Floral cuticular composition and, in particular, the combined production of (Z)-11-C23/C25enes at relatively high concentrations is intimately linked to the evolution of tachinid pollination within the Orchidinae.

Orchids are ornamental plants cultivated by man long ago. The great diversity of colors and forms of the flowers of the species and natural and artificial hybrids adds to these plants high commercial value. The destruction of natural habitats, coupled with predation has led to the loss of genetic variability of the species, intensifying the already severe process of extinction.The aim of this study was to characterize native orchids of the SergipeState by ISSR molecular markers, as well as to study strategies for in vitro conservation under slow growth of three orchid species belonging to the subtribe Laeliinae. Two in vitro conservation experiments were realized, both in a completely randomized design. The first experiment was in a 3x3x2 factorial scheme, and we tested three combinations of carbon sources and osmotic regulators (20 g L-1of sucrose, 10 g L-1of sucrose + 5g L-1of mannitol, 10 g L-1of sucrose + 5g L-1of sorbitol), three orchid species (Epidendrum secundumJacq.,Encyclia dichroma (Lindl.) Schltr andCattleya tigrina A. Rich) and two temperatures (18 and 25°C).The second experiment was realized in a 4x3x2factorial scheme, and we tested four concentrations of salts of MS medium (100%, 75%, 50% and 25% of salts), three orchid species (Epidendrum secundumJacq.,Encyclia dichroma (Lindl.) Schltr andCattleya tigrina A. Rich) and two temperatures (18 and 25°C). The eight primers used in the study revealed a total of 87 fragments, all polymorphic, which proved effective in characterizing the collection of study. The diversity found within and between studied genera was high and promising for conservation studies.Cattleya tigrina presented 100% of survival at 180 days,and can be kept in medium with 25% of MS salts at 18°C. The temperature 18ºC also allowed the conservation of Epidendrum secundum for 365 days, with 100% of MS salts. Encyclia dichroma presented greater sensitivity to low temperature and can be kept at 25ºC with 25% of the salts of the MS medium for 365 days. / As orquídeas são plantas ornamentais cultivadas pelo homemhá muito tempo. A grande diversidade de cores e formas das flores das espécies e híbridos naturais e artificiais agrega a estas plantas alto valor comercial. A destruição dos habitats naturais, aliada à coleta predatória, tem levado à perda da variabilidade genética das espécies, intensificando o já acentuado processo de extinção. O presente trabalho teve como objetivo caracterizar por marcadores moleculares tipo ISSR orquídeas nativas do Estado de Sergipe, bem como estudar estratégias para conservação in vitro,sob crescimento lento, para três espécies pertencentes à subtribo Laeliinae. Foram realizados dois experimentos de conservaçãoin vitro, ambos em delineamento inteiramente casualizado.O primeiro experimento foi em esquema fatorial 3x3x2, onde foram testadas três combinações de fontes de carbono e reguladores osmóticos (20 g L-1 de sacarose; 10 g L-1 de sacarose + 5g L-1 de manitol; 10 g L-1 de sacarose + 5g L-1 de sorbitol), três espécies de orquídea (Epidendrum secundum Jacq.,Encyclia dichroma (Lindl.) Schltr eCattleya tigrina A. Rich) e duas temperaturas (18 e 25ºC). O segundo experimento foi em esquema fatorial 4x3x2, onde foram testadas quatro concentrações de sais do meio MS (100%, 75%, 50% e 25% dos sais), três espécies de orquídea (Epidendrum secundum Jacq.,Encyclia dichroma (Lindl.) Schltr, eCattleya tigrina A.Rich) e duas temperaturas (18 e 25ºC). Os oito primers utilizados no trabalho revelaram um total de 87 fragmentos, todos polimórficos, que se mostraram eficientes na caracterização da coleção de estudo. A diversidade encontrada entre e dentro dos gêneros estudados mostrou-se elevada e promissora para estudos de conservação. Cattleya tigrina apresentou 100% de sobrevivência aos 180 dias podendo ser conservada em meio com 25% dos sais MS à 18ºC. Esta temperatura também permitiu a conservação de Epidendrum secundum por 365 dias em meio com 100% dos sais MS. Encyclia dichroma apresentou maior sensibilidade à baixa temperatura e pode ser conservada a 25ºC em meio com 25% dos sais MS por 365 dias.

Thesis (MScAgric (Agronomy)--University of Stellenbosch, 2005. / The seven evergreen Disa species are indigenous to South Africa. These orchids grow on mountain ranges subject to winter rainfall and are found on stream banks, around waterfalls and in other damp areas. Although the Disa genus accommodates more than 130 species, by far the most commonly grown is Disa uniflora and hybrids stemming from this species. Disas have great potential as cut flowers and pot plants, but production techniques need to be further investigated since cultivation methods vary greatly between hobbyists. This study evaluated the effect of N-source, shading, root medium temperature, electrical conductivity (EC), irrigation method, foliar feeding at different plant growth stages and substrate on the growth of evergreen Disa hybrids in a controlled environment. Results showed that Disa plants can be classified as being ammonium tolerant. Disa unidiorosa performed best with 40% of the applied N in the NH4 form, while D.kewensis was more tolerant towards a higher level of NH4 and grew best at 60% NH4. Shading levels (56% and 69%) were compared and did not differ regarding the growth of plants. A cooled root medium was found to have a negative effect on root growth and a positive effect on leaf length. High EC levels produced heavier mother plants with a bigger root:shoot ratio and a bigger stem diameter. Biomass accumulation was the best in plants receiving ‘Drip’ irrigation, compared to ‘Ebb-and-Flood’ irrigation treatments. Plants in the vegetative reproducing stage were more susceptible to leaf abscission and new leaves formed at a low rate compared to small- and potential flowering plants. Where foliar feeding is concerned plants seemed to benefit more by the presence of NH4NO3 than urea. There were no significant differences in root development between substrates in the ‘hardening-off’ phase. ‘Hydroton’ (clay pebbles) was not suitable as substrate for the cultivation of Disa plants. The growth and flowering properties of plants were optimal with sphagnum moss and peat but were negatively affected when the pH of acid peat:sand mixtures were increased. More research is needed before Disas can be cultivated on a commercial scale, while the effect of the treatments on flowering properties has to be investigated.

All species of orchids are sensitive plants and records of their distribution are rare. Their rarity is related to their complex biology and their sensitivity to changes in the environment. It is necessary to pay attention to these threatened species, so that we could preserve them from extinction. For their effective protection we need to know the main causes of extinction of their localities. It is also useful to know the factors, which determine their distribution, so that we could find new localities, where they occur. In this thesis I analyzed some climatic, geographic and ecological factors in the Jeseníky mountains and their surroundings. First, I visited localities of orchids, which were registered in large databases of their presence in the past. The four most numerous species were analyzed using the program MaxEnt. Based on the revisions, existence of 2/3 of the revised localities was confirmed, 8% of the revised localities became extinct because of overgrowth or due to human intervention in the landscape. From the MaxEnt results it is clear, that for all species the most important factor at the 50 × 50 m scale, is the type of biotope and heterogeneity of the countryside. The most suitable biotopes are floodplain and wetland forests, mesophile meadows, natural scrubs, peat bogs and...

Made available in DSpace on 2014-07-29T16:24:21Z (GMT). No. of bitstreams: 1 Capa Camila Marillac.pdf: 113274 bytes, checksum: 456413e1a73b4f6c572c42092e6ba8a6 (MD5) Previous issue date: 2009-02-18 / 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.

Made available in DSpace on 2016-04-28T14:57:34Z (GMT). No. of bitstreams: 1 2008 - Everaldo Hans Studt Klein.pdf: 5165097 bytes, checksum: ccfbfbc6baec84bc829dad886555adf9 (MD5) Previous issue date: 2008-07-15 / It was conducted a survey of the major diseases that occur in orchids in the State of Rio de Janeiro, through collection of plants in various localities in the period April 2006 to June 2008. Fifty-three plants had their diseases and pathogens identified, of which 35.9% were infected by fungi, being 17% by Fusarium oxysporum, 13.2% by Colletotrichum gloeosporioides, 1,9% by Botrytis sp., 1,9% by Puccinia sp. and 1.9% by Phyllosticta capitalensis. 51% of the plants were infected by virus with simple and double infections of Cymbidium mosaic virus - CymMV and Odontoglossum ringspot virus - ORSV. 1.9% were infected by the bacterium Pectobacterium carotovorum subsp. carotovorum and 3.8% by nematodes of the genus Aphelenchoides. The nematodes Aphelenchoides fragariae and A. ritzemabosi were identified infecting hybrid orchids, which is the first report of parasitism of these nematodes in orchid and of A. ritzemabosi parasiting Asplenium nidus L. in Brazil. It also made the first record of the occurrence of Cymbidium mosaic virus - CymMV infecting Bamboo orchid Arundina bambusifolia Lindl. in the State of Rio de Janeiro. Based on the identification of pathogens of that survey, it was developed a diagnostic kit for the main diseases of orchids. Aiming to test antimycotic properties of three substances in culture medium for cultivation of orchids, using as test- plants Sophronitis cernua Lindl. and Epidendrum ellipticum Grah. Of the substances tested, only powdered cinnamon (Cinnamomum zeylanicum J. Presl), at the dose of 6 grams / liter positively influenced the germination of seeds of Epidendrum ellipticum Graham, and the addition of clove (Syzygium aromaticum) at doses of 3, 5 and 6 grams / liter caused the inhibition of in vitro germination of seeds of Epidendrum ellipticum Graham. and Sophronitis cernua (Lindl.) Hook. The addition of commercial garlic (Allium sativum L.) powder in doses of 6 and 10 grams / litre, also inhibited in vitro germination of seeds of Epidendrum ellipticum Graham. / Foi realizado levantamento das principais doen?as que ocorrem em orqu?deas no Estado do Rio de Janeiro, atrav?s de coleta de plantas em v?rias Localidades, no per?odo de abril de 2006 a junho de 2008. Cinq?enta e tr?s plantas tiveram suas doen?as e pat?genos identificados, dos quais 35,9% das plantas estavam infectadas por fungos, sendo 17% por Fusarium oxysporum, 13,2% por Colletotrichum gloeosporioides, 1,9 % por Botrytis sp., 1,9% por Puccinia sp. e 1,9% por Phyllosticta capitalensis. 51% das plantas estavam infectadas por v?rus com infec??es simples e duplas de Cymbidium mosaic virus - CymMV e Odontoglossum ringspot virus - ORSV. 1,9 % estavam infectadas pela bact?ria Pectobacterium carotovorum subsp. carotovorum e 3,8 % por nemat?ides do g?nero Aphelenchoides. Foram identificados os nemat?ides Aphelenchoides fragariae e A. ritzemabosi infectando orqu?deas h?bridas, sendo esse o primeiro relato de parasitismo desses nemat?ides em orqu?dea e de A. ritzemabosi em Asplenium nidus L., no Brasil. Foi feito tamb?m o primeiro registro da ocorr?ncia Cymbidium mosaic virus CymMV infectando plantas da esp?cie Arundina bambusifolia Lindl. no Estado do Rio de Janeiro. Com base na identifica??o dos pat?genos desse levantamento, desenvolveu-se um kit diagn?stico para os principais fitopat?genos de orqu?dea. Objetivou-se testar tr?s subst?ncias de propriedades fungist?ticas em meio de cultivo de propaga??o de orqu?deas, utilizando-se como plantas-teste Sophronitis cernua Lindl. e Epidendrum ellipticum Grah.. Das subst?ncias testadas, apenas canela em p? (Cinnamomum zeylanicum J.Presl), na dosagem de 6 gramas / litro influenciou positivamente a germina??o de sementes de Epidendrum ellipticum Graham, sendo que o acr?scimo de cravo-da-?ndia (Syzygium aromaticum) comercial picado nas doses de 3, 5 e 6 g/l causou a inibi??o da germina??o in vitro das sementes de Epidendrum ellipticum Graham. e Sophronitis cernua (Lindl.) Hook. O acr?scimo de alho (Allium sativum L.) em p? comercial nas doses de 6 e 10 g/l, tamb?m inibiu a germina??o in vitro das sementes de Epidendrum ellipticum Graham.

published_or_final_version / Ecology and Biodiversity / Master / Master of Philosophy

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.