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DIVERSITY RESOURCES, DISTRIBUTION AND PRESENT ECOLOGICAL STATUS OF HERMINIUM R. Br. A LESS KNOWN TERRESTRIAL ORCHID SPECIES OF DARJEELING HIMALAYA OF INDIA  [PDF]
Rajendra Yonzone1* D. Lama1, R. B. Bhujel2, Khyanjeet Gogoi3 and Samuel Rai4
Bioscience Discovery , 2012,
Abstract: The present paper deals botanical description with five Herminium viz., Herminium jaffreyanum, H. lanceum, H. mackinnonii, H. macrophyllum and H. quinquelobum terrestrial Orchid species diversity resources and distribution in Darjeeling Himalaya of India. This attempt is the first step to correct taxonomic identification to workout currently accepted botanical names with ecological status, voucher specimen numbers, habitat, altitudinal ranges, phenology and local and general distribution of Herminium species in the regions. For the assessment of present ecological status, plot of 5mx5m quadrates was laid down diagonally in the field for terrestrial orchid species. Of them, three are sparse and the rest two are rare status in the region. June to October is the main flowering seasons of these species. It is found that the diversity and distribution frequency of Herminium species is rich and widespread throughout the Darjeeling Himalaya.
GENETIC DIVERSITY RESOURCES, DISTRIBUTION AND PRESENT ECOLOGICAL STATUS OF FIFTEEN NEW RECORDS OF ORCHID SPECIES TO ASSAM OF EASTERN HIMALAYA
Khyanjeet Gogoi1, R. L. Borah2, G. C. Sharma3 and Rajendra Yonzone4
Bioscience Discovery , 2012,
Abstract: Present paper deals 15 Orchid species with 12 genera viz., Bryobium pudicum, Bulbophyllum apodum, Chrysoglossum ornatum, Cleisostoma linearilobatum, C. simondii, Collabium chinense, Diploprora championii, Eria connate, E. ferruginea, Taeniophyllum crepidiforme, Tainia wrayana, Thelasis pygmaea, Thrixspermum acuminatissimum, T. pygmaeum, and Z. glandulosa were recorded from Dibrugarh district of Assam of Eastern Himalaya for the first time and reported as new distributional records to the state. Out of 15 species 11 species are epiphytic and the rest 4 are terrestrial in habitat. All the species are enumerated with latest citation, brief description, phonology, present ecological status and local distribution within Assam.
Occurrence of Cymbidium mosaic and Odontoglossum ringspot viruses in orchid germplasm of Sikkim and Darjeeling hills, their identification and diagnosis  [cached]
R.P. PANT1*, MRINAL DAS1, K.B. PUN2, P. RAMACHANDRAN3 and R.P. MEDHI1
Indian Phytopathology , 2011,
Abstract: Survey was conducted in Sikkim and Darjeeling hills for orchid viruses during 2007-08. Samples showing different kind of symptoms were collected and maintained in polyhouse at National Research Centre for Orchids, Pakyong, Sikkim. Electron microscopy of negatively stained preparations showed both Cymbidium mosaic (CymMV) and Odontoglossum ringspot (ORSV) viruses from different species. Viruses from EM and ELISA positive samples were mechanically transmitted to various herbaceous hosts. CymMV was successfully transmitted to Datura stramonium and Chenopodium amaranticolor. However, ORSV was mechanically transmitted to Nicotiana benthamiana and Gomphrena globosa. EM and ELISA results revealed that CymMV and ORSV were commonly found in mixed infections causing severe damage to host plants. Both the viruses are highly contagious, stable, found in very high concentration in host tissue and being spread mainly by contaminated tools.
Distribution pattern of the epiphytic orchid Rhynchostylis retusa under strong human influence in Kathmandu valley, Nepal  [PDF]
Yagya Prasad Adhikari,Anton Fischer
Botanica Orientalis: Journal of Plant Science , 2011, DOI: 10.3126/botor.v8i0.5956
Abstract: We studied distribution pattern of the epiphytic orchid Rhynchostylis retusa (L.) Blume with respect to (i) site characteristics and host conditions, and (ii) the type and intensity of land use in Kathmandu Valley, central Nepal. We established a 1.5 km grid net and analyzed epiphytic orchids at each point, searching for 10 trees as close as possible to the grid point. There we analyzed bark water-holding capacity, bark pH, bark roughness and light intensity. We assessed the probability of the occurrence of R. retusa in different land use patterns. Our results indicated that R. retusa was not a host-specific orchid species. It was found on different host tree species. However, Ficus religiosa was the most common host species. The correlation between R. retusa occurrence and microclimate condition was weak. R. retusa , to a certain degree, preferred light intensity of 40-80% of full sun light, rough bark with pH around 6.5 and bark with a wide range of water holding capacity. The distribution pattern of R. retusa was influenced by certain types of land use. The probability to find R. retusa was highest in forest patches and parks and lowest in agricultural and dense populated area. The study reveals that to improve the population size of R. retusa , trees (mainly Alnus nepalensis, Ficus religiosa and Schima wallichii ) should be planted in areas where the orchid species is recently missing. doi: http://dx.doi.org/10.3126/botor.v8i0.5956 Botanica Orientalis – Journal of Plant Science (2011) 8: 90-99
Analysis of epiphytic orchid diversity and its host tree at three gradient of altitudes in Mount Lawu, Java  [PDF]
NINA DWI YULIA,SUGENG BUDIHARTA,TITUT YULISTYARINI
Biodiversitas , 2011,
Abstract: Yulia ND, Budiharta S, Yulistyarini T (2011) Analysis of epiphytic orchid diversity and its host tree at three gradient of altitudes in Mount Lawu, Java. Biodiversitas 12: 225-228. The aim of this study was to observe epiphytic orchid diversity and their host trees at three different altitudes (1796, 1922 and 2041 m asl) at southern part of Mount Lawu, District of Magetan, East Java. Line transect of 10 x 100 m was set up and then divided into ten plots (as replicates) of 10 x 10 m. At each plot, species name and number of individual of epiphytic orchids, and species name, number of individual and diameter at breast height (dbh) of host trees were recorded. The result showed that there were 19 species of epiphytic orchid recorded at the study sites. There were significantly different among gradient altitude in number of epiphytic orchid species (F = 3.7; df = (2, 27); P < 0.05). The highest number of species of epiphytic orchid was recorded at the altitude of 1922 m asl (6.6 species/100 m2) while the highest number of individual was recorded at the altitude of 1796 m asl (1337.7 individuals/100 m2). The study site at altitude of 1922 m asl was recognized as the denser and richer in species of host trees (2.3 species/100 m2 and 3.5 individuals/100 m2 respectively). However, the highest basal area of host tree was recorded at the altitude of 2041 m asl (4558 cm2/100 m2).
Effects of light stress on the growth of the epiphytic orchid Cattleya forbesii Lindl. X Laelia tenebrosa Rolfe
STANCATO, GIULIO C.;MAZZAFERA, PAULO;BUCKERIDGE, MARCOS S.;
Brazilian Journal of Botany , 2002, DOI: 10.1590/S0100-84042002000200011
Abstract: considering the performance of cam epiphytes under high levels of radiation or in shaded environments, with growth rate proportional to light intensity, the objective of this work was to evaluate the effects of long-term light stress on the growth of a brazilian epiphytic orchid, cattleya forbesii lindl. x laelia tenebrosa rolfe. two groups of plants were used in the first experiment, one under 90% (@ 1,650 μmol.m-2.s-1) of photosynthetically active radiation (par) and the other maintained under 22.5% (@ 400 μmol.m-2.s-1). in the second experiment the diffusive resistance, transpiration rate and fluorescence levels were monitored for plants that were under 22.5% of par, under 90% and plants transferred from 22.5 to 90%. our results show that light intensity interfered with growth and development of this orchid. data on the changes in pseudobulb volume throughout the time course of growth suggest that water and reserves stored in the back shoots are translocated to the current shoot. regarding stomatal resistance, plants under 22.5% of par reached a largest stomatal aperture during the night, whereas those under 90% only after dawn. after transfer from 22.5% par to 90% par the ratio of fv/fm decreased from approximately 0.8 to 0.7. this suggests the limitation of photoprotection mechanisms in the leaf and the results observed after the transfer of plants from 22.5% to 90% reinforce the possibility that a photoinhibition is reflected in a decrease in growth rate.
Effects of light stress on the growth of the epiphytic orchid Cattleya forbesii Lindl. X Laelia tenebrosa Rolfe
STANCATO GIULIO C.,MAZZAFERA PAULO,BUCKERIDGE MARCOS S.
Brazilian Journal of Botany , 2002,
Abstract: Considering the performance of CAM epiphytes under high levels of radiation or in shaded environments, with growth rate proportional to light intensity, the objective of this work was to evaluate the effects of long-term light stress on the growth of a Brazilian epiphytic orchid, Cattleya forbesii Lindl. X Laelia tenebrosa Rolfe. Two groups of plants were used in the first experiment, one under 90% (@ 1,650 μmol.m-2.s-1) of Photosynthetically Active Radiation (PAR) and the other maintained under 22.5% (@ 400 μmol.m-2.s-1). In the second experiment the diffusive resistance, transpiration rate and fluorescence levels were monitored for plants that were under 22.5% of PAR, under 90% and plants transferred from 22.5 to 90%. Our results show that light intensity interfered with growth and development of this orchid. Data on the changes in pseudobulb volume throughout the time course of growth suggest that water and reserves stored in the back shoots are translocated to the current shoot. Regarding stomatal resistance, plants under 22.5% of PAR reached a largest stomatal aperture during the night, whereas those under 90% only after dawn. After transfer from 22.5% PAR to 90% PAR the ratio of Fv/Fm decreased from approximately 0.8 to 0.7. This suggests the limitation of photoprotection mechanisms in the leaf and the results observed after the transfer of plants from 22.5% to 90% reinforce the possibility that a photoinhibition is reflected in a decrease in growth rate.
Evidence for Isolation-by-Habitat among Populations of an Epiphytic Orchid Species on a Small Oceanic Island  [PDF]
Bertrand Mallet, Florent Martos, Laury Blambert, Thierry Pailler, Laurence Humeau
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0087469
Abstract: Identifying factors that promote population differentiation is of interest for understanding the early stages of speciation. Gene flow among populations inhabiting different environments can be reduced by geographical distance (isolation-by-distance) or by divergent selection resulting from local adaptation (isolation-by-ecology). Few studies have investigated the influence of these factors in small oceanic islands where the influence of geographic distance is expected to be null but where habitat diversity could have a strong effect on population differentiation. In this study, we tested for the spatial divergence of phenotypes (floral morphology and floral scent) and genotypes (microsatellites) among ten populations of Jumellea rossii, an epiphytic orchid endemic to Réunion growing in three different habitats. We found a significant genetic differentiation between populations that is structured by habitat heterogeneity rather than by geographic distance between populations. These results suggest that ecological factors might reduce gene flow among populations located in different habitats. This pattern of isolation-by-habitat may be the result of both isolation-by-ecology by habitat filtering and asynchrony in flowering phenology. Furthermore, data on floral morphology match these findings, with multivariate analysis grouping populations by habitat type but could be only due to phenotypic plasticity. Indeed floral scent compounds were not significantly different between populations indicating that specific plant-pollinator mutualism does not seem to play a major role in the population differentiation of J. rossii. In conclusion, the results from our study emphasize the importance of habitat diversity of small oceanic islands as a factor of population differentiation.
Effects of simulated nitrogen deposition and a stable isotopic assessment for the neotropical epiphytic orchid Laelia speciosa  [PDF]
Edison A. Díaz-álvarez,Roberto Lindig-Cisneros,Casandra Reyes-García,Erick de la Barrera
PeerJ , 2015, DOI: 10.7287/peerj.preprints.771v1
Abstract: The accelerated increase of nitrogen deposition is the third cause of biodiversity loss, as a result of saturation of ecosystems worldwide. The effects of nitrogen deposition on the endemic and endangered neotropical epiphytic orchid, Laelia speciosa, were evaluated via a dose-response experiment and a stable isotopic field assessment for individuals from a city and from an oak forest, in order to evaluate the potential risk facing this orchid, and record the history of the nitrogen deposition of series of consecutive annually produced pseudobulbs. Lower doses of nitrogen of up to 20 kg N ha yr–1 the dose that led to optimal performance of plants, acted as fertilizer. For instance, chlorophyll content and chlorophyll fluorescence (Fv/Fm) peaked at 0.66 ± 0.03 g m-2 and 0.85 ± 0.01, respectively. In contrast, toxic effects were observed at the higher doses of 40 and 80 kg N ha yr–1, leading a decrease of 38% of the chlorophyll content and 23% of the chlorophyll fluorescence. For the field assessment, a tissue nitrogen content of 1.2 ± 0.1% (dry mass basis) for the orchids suggested non-toxic deposition rates both at the city and the oak forest. However, their respective isotopic signatures revealed different sources of N at each site. Indeed, in the oak forest δ15N amounted –3.1 ± 0.3‰, typical of places with low industrial activities, while in the city the δ15N reached 5.6 ± 0.2‰, typical of sites with some degree of industrial and automobile activity. Laelia speciosa would be an adequate bioindicator of nitrogen deposition because its ability to take up nitrogen from the atmosphere while preserving its isotopic signature and showing a clear physiological response to increasing inputs of nitrogen. However, its limited geographical distribution precludes the orchid as an ideal candidate for biomonitoring. Thus other vascular epiphytes should be considered for this purpose.
Epiphytic orchids of Nepal  [PDF]
M Ghimire
Banko Janakari , 2008, DOI: 10.3126/banko.v18i2.2173
Abstract: This paper includes a list of 207 species of epiphytic orchids from Nepal that belong to 49 genera including 5 endemic species (Bulbophyllum ambrosia, Eria baniai, E. nepalensis, Oberonia nepalensis and Pleione coronaria). Phytogeographical distribution along with altitudinal ranges of all of these epiphytic species, phenology of flowering of 199 species and host plant(s) of 148 species have been reported herewith. The aim of this paper is to assess the distribution patterns, host-epiphyte relationship and phenology of flowering of Nepalese epiphytic orchids.
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