1. KAUTIR (Kerala Agricultural University Theses Information and Retrieval)

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    Assessment of diversity in native orchids
    (Department of Floriculture and Landscaping, College of Agriculture, Vellanikkara, 2021) Shuhda Nalakath; Anupama, T V
    A study entitled ‘Assessment of diversity in native orchids’ was conducted in the Department of Floriculture and Landscaping, College of Agriculture, Vellanikkara, from July 2019 to June 2020. The objective of the study was to assess the diversity among the native orchid accessions by evaluating their morphological characters. The morphological characters of twenty three native orchid accessions conserved under the Department of Floriculture and Landscaping were studied. Based on the growth habit, five accessions were classified as monopodial orchids and 18 accessions were classified as sympodial orchids. The accessions viz; Acampe praemorsa, Aerides crispa, Rhynchostylis retusa, Vanda thwaitesii and Luisia sp. were grouped under monopodials, and the accessions belonging to genera viz; Dendrobium, Eria, Pholidota, Bulbophyllum, Flickingeria, Coelogyne, Cymbidium and Oberonia were grouped under sympodials. The quantitative vegetative characters varied significantly among the accessions. Among the monopodial accessions, Acampe praemorsa (VKA/NOR-3) recorded maximum plant height (43.36 cm), internodal length (2.40 cm), leaf length (23.94 cm), leaf width (2.76 cm) and leaf sheath length (3.60 cm). In sympodial orchid accessions, plant height recorded was highest for Dendrobium moschatum (VKA/NOR-37) (75.20 cm). The highest plant spread was observed in Luisia sp. (VKA/NOR-7) (1571.28 sq.cm) among monopodials, whereas Dendrobium crumenatum (VKA/NOR-34) (3979.22 sq.cm) was superior in terms of this parameter among the sympodials. These two species also recorded maximum number of leaves compared to other accessions (89.20 and 95.80). Among sympodials, Cymbidium accessions were observed to be superior in terms of the parameter leaf length, and maximum leaf length was recorded in Cymbidium ensifolium (VKA/NOR- 43) (43.50 cm). Variability was also noted among the accessions with regard to qualitative vegetative characters viz; leaf shape, leaf orientation, leaf arrangement and root colour. Nine native orchid accessions bloomed during the study period were evaluated for their floral characters. Among them Dendrobium crumenatum (VKA/NOR-34) exhibited three flowering seasons (April-May, October, Dec-Jan). The accessionPholidota imbricata (VKA/NOR-29) recorded highest spike length as well as rachis length (49.66 cm and 23.50 cm). The number of florets per spike recorded was maximum in Rhynchostylis retusa (VKA/NOR-4) (99.33). Largest showy flower among the accessions was observed in Dendrobium moschatum (VKA/NOR-37) with maximum flower size of 54.37 sq.cm, highest petal length (3.98 cm), petal width (2.94 cm), petal to petal distance (6.89 cm), length of dorsal sepal (3.49 cm), width of dorsal sepal (1.63 cm), and length of lateral sepal (3.01 cm). Lip (labellum) is the most attractive feature of an orchid flower and is found to have variations. The accession Dendrobium crumenatum (VKA/NOR-34) (2.75 cm) was found to have maximum lip (labellum) length and Dendrobium moschatum (VKA/NOR-37) (2.28 cm) was found to have maximum lip (labellum) width. The longevity of spike on plant recorded was maximum for Dendrobium ovatum (VKA/NOR-60) (12.00 days), and the longevity of florets on spike recorded was maximum in Acampe praemorsa (VKA/NOR-3) (19.00 days). The pollen viability (%) was found to be more than 90 percentage for all the accessions flowered and it was noted maximum for Rhynchostylis retusa (VKA/NOR- 4) (98.27 percentage). Cluster analysis at 75 percentage similarity among the accessions done based on their quantitative characters resulted in different clusters containing accessions with similar morphological traits. Among sympodials most of the accessions were grouped under Cluster A with common characters for plant spread as well as leaf width. With respect to quantitative floral characters most of the accessions were grouped under Cluster A and they showed similarity for characters such as number of spikes, flower size, petal length and width, petal to petal distance, dorsal sepal to lip distance, length and width of lateral sepal and dorsal sepal, and also length and width of lip and column. Wide variation was observed in spike orientation, petal shape, petal curvature and lip shape. The accessions were also noted for the presence of flower fragrance, and it was recorded in Dendrobium crumenatum (VKA/NOR-34), Dendrobium fimbriatum (VKA/NOR-27), Dendrobium moschatum (VKA/NOR-37), Acampe praemorsa (VKA/NOR-3), Rhynchostylis retusa (VKA/NOR-4) and Eria fragrans (VKA/NOR- 25). The floral parts of the accessions also exhibited different sepal, petal, lip and column colouration.Based on morphological evaluation, superior accessions were identified for commercial traits and accordingly they were grouped as pot plant types (VKA/NOR-4, VKA/NOR-39, VKA/NOR-29), fragrant flowered types (VKA/NOR-27, VKA/NOR- 34, VKA/NOR-37, VKA/NOR-4, VKA/NOR-3) accessions with long spike (VKA/NOR-4, VKA/NOR-29), greater number of florets (VKA/NOR-4, VKA/NOR- 29) and highest longevity (VKA/NOR-29, VKA/NOR-3). Diversity assessment using cluster analysis has revealed the variability as well as similarity existed among native orchid accessions on the basis of their morphological characters. The findings are highly useful for identification of superior accessions which can be utilized for crop improvement programmes and also for commercial floriculture.
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    Performance of selected orchids under varying light regimes, culture methods and nutrition
    (Department of Horticulture, College of Agriculture, Vellayani, 1996) Sabina George Thekkayam; Mohanakumaran, N
    The present study was undertaken to evolve agrotechniques for cut flower orchid production in Kerala. Two experiments were conducted at the College of Agriculture, Vellayani in 1991 and 1992 with two popular cut flower varieties namely Arachnis Maggie Oei ‘Red Ribbon’ and Dendrobium Sonia – 16. The effects of varying light intensities and nutrient regimes under two methods of cultivation were assessed in Arachnis Maggie Oei ‘Red Ribbon’ (Experiment 1) and in Dendrobium Sonia -16, the performance under varying light intensities and nutrient regimes was evaluated (Experiment 2) In Arachnis Maggie Oei ‘Red Ribbon’, trench culture was found to promote growth, flowering and the floral attributes. The number of leaves, aerial roots, leaf area and plant height were greater in the trench grown plants. The number of inflorescences produced, their branching, length and vase life were also enhanced under trench culture. The effect of light intensities on growth was mediated through interactions with culture methods and nutrients. The trench grown plants under 50 and 75 percent light had a greater number of leaves and leaf area. The plants receiving 500 ppm of P and K under 100 percent light had a shorter stature. The direct effect and interactions of nutrients on growth were observed at certain months during the experimental period which was indicative of differences in the requirement at different stages of growth. The dry matter content of the stem and apical shoot was greater in the plants receiving 500 ppm P. Inflorescence production and the vase life of inflorescences was greater under 100 and 75 percent light. Branching of inflorescences was greater under 75 percent light. In Dendrobium Sonia -16 the number of inflorescences produced was greatest under 75 percent light. The length of the inflorescences was greater under 75 percent light and the span area of the flowers was greater under 50 and 75 percent light. Nitrogen at 500 ppm increased the length of the inflorescences, the number of flowers in an inflorescence, and the span area of the flowers. The number of inflorescences produced was also greater in the plants receiving 400 or 500 ppm N, 400 or 500 ppm K and in those receiving 500 ppm P. Interactions between the nutrients and between light intensities and the nutrients were also observed. The nutrient composition of the leaves in both the cultivars were enhanced by the 400 and 500 ppm doses of N and P and 500ppm K. Based on the observed effects, in Arachnis Maggie Oei ‘Red Ribbon’, trench culture of plants under 75 to 100 percent light and a nutrient dosage of 300 ppm N, 400 ppm P and 300 ppm K from planting till nine MAP and thereafter a dosage of 400 to 500 ppm N, 400ppm, P and 500 ppm K can be recommended. In Dendrobium Sonia -16 growing in pots under 75 percent light with 400 to 500 ppm of N, P and K can be recommended
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    Isolation and Characterization of cDNA encoding chalcone synthase from flower buds of orchid Dendrobium variety sonia 17
    (Department of Plant Biotechnology, College of Agriculture,Vellayani, 2007) Anjana, G R; Soni, K B
    The study entitled “Isolation and characterization of cDNA encoding chalcone synthase gene from the flower buds of orchid Dendrobium variety Sonia 17” was conducted at the Department of Plant Biotechnology, Vellayani, Thiruvananthapuram during the period from 2005 to 2007 with an objective of studying the isolation and characterization of cDNA encoding chalcone synthase gene involved in anthocyanin pigmentation in orchid flower buds. . Heterologous forward and reverse primers were designed based on the gene sequences of Oryza sativa, Fragaria ananasa and Phalaneopsis orchid using primer3 software. Total RNA was isolated from immature floral tissues using hot phenol method which gave an yield of 80 - 200 μg g -1 of the tissue and a A260/A280 ratio ranging between 1.6 –2.0. Messenger RNA was purified from the total RNA using the mRNA purification kit from GENEI (Bangalore). Reverse transcription-polymerase chain reaction was carried out to study the expression of gene. The RT-PCR amplified products representing chalcone synthase (CHS) gene was eluted and purified. The product was sequenced and studied the similarity of the same using homology search. All sequenced regions were subjected to BLASTN and BLASTX similarity search. Rice chalcone synthase specific primer produced an amplified sequence of 460 bp long and showed maximum similarity to the cDNA clone 5', mRNA sequence of. flower bud of Phalaenopsis violacea and flower bud of Phalaenopsis equestris Lambda ZapII cDNA Library in BLASTN similarity search.BLASTX analysis of the sequence showed similarity to maturase K protein of Aerangis kirki. The cDNA amplified with strawberry chs specific primer showed maximum similarity to the cDNA clone 5’, mRNA sequence of Phalaenopsis violacea flower bud and flower bud of Phalaenopsis equestris in the BLASTN similarity search. BLASTX analysis of the sequence showed similarity to LFY-like protein of Serapias lingua. The results of the nucleotide to nucleotide search (BLASTN) of the cDNA of orchid, amplified using chalcone synthase specific primer from orchid showed similarity to cDNA 5', mRNA sequence of Ipomoea batatas in the BLASTN similarity search. BLASTX analysis of the sequence showed similarity to retrotransposon protein of Oryza sativa (japonica cultivar-group). The result of the sequences obtained from the study shows similarity with the genes involved in the biosynthetic pathway of Phalaenopsis orchid flower fragrance.
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    Intra and inter generic hybridization and molecular charatrization in monopodial orchids
    (Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2008) Beena Thomas; Lekha Rani, C
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    Response of Ascocenda orchid to growth regulator and micronutrients
    (Department of Floriculture and Landscaping, College of Horticulture, Vellanikkara, 2019) Jesabel George; Shobhana, A
    A study entitled ‘Response of Ascocenda orchid to growth regulator and micronutrients’ was carried out at Department of Floriculture and Landscaping, College of Horticulture Vellanikkara, from May 2018 to May 2019. Ascocenda is a monopodial, epiphytic, bigeneric hybrid, which is mainly grown as pot plant in hanging baskets using bricks, charcoal, coconut husk pieces etc. as growing media. The objective of the study was to evaluate the influence of foliar application of different micronutrient treatments on growth and yield of Ascocenda orchid. The experiment was conducted with eleven treatments viz., 0.01% zinc + 150 ppm benzyl adenine + PoP (T1), 0.025% zinc + 150 ppm benzyl adenine + PoP (T2), 0.01% manganese + 150 ppm benzyl adenine + PoP (T3), 0.025% manganese + 150 ppm benzyl adenine + PoP (T4), 0.01% boron + 150 ppm benzyl adenine + PoP (T5), 0.025% boron + 150 ppm benzyl adenine + PoP (T6), 0.01% iron + 150 ppm benzyl adenine + PoP (T7), 0.025% iron + 150 ppm benzyl adenine + PoP (T8), 0.01% molybdenum + 150 ppm benzyl adenine + PoP (T9), 0.025% molybdenum + 150 ppm benzyl adenine + PoP (T10), 150 ppm benzyl adenine + PoP (T11 – control). Three month old tissue cultured plants of Ascocenda var. Big Suksamran were used for the study. The micronutrients were applied at fortnightly intervals and benzyl adenine was applied at monthly intervals. Application of NPK (3:1:1) weekly twice @ 0.2% and cow dung slurry (1:5) at monthly intervals was given to all treatments as per PoP recommendation of KAU. Observations were taken at monthly intervals. The results indicated that foliar application of 0.025% manganese along with 150 ppm BA and recommended dose of NPK (T4) was best for improving plant height. The maximum plant height obtained at 12MAP was 8.86 cm. This was followed by T5 (8.81 cm) and T3 (8.63 cm) which were statistically on par with T4. The maximum shoot diameter was observed in T5 (10.20 mm) at 12 MAP which was on par with T4 and T3 (9.96 mm and 9.84 mm respectively). The treatment T3 was superior in terms of leaf characters like leaf length and leaf area up to 7 MAP and thereafter these parameters were highest in treatment T5. However, there was no significant difference between T5 and T3 in terms of leaf length at 12 MAP (16.70 cm and 16.48 cm respectively). The highest leaf area at 12 MAP was observed in T5 (23.17 cm2) followed by T3 (22.73 cm2). Number of leaves and leaf breadth were found highest with the application of 0.01% boron along with 150 ppm BA and recommended dose of NPK. A maximum of 13.69 leaves were observed in T5 at 12MAP. The maximum leaf breadth observed in T5 after 12 months of planting was 1.52 cm, which was closely followed by T3 and T4 (1.51 cm each), and no significant difference between these three treatments could be noticed. Regarding interval of leaf production, only 4 treatments (T3, T4, T5, and T11) could produce the highest number of eight leaves, within a period of 386 days. Among these, T4 took the shortest period of 337.45 days to produce the 8th leaf. T10 produced only five leaves within a period of 386 days. Among the root parameters, highest root length was observed in T3 (0.01% manganese + POP + 150 ppm BA) at 12 MAP (26.59 cm) whereas the treatment T4 (0.025% Mn + PoP + 150 ppm BA) was superior in terms of number of roots and root diameter. The best treatment with respect to number of roots varied during initial months, even though, from 6 MAP onwards, highest number of roots was observed in T4 with a value of 10.28 at 12 MAP. In the case of root diameter, a highest of 2.91 mm was recorded in T4 at 12 MAP, which was on par with T8 (2.86 mm), T3 (2.84 mm) and T5 (2.82 mm). Among the eleven treatments, T3 (Mn 0.01% + PoP + 150ppm BA), T4 (Mn 0.025% + PoP + 150ppm BA), and T5 (B 0.01% + PoP + 150ppm BA)were found to be best for improving the vegetative characters of Ascocenda orchid, while application of Mo @ 0.025% (T10) at fortnightly intervals was inhibitory to the plants in terms of all the vegetative characters studied. The objective of studying the floral and postharvest characters could not be achieved since the plant did not bloom within the period of study.
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    Characterisation and conservation of promising genotypes of orchids from central western ghats
    (Department of Plant Breeding and Genetics,College of Agriculture, Padannakad, 2016) Yusuf Abbas; Sujatha, R
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    Physiological approaches for enhancing the ex vitro establishment of tissue cultured orchid (Phalaenopsis sp.)
    (Department of Plant Physiology, College of Agriculture, Vellayani, 2019) Sayooj, S; Viji, M M
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    Distant hybridization and compatibility studies in wild orchids
    (Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2018) Seeja, G; Arya, K
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    Evaluation of fragrant vandaceous orchids for ornamental traits
    (Department of Floriculture and Landscaping, College of Horticulture, Vellanikkara, 2017) Deepa, T; Geetha, C K
    Twenty five fragrant vandaceous orchids were evaluated in the Department of Floriculture and Landscaping during the period from June 2016 to May 2017 with the objective of classifying them based on aesthetic and economic parameters for commercial exploitation as value added plants. The varieties exhibited wide variation in both vegetative and floral characters. Considering quantitative characters, Vasco Crownfox Red Gem recorded the maximum plant height (68.73cm), spread (52.23cm), internodal length (1.95cm) and leaf length (33.83cm). V. Pranerm Prai x V. tessellata showed maximum shoot girth (4.99cm), leaf area (105.54cm2), leaf number (37) and root length (181.75cm). The least values for all these characters were for Neostylis Lou Sneary. Duration from spike emergence to opening of florets was the maximum in Ascda Peggy Foo x Rhyn. Coelestis Blue and minimum in Neostylis Lou Sneary. Maximum spike longevity was recorded in V. Rothschildiana (29.30 days) whereas it was minimum in Rhy Sri Siam x Rhy gigantia (7.50 days). Interval of spike production was also the longest in Ascda. Peggy Foo x Rhyn. coelestis Blue and the minimum in Rhynchorides Bangkok Sunset. Spike production was the maximum in Neostylis Lou Sneary, followed by Ascda Srichai and Vasco Crownfox Red Gem. The varieties/ hybrids varied with regard to blooming period. The peak flowering was from May to July. Longer spike and rachis were noticed in Aerides quinque Vulnera Rhy. Coelestis. Vasco Blue Bay Pink had the highest number of florets/ spike and the shortest internodal length. Largest flowers were observed in V. Rothschildiana. Petal and labellum of the varieties also exhibited different colour patterns such as uniform, spotted, netted, tessellated and shaded. All the evaluated varieties were fragrant and were categorized based on different notes such as floral, fruity, spicy, green, sweet and miscellaneous. Fragrance was very faint in V. Rothschildiana whereas it was musty in Darwineria Cream Puff. With respect to the post-harvest characters longevity (vase life) was the maximum in V. JVB X Ascda Yip Sum Wah (17.30 days) and individual floret life (8.13 days) in V. Rothschildiana. Colour and pigmentation, texture, shape, pattern and size of florets as well as arrangement of florets on the spike were considered for the visual evaluation of a variety for use as cut flower. Considering the overall qualitative and quantitative attributes, Vascostylis Crownfox Red Gem, Vasco Blue Bay Blue, Rhynchorides Bangkok Sunset, V. Mimi Palmer, V. JVB X Ascda Yip Sum Wah and Vasco Blue Bay Pink were excellent for cut flower production. Plant quality evaluation was done based on fullness, growth and visual appearance, flower colour and pigmentation, spike longevity, shape and arrangement of foliage during the growth period. Fragrance scoring was also done based on intensity and diffusiveness, newness and beautifulness of fragrance. Based on the flowering phenology, four phenophases, namely, November – January, February – April, May – July and August – September were recorded and the varieties were categorized accordingly. Side-runs with different colour combinations were observed within a phenophase. The varieties were also categorized on the basis of flower colour, number of florets/ spike and floret size, longevity of spike on the plant , number of spikes produced / year and fragrance. Considering overall quantitative and qualitative characteristics, the evaluated varieties/ hybrids were categorized for cut flower, indoor and outdoor gardens for commercial exploitation as value added plants. The fragrance also makes it a novelty in landscaping to create a peaceful, relaxing environment.
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    Refinement of nutrient management practices in dendrobium orchids
    (Department of Floriculture and Landscapingp, College of Horticulture, Vellanikkara, 2017) Shilpa, P; Mini Sankar
    Twenty five fragrant vandaceous orchids were evaluated in the Department of Floriculture and Landscaping during the period from June 2016 to May 2017 with the objective of classifying them based on aesthetic and economic parameters for commercial exploitation as value added plants. The varieties exhibited wide variation in both vegetative and floral characters. Considering quantitative characters, Vasco Crownfox Red Gem recorded the maximum plant height (68.73cm), spread (52.23cm), internodal length (1.95cm) and leaf length (33.83cm). V. Pranerm Prai x V. tessellata showed maximum shoot girth (4.99cm), leaf area (105.54cm2), leaf number (37) and root length (181.75cm). The least values for all these characters were for Neostylis Lou Sneary. Duration from spike emergence to opening of florets was the maximum in Ascda Peggy Foo x Rhyn. Coelestis Blue and minimum in Neostylis Lou Sneary. Maximum spike longevity was recorded in V. Rothschildiana (29.30 days) whereas it was minimum in Rhy Sri Siam x Rhy gigantia (7.50 days). Interval of spike production was also the longest in Ascda. Peggy Foo x Rhyn. coelestis Blue and the minimum in Rhynchorides Bangkok Sunset. Spike production was the maximum in Neostylis Lou Sneary, followed by Ascda Srichai and Vasco Crownfox Red Gem. The varieties/ hybrids varied with regard to blooming period. The peak flowering was from May to July. Longer spike and rachis were noticed in Aerides quinque Vulnera Rhy. Coelestis. Vasco Blue Bay Pink had the highest number of florets/ spike and the shortest internodal length. Largest flowers were observed in V. Rothschildiana. Petal and labellum of the varieties also exhibited different colour patterns such as uniform, spotted, netted, tessellated and shaded. All the evaluated varieties were fragrant and were categorized based on different notes such as floral, fruity, spicy, green, sweet and miscellaneous. Fragrance was very faint in V. Rothschildiana whereas it was musty in Darwineria Cream Puff. With respect to the post-harvest characters longevity (vase life) was the maximum in V. JVB X Ascda Yip Sum Wah (17.30 days) and individual floret life (8.13 days) in V. Rothschildiana. Colour and pigmentation, texture, shape, pattern and size of florets as well as arrangement of florets on the spike were considered for the visual evaluation of a variety for use as cut flower. Considering the overall qualitative and quantitative attributes, Vascostylis Crownfox Red Gem, Vasco Blue Bay Blue, Rhynchorides Bangkok Sunset, V. Mimi Palmer, V. JVB X Ascda Yip Sum Wah and Vasco Blue Bay Pink were excellent for cut flower production. Plant quality evaluation was done based on fullness, growth and visual appearance, flower colour and pigmentation, spike longevity, shape and arrangement of foliage during the growth period. Fragrance scoring was also done based on intensity and diffusiveness, newness and beautifulness of fragrance. Based on the flowering phenology, four phenophases, namely, November – January, February – April, May – July and August – September were recorded and the varieties were categorized accordingly. Side-runs with different colour combinations were observed within a phenophase. The varieties were also categorized on the basis of flower colour, number of florets/ spike and floret size, longevity of spike on the plant , number of spikes produced / year and fragrance. Considering overall quantitative and qualitative characteristics, the evaluated varieties/ hybrids were categorized for cut flower, indoor and outdoor gardens for commercial exploitation as value added plants. The fragrance also makes it a novelty in landscaping to create a peaceful, relaxing environment.