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S. K. Braman - One of the best experts on this subject based on the ideXlab platform.
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Using Aesthetic Assessments of Azalea Lace Bug (Heteroptera: Tingidae) Feeding Injury to Provide Thresholds for Pest Management Decisions
Journal of Economic Entomology, 2001Co-Authors: W. E. Klingeman, G. D. Buntin, S. K. BramanAbstract:Research on consumer, grower, and landscape manager perception of Azalea lace bug, Stephanitis pyrioides (Scott), feeding and on plant productivity parameters, including gas exchange and growth, has increased our understanding of the nature of feeding injury. These studies made it possible to develop decision-making guidelines for cost-effective maintenance of aesthetically pleasing Azaleas. Criteria were considered for three management situations: a 0.41-ha (1-acre) nursery production system that may use either insecticidal soap, acephate, or imidacloprid to control lace bugs; a landscape planting of a group of 10 Azaleas; or maintenance of a single Azalea in the landscape. Lace bug thresholds were calculated using a hybrid economic injury level (EIL) formula. Pesticide application decisions were determined using survey-based data from grower, landscape manager, and consumer perceptions of unacceptably injured Azaleas at point-of-purchase for the nursery situation. Additional landscape scenarios incorporated the perceptions of growers, landscape managers, and consumers for those levels of lace bug feeding-injury that prompted the desire for treatment. Hybrid EIL determinations are appropriate for lace bug management in landscape systems where landscape professionals manage large plantings of Azaleas and as a component of pest management among nursery production systems. Aesthetic considerations are more appropriate in determining control thresholds among a few or individual Azaleas in the landscape.
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Azalea growth in response to Azalea lace bug (Heteroptera: Tingidae) feeding.
Journal of Economic Entomology, 2001Co-Authors: W. E. Klingeman, S. K. Braman, G. D. BuntinAbstract:The effects of Azalea lace bug, Stephanitis pyrioides (Scott), feeding injury on Azalea growth and development were investigated using ‘Girard’s Rose’ Azaleas during a 2-yr field study in Georgia. Low, medium, and high injury treatments, which corresponded to 6, 8, and 14% maximum canopy area injury, were compared with control Azaleas that received no lace bug infestation. Flower number, whole-shrub leaf and stem dry mass, and dry mass and size of new growth tissues were unaffected by treatments. In contrast, growth index measurements, a general measure of variability frequently used for horticultural differentiation, showed significant reductions for all treatments in comparison to control Azaleas after 20 wk. Though not directly quantified, this apparent discrepancy may be explained as an artifact of lace bug feeding-induced leaf abscission. Growth index measurements had considerable variability and may not be the most reliable measurement of size. In July 1998, plant canopy densities among Azaleas maintained in the high injury treatments were ≈15% less full than the canopies of control shrubs. Predaceous insects had a significant negative association with Azalea lace bug number during the 2-yr study. Flower and new tissue production, measured destructively during two growing seasons, revealed Azalea tolerance to 14% of maximum canopy area lace bug feeding-injury levels.
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Feeding injury of the Azalea lace bug (Heteroptera: Tingidae).
Journal of Entomological Science, 2000Co-Authors: W. E. Klingeman, S. K. Braman, G. D. BuntinAbstract:Azalea lace bug, Stephanitis pyrioides (Scott), feeding rates were investigated in controlled laboratory bioassays. Individual newly-eclosed nymphs were transferred to cut stems of ‘Girard's Rose’ Azaleas and maintained at either 20°C for 26°C for the duration of their lifetimes. Feeding rates, determined using computer assisted image area analysis, were calculated for both nymphs and adults. In both trials, females caused significantly more feeding injury per day than males. However, the overall amount of injury inflicted during lace bug lifetimes was similar for males and females at both temperatures. During adulthood, feeding injury by individual lace bugs resulted in a mean (±SD) of 6.35 ± 4.61 cm2 leaf area injury at 20°C and 3.93 ± 2.06 cm2 leaf area injury at 26°C. Nymphal feeding was a small fraction of the injury inflicted by the adults and averaged 0.43 ±0.15 cm2 at 20°C and 0.30 ±0.10 cm2 at 26°C. The determination of Azalea lace bug feeding-injury potential is critical to the development of de...
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Whole-Plant CO2 Exchange Measurements on Azaleas Injured by Azalea Lace Bug (Heteroptea: Tingidae) Feeding
Journal of Economic Entomology, 2000Co-Authors: W. E. Klingeman, M.w. Van Iersel, G. D. Buntin, S. K. BramanAbstract:Whole-plant gas exchange was measured continuously for 24 h on rooted cuttings of Girard's 'Pleasant White' Azaleas. Azalea treatments were Azalea lace bug, Stephanitis pyrioides (Scott), feeding injury levels that averaged 6, 13, or 31% leaf-area injury throughout the plant canopies. Gas exchange parameters, including net photosynthesis, dark respiration, carbon use efficiency, and growth, were compared with undamaged control plants. Responses of Girard's 'Pleasant White' Azaleas suggested that Azaleas were tolerant of lace bug feeding injury levels above the aesthetic threshold. Azalea tolerance can be incorporated into an integrated management plan to reduce chemical inputs into the urban landscape.
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evaluating grower landscape manager and consumer perceptions of Azalea lace bug heteroptera tingidae feeding injury
Journal of Economic Entomology, 2000Co-Authors: W. E. Klingeman, S. K. Braman, G. D. BuntinAbstract:A survey using modified Azalea stems was used to establish a “tally threshold value” for assessing Azalea lace bug, Stephanitis pyrioides (Scott), feeding injury to Azalea shrubs. Consumers and green-industry professionals, represented by ornamental growers, landscape architects, and landscape managers, recognized Azalea lace bug injury when injured leaf area exceeded 2%. Purchase and treatment decisions of professionals and consumers were evaluated by surveying responses to Rhododendron indica variety alba ‘Delaware Valley White’ Azaleas representing a range of damage. Survey participants also provided a brief biographical background and answers to questions regarding pesticide use, ability to identify diseases, pests, and beneficial organisms, and willingness to consider pesticide alternatives. Professionals and consumers expressed a strong interest in limiting urban pesticide use. The 2 groups indicated a hypothetically acceptable level of 6–10% plant damage by arthropod pests. A 2% injury threshold was used to determine the level of proportional damage (the percentage of leaves displaying 2% or more lace bug leaf feeding injury) resulting in either the rejection of plant purchase or initiation of treatment. A nonlinear curve was fit to treatment and no-purchase responses of professionals and consumers using a modified 3-parameter Mitscherlich nonlinear growth function. Half of the surveyed professionals and consumers indicated that damage proportions >10% (1.03% actual injury) were sufficient to reject an Azalea for purchase. Proportional damage levels >43% (3.3% actual injury) would be necessary to prompt 50% of the respondents to initiate treatment of damaged Azaleas to control lace bugs.
Nobuo Kobayashi - One of the best experts on this subject based on the ideXlab platform.
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Genetic Relationship of Rhododendron ripense Makino to Japanese Evergreen Azalea Cultivars Evaluated by SSR Markers
2020Co-Authors: Nobuo Kobayashi, Kyoko Sugai, Tomoyuki Tsuji, Akira NakatsukaAbstract:Evergreen Azalea cultivars as the important ornamental shrubs and pot plants have been developed based on the genetic resources of Japanese wild Azaleas. Rhododendron ripense Makino is one of the representative wild Azalea species endemic to West Japan and the ancestral parent of evergreen Azalea cultivars. In this study, we focused on this large flowered riverside Azalea and the genetic contribution to Azalea cultivars was evaluated by means of SSR markers. The results of PCoA using SSR data made plot distributions, which would reflect the taxon and genetic relationship between cultivar groups and their ancestral species. All individuals of R. ripense which classified in subsection Scabra makes distribution group apart from R. kaempferi and R. kiusianum group which classified in subsection Tsutsusi. The cultivars of R. ripense, Ryukyu Azalea (R. × mucronatum) and ‘Oomurasaki’ (R. × pulchrum) are all included in this R. ripense plot group. These results of this study suggested the important genetic contribution of R. ripense to the development of these Azalea cultivars.
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Root Characteristics of Cuttings Grown from Evergreen Azaleas
Horticultural Research (japan), 2020Co-Authors: Nobuo Kobayashi, Akira Nakatsuka, Madoka Miyazaki, Fumihiko AdachiAbstract:Varietal differences in root development were evaluated using cuttings of three species and four cultivars of evergreen Azaleas. More than 80% of cuttings were rooted in a shaded rain shelter, a closed–frame and a mist propagation system. Total root lengths of Rhododendron ripense and R. × pulchrum ‘Oomurasaki’ were long, while those of R. indicum ‘Osakaduki’ and Kurume Azalea ‘Kirin’ tended to be short. Leaf number and leaf area of each Azalea were increased in cuttings of shaded rain shelter and closed–frame system, compared to mist propagation system except for the leaf area of R. macrosepalum. R. macrosepalum, R. indicum ‘Osakaduki’ and R. × mucronatum ‘Shiro-ryukyu’ showed a wide rooting areas in the cuttings, having many and a wide range of extended roots out of cylindrical net in the nursery bed. R. kaempferi and Kurume Azalea ‘Kirin’ showed a narrow rooting area, having a small number of roots extending out of the net. These varietal differences of root characteristics in rooted cuttings showed the same tendency as field-planted plants in a previous study and would be related to genetic traits originating from adaptation to the natural habitat environment by each original species and the varieties derived from them. Root characteristics of cuttings from evergreen Azalea can be indicator of the root traits of field plants and would be useful information for application to the breeding of evergreen Azalea.
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Long-lasting Corolla Cultivars in Japanese Azaleas: A Mutant AP3/DEF Homolog Identified in Traditional Azalea Cultivars from More Than 300 Years Ago.
Frontiers in Plant Science, 2018Co-Authors: Kyeong-seong Cheon, Akira Nakatsuka, Keisuke Tasaki, Nobuo KobayashiAbstract:Floral shape in higher plants typically requires genetic regulation through MADS transcription factors. In Japan, hundreds of Azalea cultivars including flower shape mutations have been selected from the diversity of endogenous species and natural hybrids since the early 17th century, the Edo era (1603 to 1867). The long-lasting trait, known as “Misome-shō” in Japanese, has been identified in several species and cultivar groups of evergreen Azaleas (Rhododendron L.) from three hundred years ago in Japan. However, the natural mutation conferring the long-lasting trait in Azalea remains unknown. Here, we showed MADS-box gene mutations in long-lasting flowers, R. kaempferi ‘Nikkō-misome’, R. macrosepalum ‘Kochō-zoroi’, R. indicum ‘Chōjyu-hō’, and R. × hannoense ‘Amagi-beni-chōjyu’. All of the long-lasting flowers exhibited small-sized corollas with stomata during long blooming. In the long-lasting flowers, transcript of the APETALA3 (AP3)/DEFICIENS (DEF) homologue was reduced, and an LTR-retrotransposon was independently inserted into exons 1, 2, and 7 or an unknown sequence in exon 1 in gDNA of each cultivar. This insertion apparently abolished the normal mRNA sequence of the AP3/DEF homologue in long-lasting flowers. Also, long-lasting flowers were shown from F2 hybrids that had homozygous ap3/def alleles. Therefore, we concluded that the loss of function of the AP3/DEF homologue through a transposable element insertion may confer a stable long-lasting mutation in evergreen Azaleas.
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Adaptation to iron deficiency and high pH in evergreen Azaleas (Rhododendron spp.): potential resources for breeding
Euphytica, 2017Co-Authors: Sonia Demasi, Nobuo Kobayashi, Takashi Handa, Matteo Caser, Stefania De Pascale, Valentina ScariotAbstract:The growth of evergreen Azaleas ( Rhododendron spp.) can be altered by iron (Fe) chlorosis when plants are cultivated in a neutral-alkaline substrate. In this study, morphological and physiological responses to alkalinity and Fe deficiency were evaluated in five diploid Japanese Azaleas to assess their potential as resources for breeding. R. obtusum ‘Kirin’, R. indicum ‘Shinsen’, R. × pulchrum ‘Sen-e-oomurasaki’, R. indicum ‘Osakazuki’, and R. ripense were pot cultivated in a peat-based substrate for 10 weeks, in acid and alkaline growing media with both adequate and inadequate Fe nutrition. Plant performance was generally affected by high pH of the substrate, while Fe deficiency by itself influenced few of the evaluated parameters, possibly due to the complex adaptive response mechanisms of these slow growing ornamental shrubs. According to the biochemical and physiological variations recorded on a long period of cultivation, R. indicum ‘Osakazuki’ reported the best performance. This Azalea could be a valuable resource for breeders.
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Hydroponic Screening for Iron Deficiency Tolerance in Evergreen Azaleas
Notulae Botanicae Horti Agrobotanici Cluj-napoca, 2015Co-Authors: Sonia Demasi, Nobuo Kobayashi, Matteo Caser, Yuji Kurashige, Valentina ScariotAbstract:Evergreen Azaleas grow in acid soil and suffer from iron deficiency when cultivated in substrate with pH higher than 6.0. In order to select tolerant plants, 11 Azalea genotypes were tested for 21 days in alkaline solution (pH 9), buffered with sodium hydrogen carbonate (1 g·l -1 ). Leaf damage, root length and mortality rate were recorded. While leaf damage and mortality rate allowed to discriminate genotypes, root development appeared not directly linked to iron deficiency tolerance. Rhododendron ‘Juko’, R. scabrum , R. macrosepalum ‘Hanaguruma’, R. x pulchrum ‘Oomurasaki’, and R. x pulchrum ‘Sen-e-oomurasaki’ resulted iron efficient genetic resources, useful for Azalea cultivation and gardening in calcareous soils. On the contrary, R. obtusum ‘Kirin’, R. tosaense , R. x mucronatum ‘Fujimanyo’ and R. obtusum ‘Susogo-no-ito’ resulted iron deficiency sensitive genotypes. R. x mucronatum ‘Ryukyushibori’ and R. indicum ‘Kinsai’ showed intermediate responses.
G. D. Buntin - One of the best experts on this subject based on the ideXlab platform.
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Using Aesthetic Assessments of Azalea Lace Bug (Heteroptera: Tingidae) Feeding Injury to Provide Thresholds for Pest Management Decisions
Journal of Economic Entomology, 2001Co-Authors: W. E. Klingeman, G. D. Buntin, S. K. BramanAbstract:Research on consumer, grower, and landscape manager perception of Azalea lace bug, Stephanitis pyrioides (Scott), feeding and on plant productivity parameters, including gas exchange and growth, has increased our understanding of the nature of feeding injury. These studies made it possible to develop decision-making guidelines for cost-effective maintenance of aesthetically pleasing Azaleas. Criteria were considered for three management situations: a 0.41-ha (1-acre) nursery production system that may use either insecticidal soap, acephate, or imidacloprid to control lace bugs; a landscape planting of a group of 10 Azaleas; or maintenance of a single Azalea in the landscape. Lace bug thresholds were calculated using a hybrid economic injury level (EIL) formula. Pesticide application decisions were determined using survey-based data from grower, landscape manager, and consumer perceptions of unacceptably injured Azaleas at point-of-purchase for the nursery situation. Additional landscape scenarios incorporated the perceptions of growers, landscape managers, and consumers for those levels of lace bug feeding-injury that prompted the desire for treatment. Hybrid EIL determinations are appropriate for lace bug management in landscape systems where landscape professionals manage large plantings of Azaleas and as a component of pest management among nursery production systems. Aesthetic considerations are more appropriate in determining control thresholds among a few or individual Azaleas in the landscape.
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Azalea growth in response to Azalea lace bug (Heteroptera: Tingidae) feeding.
Journal of Economic Entomology, 2001Co-Authors: W. E. Klingeman, S. K. Braman, G. D. BuntinAbstract:The effects of Azalea lace bug, Stephanitis pyrioides (Scott), feeding injury on Azalea growth and development were investigated using ‘Girard’s Rose’ Azaleas during a 2-yr field study in Georgia. Low, medium, and high injury treatments, which corresponded to 6, 8, and 14% maximum canopy area injury, were compared with control Azaleas that received no lace bug infestation. Flower number, whole-shrub leaf and stem dry mass, and dry mass and size of new growth tissues were unaffected by treatments. In contrast, growth index measurements, a general measure of variability frequently used for horticultural differentiation, showed significant reductions for all treatments in comparison to control Azaleas after 20 wk. Though not directly quantified, this apparent discrepancy may be explained as an artifact of lace bug feeding-induced leaf abscission. Growth index measurements had considerable variability and may not be the most reliable measurement of size. In July 1998, plant canopy densities among Azaleas maintained in the high injury treatments were ≈15% less full than the canopies of control shrubs. Predaceous insects had a significant negative association with Azalea lace bug number during the 2-yr study. Flower and new tissue production, measured destructively during two growing seasons, revealed Azalea tolerance to 14% of maximum canopy area lace bug feeding-injury levels.
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Feeding injury of the Azalea lace bug (Heteroptera: Tingidae).
Journal of Entomological Science, 2000Co-Authors: W. E. Klingeman, S. K. Braman, G. D. BuntinAbstract:Azalea lace bug, Stephanitis pyrioides (Scott), feeding rates were investigated in controlled laboratory bioassays. Individual newly-eclosed nymphs were transferred to cut stems of ‘Girard's Rose’ Azaleas and maintained at either 20°C for 26°C for the duration of their lifetimes. Feeding rates, determined using computer assisted image area analysis, were calculated for both nymphs and adults. In both trials, females caused significantly more feeding injury per day than males. However, the overall amount of injury inflicted during lace bug lifetimes was similar for males and females at both temperatures. During adulthood, feeding injury by individual lace bugs resulted in a mean (±SD) of 6.35 ± 4.61 cm2 leaf area injury at 20°C and 3.93 ± 2.06 cm2 leaf area injury at 26°C. Nymphal feeding was a small fraction of the injury inflicted by the adults and averaged 0.43 ±0.15 cm2 at 20°C and 0.30 ±0.10 cm2 at 26°C. The determination of Azalea lace bug feeding-injury potential is critical to the development of de...
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Whole-Plant CO2 Exchange Measurements on Azaleas Injured by Azalea Lace Bug (Heteroptea: Tingidae) Feeding
Journal of Economic Entomology, 2000Co-Authors: W. E. Klingeman, M.w. Van Iersel, G. D. Buntin, S. K. BramanAbstract:Whole-plant gas exchange was measured continuously for 24 h on rooted cuttings of Girard's 'Pleasant White' Azaleas. Azalea treatments were Azalea lace bug, Stephanitis pyrioides (Scott), feeding injury levels that averaged 6, 13, or 31% leaf-area injury throughout the plant canopies. Gas exchange parameters, including net photosynthesis, dark respiration, carbon use efficiency, and growth, were compared with undamaged control plants. Responses of Girard's 'Pleasant White' Azaleas suggested that Azaleas were tolerant of lace bug feeding injury levels above the aesthetic threshold. Azalea tolerance can be incorporated into an integrated management plan to reduce chemical inputs into the urban landscape.
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evaluating grower landscape manager and consumer perceptions of Azalea lace bug heteroptera tingidae feeding injury
Journal of Economic Entomology, 2000Co-Authors: W. E. Klingeman, S. K. Braman, G. D. BuntinAbstract:A survey using modified Azalea stems was used to establish a “tally threshold value” for assessing Azalea lace bug, Stephanitis pyrioides (Scott), feeding injury to Azalea shrubs. Consumers and green-industry professionals, represented by ornamental growers, landscape architects, and landscape managers, recognized Azalea lace bug injury when injured leaf area exceeded 2%. Purchase and treatment decisions of professionals and consumers were evaluated by surveying responses to Rhododendron indica variety alba ‘Delaware Valley White’ Azaleas representing a range of damage. Survey participants also provided a brief biographical background and answers to questions regarding pesticide use, ability to identify diseases, pests, and beneficial organisms, and willingness to consider pesticide alternatives. Professionals and consumers expressed a strong interest in limiting urban pesticide use. The 2 groups indicated a hypothetically acceptable level of 6–10% plant damage by arthropod pests. A 2% injury threshold was used to determine the level of proportional damage (the percentage of leaves displaying 2% or more lace bug leaf feeding injury) resulting in either the rejection of plant purchase or initiation of treatment. A nonlinear curve was fit to treatment and no-purchase responses of professionals and consumers using a modified 3-parameter Mitscherlich nonlinear growth function. Half of the surveyed professionals and consumers indicated that damage proportions >10% (1.03% actual injury) were sufficient to reject an Azalea for purchase. Proportional damage levels >43% (3.3% actual injury) would be necessary to prompt 50% of the respondents to initiate treatment of damaged Azaleas to control lace bugs.
Erik Van Bockstaele - One of the best experts on this subject based on the ideXlab platform.
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Cryopreservation of Azalea by encapsulation-dehydration
Acta Horticulturae, 2003Co-Authors: Hans Verleysen, Erik Van Bockstaele, G. Samyn, Pierre DeberghAbstract:There is an Azalea collection, with more than 600 accessions, at the Department of Plant Genetics and Breeding. In order to maintain this collection in an efficient and economical way, new preservation strategies are required, and this is the subject of this paper. Preliminary results show the usefulness of an encapsulation-dehydration technique to cryopreserve Azaleas. Shoot tips of in vitro micropropagated plants were precultured on culture medium with high sucrose concentration, subsequently encapsulated (beads contain sucrose and glycerol), dried and frozen by direct immersion in liquid nitrogen. 41.7% of the cryopreserved shoot tips regenerated into fully-grown plants in vitro and in vivo. Further research is needed to evaluate the genetic and epigenetic stability of the regenerated plants. In particular the sporting of cryopreserved material needs further investigation.
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Characterization of carotenoid biosynthesis in Rhododendron luteum
Meded Rijksuniv Gent Fak Landbouwkd Toegep Biol Wet, 2001Co-Authors: Ellen De Keyser, J Dendauw, Jan Riek, Erik Van BockstaeleAbstract:In the color chart of Rhododendron simsii hybrids (Belgian pot Azalea), yellow is not yet present, although this color is wanted by growers and consumers. Carotenoid pigments, which are absent in Azalea, are responsible for this yellow color of the flower petals. The first objective of this project is characterizing the pathway of carotenoid biosynthesis in the yellow flowers of Rhododendron luteum.
Ellen De Keyser - One of the best experts on this subject based on the ideXlab platform.
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The use of relative quantitative RT-PCR for expression analysis in Azalea flower color sports.
Communications in agricultural and applied biological sciences, 2020Co-Authors: Ellen De Keyser, Jan Riek, Erik Van BockstaeleAbstract:The fastest way to create new Azalea (Rhododendron simsii hybrids) cultivars is by making use of flower colour sports, which appear spontaneously on Azalea plants. Unfortunately, there is still very little known on how bud sport induction occurs. Therefore, genes coding for two key enzymes of the Azalea flavonoid biosynthesis pathway, chalcon synthase (chs) and dihydroflavonol 4-reductase (dfr) that were reported before to be apt for modification by the action of bud sporting, were isolated and characterized. The expression of these two flower colour genes in the petals of Azalea flowers will be compared between all 'Hellmut Vogel' flower colour sports. To measure the expression levels of both genes, relative quantitative RT-PCR analysis will be worked out on a real-time PCR machine. The expression of housekeeping genes, which is expected to be the same for all sports, will be used to calculate the relative expression level of the two genes of interest. The optimisation of this technique will be discussed.
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Azalea phylogeny reconstructed by means of molecular techniques
Methods of Molecular Biology, 2010Co-Authors: Ellen De Keyser, Nobuo Kobayashi, Valentina Scariot, Takashi Handa, Jan RiekAbstract:: Plants belonging to the Rhododendron subgenera Pentanthera (deciduous) and Tsutsusi and Azaleastrum (evergreen) are called Azaleas. Concerning their mutual phylogenetic positions, the Pentanthera subgenus is closer to evergreen rhododendrons (subgenera Rhododendron and Hymenanthes) than to the Tsutsusi subgenus. Both Azalea types are important ornamentals with a long breeding tradition. Different hybrid groups are often named after the supposed principal ancestor species. Molecular techniques for phylogenetic and kinship research have been evaluated to a great extent. First, some studies using comparative gene sequencing are presented; this approach was then widened to the use of molecular markers to reveal more detailed genetic relationships. Finally, the use of candidate genes as functional markers for the assessment of genetic diversity is presented. This opens new research lines to the genetic mapping of plant traits and Azalea genomics.
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Optimisation of Relative Quantitative RT-PCR for Expression Analysis in Azalea Flower Colour Sports
Acta Horticulturae, 2004Co-Authors: Ellen De Keyser, Jan Riek, Erik Van BockstaeleAbstract:The fastest way to create new Azalea (Rhododendron simsii hybrids) cultivars is by making use of flower colour sports, which appear spontaneously on Azalea plants. Unfortunately, there is still very little known on how bud sport induction occurs. Therefore, genes coding for two key enzymes of the Azalea flavonoid biosynthesis pathway, chalcon synthase (chs) and dihydroflavonol 4-reductase (dfr) that were reported before to be apt for modification by the action of bud sporting, were isolated and characterized. The expression of these two flower colour genes in the petals of Azalea flowers will be compared between all ‘Hellmut Vogel’ flower colour sports. To measure the expression levels of both genes, relative quantitative RT-PCR analysis will be worked out on a real-time PCR machine. The expression of housekeeping genes, which is expected to be the same for all sports, will be used to calculate the relative expression level of the two genes of interest. The optimisation of this technique will be discussed.
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Characterization of carotenoid biosynthesis in Rhododendron luteum
Meded Rijksuniv Gent Fak Landbouwkd Toegep Biol Wet, 2001Co-Authors: Ellen De Keyser, J Dendauw, Jan Riek, Erik Van BockstaeleAbstract:In the color chart of Rhododendron simsii hybrids (Belgian pot Azalea), yellow is not yet present, although this color is wanted by growers and consumers. Carotenoid pigments, which are absent in Azalea, are responsible for this yellow color of the flower petals. The first objective of this project is characterizing the pathway of carotenoid biosynthesis in the yellow flowers of Rhododendron luteum.