Available online freely at www.isisn.org Bioscience Research Print ISSN: 1811-9506 Online ISSN: 2218-3973 Journal by Innovative Scientific Information & Services Network REVIEW ARTICLE BIOSCIENCE RESEARCH, 2017 14(3): 558-565. OPEN ACCESS Physiological stresses and phyto-hormones: Effects on the flowering process and longevity of bougainvillea Mohammad Saifuddin1, Mohammad Moneruzzaman Khandaker2 Majrashi Ali Abdullah3 Khairil Mahmud2 and Mohammad Hailmi Sajili2 1 Institute of Biological Sciences, Faculty of Science, University of Malaya, 50603, Kuala Lumpur, Malaysia School of Agriculture Science & Biotechnology, Faculty of Bioresources and Food Industry, Universiti Sultan Zainal Abidin, Besut Campus, 22200 Besut, Terengganu, Malaysia 3 Department of Biological Science, Faculty of Science, Taif University, Taif, Saudi Arabia. 2 .*Correspondence: moneruzzaman@unisza.edu.my.Accepted: 19 June. 2017 Published online: 30 Sep. 2017 A wide variety trait of Bougainvillea genus has made it a decent potential as a new ornamental plant. Different type of foliage, many inflorescence, continuous bloom, first growing and short production cycle of bougainvillea plants that make them attractive to the floriculture industry. Therefore, the longevity of flowers and leaves are crucial nowadays. Apart from the external appearance, the length of their vaselife has become one of the most important criteria in evaluating their quality. Petal colour and its variations also regulate the acceptance of flowers in high competitive flower market. Several researches have been carried out throughout the world on how to improve flower size, petal colour, flower bloom cycle and flower longevity. Many horticultural techniques have been conducted for different flowering and ornamental plants but there is very few literatures are found on flower quality and longevity of bougainvillea. Therefore, few methods such as physiological stresses and phyto-hormone spraying to enhance plant growth, development, flowering process and longevity of bougainvillea have been discussed in this review article Keywords: Bougainvillea, Pruning, Phyto-hormone, Flowering process, Longevity INTRODUCTION Bougainvillea is a flowering plant genus which belongs to the family of Nyctaginaceae and native in South America (Saifuddin et al. 2010). Suxia et al. (2009) reported that bougainvillea have eighteen species and all the species generally used in beautification for the arid landscapes, agriculture, horticulture, environmental industries and pharmaceutical industries, on account of the large flexibility in different agro climatic regions of the world. Recently, it has been reported that bougainvillea is a pollution tolerant plant and can help in the mitigation of air pollution causes of greenhouse gases. Therefore, bougainvillea plants are recommended to planting in urban and industrial areas where the air and sound pollution is very high. The plant can easily adapt to various growing condition and it can be planted in polluted soil, central verge, traffic island, and various other industrial and ecotourism places (Kulshreshtha et al. 2009). As its massive scope, introduction and variation of bract color and size are highly preferable. It has been stated that environmental factors revealing seasonal changes and create significant effect to control the flowering (Ana et al. 2004). Intensity of light, day length, temperature, nutrient Saifuddin et al. Horticultural techniques on quality of Bougainvillea availability and stress are the most important environmental factors that influence the flowering of plants. With regards to light, the quality, quantity and duration are all important variables that can regulate the flowering. Stirling et al. (2002) reported that temperatures are perceived in different parts of the plant during the control of flowering photoperiod. Some other besides environmental factors, has been found to stimulate flowering or frequent flowering such as plant growth regulators, growth promoting chemicals, removal of young leaves, girdling, pruning, dwarfing and different stress (Saifuddin et al. 2009a). Recently, it has been stated that the foliar spray of 1-Triacontanol stimulates growth, enhances flowering, and improves the quality of potted Bougainvillea plants (Khandaker et al. 2013) In most experiments, the best results have been achieved with application of GA3 mixture along with some additional treatments, girdling, root pruning, fertilization and water stress (Saifuddin et al. 2009a). Physiological stresses on plants life and flower Initiation: Impact of pruning on plants life Pruning can be used to improve tree shape, to influence its growth, flowering and fruitfulness, to improve fruit quality, to repair injury, to contain the plant and to increase light and spray penetration (Jean et al. 2007). The ultimate goal of pruning is to improve light distribution so that more tree canopies would maintain high quality flowers and fruits production. In recent years, flower growers and pomologists have been interested in pruning as a mean of growth control when dwarfing rootstocks do not adequately control tree size. Bougainvillea plants respond well to pruning. The shoots of the plants grow vigorously that why regular pruning and thinning is necessary to shape and direct the plant growth. Kent et al. (2007) reported that pruning should be carried out immediately after flowering because pruning promote the new growth which next flush of flowers would occur. It has been reported that pruning stimulated many metabolic sinks that may cause depletion of reserved carbohydrates flowing from lower plant parts to the new developing flower buds (Salakpetch et al. 1990). Low carbohydrate content was adequate to stimulate the new flowering shoots in both pruned and non-pruned plants. It was also reported that pruned plants have a higher turgor than the non-pruned plants. An offset benefit of a smaller canopy might be the reduced canopy of water consumption and improved tree water status due to a lower canopy transpiration. A reduction in canopy leaf area whether occurs naturally or artificially by pruning, was expected to raise new leaf, soil water potentials and reduce loss of water (Khan et al. 1998). Flowering ornamental plant bougainvillea can be pruned at any time of the year. Initiation of flower depends upon pruning of the plant and bud formation cycle followed by a certain period after pruned. In winter season, a hard pruning is recommended to prepare the plant for indoor condition. For maintain continuous blooming of bougainvillea need to do soft pruning. Gordon (2002) reported that vine type bougainvillea plant continue to grow outward without sending out side branches from each leaf-bud point unless the stem is pinched. Johnson et al. (1993) stated that flowering and vegetative growth of plant can be modified by training and pruning. Pruning also regulated the position of flower with regard to vegetative growth, e.g. heading cuts may Delaying Flower Drop Flower longevity or vase life is the most important character that affects the commercial value of flowers or other ornamental plants (Saifuddin et al. 2009b). Commercial value of flowers could be improved by lengthening the longevity of flower and improving its quality in such as petal color and size (Tjosvold et al. 1994). Vase life of flower is related to petal and leaf senescence, and it is caused by rapid production of ethylene after harvesting from the mother plant (Serek et al. 2006). Sometimes, microbial infection, bacterial colonization and air embolisms also affect the vase life of flowers. Application of GA3 and ethylene inhibitor hormone NAA individually or its combination in low concentration at the different developing stages, flowering time and transported periods increased the longevity of flowers (Hye and William, 2009). Therefore, the effect of hormone spray, pruning and shading on the plant growth, flowering process as well as biochemical and physiological changes of bougainvillea plant need to be discussed to promote flower size and delay flowers drop. The objectives of this review paper are to discuss the flowering process and consequently its appreciable longevity by applying physiological stresses and phyto-hormones. Bioscience Research, 2017 volume 14(3): 558-565 559 Saifuddin et al. Horticultural techniques on quality of Bougainvillea dissociate flowering from vegetative parts by stimulate vegetative growth in the outer canopy of the tree and enhanced flower bud formation in inner canopy (Calatayud et al. 2002). This might have deleterious effects on flowers and fruits quality. Figure 1. Different type of girdling or phloemic stress affect flowering behaviour of plant (Adopted from Khandaker et al. 2012) Impact of phloemic stress on plants life There are so many horticultural techniques that are involved in making dwarfed trees. Partially ringed bark strip is an important technique among them. Ringing or removal of bark as is a horticultural practice used to manipulate tree physiology, growth, and fruit formation in a variety of fruit species. Dwarfed, compact, or small size trees provide for easier pruning, thinning, spraying, fertilizer application, control of insect pest, harvesting, quality fruit and less cost of production. It has been reported that phloemic stress treatments decreased the vegetative growth and increase the flowering in mango (Jose, 1997). A higher trunk circumference above the girdle may be caused by swelling of the trunk due to the accumulation of carbohydrates (Onguso et al. 2004). They also reported that ringing or phloemic stress blocked the translocation of sucrose from leaf to root through the phloem bundles. However, in unfavorable condition a severe girdling from the stems killed the plants and partial phloemic stress weakened the plants growth and development. Khandaker et al. (2012) reported that different types of girdling or phloemic stress improve the quality of plant parts by increasing colour and accumulation of dry matter in leaf, flower and fruits. Bark ringing tended to dwarf the tree, induced flower bud formation, and promoted fruiting in peach trees (Hossain, 2006). It has been also reported that girdling applied before flowering enhanced inflorescence development and quality of fruits (Khandaker et al. 2011). Hormonal effects on Bougainvillea: Impacts of GA3 Gibberellic acid (GA3) application also has the potential to control vegetative growth, flowering and enhance earliness. GA3 treatment increased length of petiole and leaf area of strawberry. Several researcher reported that application of GA3 stimulate flowering in a wide range of plant species. Many species that flower early in response to both GA3 and long days or vernalization, raising the possibility that GA3 may be involved in these responses. This response to exogenous GA3 is paralleled to the effect of photoperiod and vernalization on GA3 metabolism. Gibberellins played a role in floral initiation and development. The buds on the upper surface of the tuber uptake more gibberellin than the other surfaces. At higher gibberellin concentration and treatment duration increased the proportion of shoots that initiated inflorescences. It has been reported that gibberellin increased in the proportion of initiated flowers that subsequently emerged and the proportion of axillary buds that initiated flowers. It was also found that the percentage of changed flower colors was altered in the subsequent clonal generation vis-à-vis the effect also diminished with the passage of time. GA plus Bioscience Research, 2017 volume 14(3): 558-565 560 Saifuddin et al. Horticultural techniques on quality of Bougainvillea kinetin also had a significant effect on improving flower longevity at the mature (fully colored) bud, but produced a lesser effect when applied to green immature buds. It has been reported that sucrose and kinetin application increased flower quality and increased the vase life and Bougainvillea flower (Moneruzzaman et al. 2010a) S.No 1 Growth regulators GA3 Effects References 2 GA3 3 GA3 Development of stamens and petals during flower development and expansion Reduced the time needed for flower emergence, promote flowering and increased the number of flower buds and bloom flowers Stimulated more rapid flowering Saifuddin et al. 2009a 4 GA3 Increase the number and size of flower 5 GA3 Sharma and Room, 2009 Brooking and Cohen, 2002. Ogale et al. 2000 Enhanced the early flowering and decreased the Xingjun et al. 2003 number of leaf 6 GA3 Blooming rate of Bougainvillea Khandaker et al. 2015 7 GA3 Increased hydrolysis of starch and sucrose into Fernfindez et al. 1997 glucose and fructose which are utilized by flowers for opening of disc floret. 8 Kinetin Increased flower bud formation and improved the Moneruzzaman et al. longevity of Bougainvillea flower 2010b 9 1-Triacontanol Stimulate the flowering and increased the size of Khandaker et al. 2013 Bougainvillea bract 10 GA3 Increased the flowering, fruit formation and Moneruzzaman et al. colour development 2011a Table 1: Effects of growth regulators on flower formation, flower quality and longevity Figure 2: Effect of different concentration GA3 on blooming rate of Bougainvillea (Adopted from Khandaker et al. 2015) Bioscience Research, 2017 volume 14(3): 558-565 561 Saifuddin et al. Horticultural techniques on quality of Bougainvillea Figure 3: Effect of different concentration GA3 on bract size of Bougainvillea (Adopted from Khandaker et al. 2015) also one of the natural occuring plant growth Flower composed of several floral parts, is a regulatory substances (PGRS) or famously known heterogonous organ and all this floral part are in as phytohormones (Bleecker and Kende, 2000). different physiological stages. Gibberellin present This simplest carbon atom compound is a at different concentrations in different floral parts dominant regulator of plant growth, metabolism, of same flower. It has been reported that GA3 and interacting with other plant growth regulators significantly increased the number of disc florets in trace amounts. Ethylene is the key but decreased the dry matter content in flower phytohormone in promoting senescence in cut heads and stems. flowers and causes fruit ripening. This directly It also been reported that removal of young leaf reduces quality and display life of flowers. and cytokinin treatment promote the flower bud Ethylene was a natural plant product where it development and increased the bract quality of could induce senescence in plants. Ethylene also Bougainvillea (Moneruzzaman et al. 2010b). play a significant role in regulating the physical, Turgidity maintenance is an important technique biochemical and cellular changes that constitute in lengthening of shelf life of gerbera cut flowers. the post-pollination syndrome in Phalaeopsis Xingjun et al. (2003) reported that carbohydrates (Beatriz and James, 2008). It acts by inhibiting content and dry weight of petals are decline at the respiration, decreasing cell wall material and final stages of flower development. Besides lipids, and increasing sugar levels of the plants. In horticultural techniques, genetic and general, it appears to hasten senescence plant environmental factors also affect the flowering organs and accelerate the abscission process behavior of several ornamental plants (Redman et al. 2002). (Moneruzzaman et al. 2011) Investigation by other researchers also proved Emongor (2004) stated that gibberellins that ethylene production increased during flower increase hydrolysis of starch and sucrose into senescence and ethylene accelerates flower glucose and fructose, which were utilized by the senescence (Celikel et al. 2002). It is devidid into flowers for floret opening and expansion of petal. three phases which corresponds to the three Naphthalene Acetic Acid in presence of GA3 phases of senescence. The first phases is the delayed bract abscission and color fading of pre-climacteric phase, the concentration of bougainvillea bract because of increased the ethyene metabolized by the tissues is extremely a hydrolysis of TSS by GA3 which delayed petal little and the respiration rate is a stable (Kosugi et senescence and color fading. Zhu and Davies al. 2000). Ethylene production occurus in all plant (1997) stated that may be NAA to interact with organs including flower but the magnitude of its GA3 and hence delaying the abscission of flower production varies and depends of growth and by either delaying the natural rise in ethylene development process. Recent scientific process production or by altering the sensitivity of the has made clear the understanding of biosynthetic tissue to ethylene or both. pathway and enzymes involment in ethylene Ethylene effects on flowers longevity production (Kenza et al. 2000).This autocatalytic effect of ethylene could be very pronouced and A number of developmental factors regulate the lead to loss of quality during transporation and ethylene production and it can be induced by storage (Van Door, 2001). The vase life of many physiological, chemical and environmental bougainvillea flowers could be extended by silver stressess during germination, growth, senescence thiosulfate (STS), an inhibitor of ethylene action of leaf and flowers and ripening of fruits. Besides (Chang and Chen, 2001). Their findings acting as a plant hormone influencing many suggested that ethylene regulated sepal aspects of plant growth and development, it is Bioscience Research, 2017 volume 14(3): 558-565 562 Saifuddin et al. Horticultural techniques on quality of Bougainvillea abscission in bougainvillea. Patterson and Bleecker (2004) reported that abscission is a typical ethylene response that is alleged by ethylene receptors and is regulated by mutations in ethylene receptor genes. Flower longevity is one of the most important traits of ornamental plants and the lengthening of longevity is an ongoing target for plant breeders and horticulturist (Onozaki et al. 2001). pattern were discussed on Bougainvillea spp. It can be concluded based on the current research review, soft frequent pruning is the effective methods to induce frequent flowering and prolong vase life of bougainvillea bract. Exogenous applications of GA3 increase bract size and prolong the vase life of Bougainvillea. Synthetic auxin- NAA as ethylene inhibitor For preventing the deteriorative effect of ethylene on postharvest behavior of ornamental plants a range of methods and chemicals is used. Interfering with the plant response to ethylene can be achieved by inhibition of plants own ethylene production inhibition, blocking the binding of ethylene to its receptor and blocking the plant’s reaction to the binding of ethylene to the receptor. Common used chemical is silver thiosulfate (STS) but its toxicity is high. Now, another chemical, naphthalene acetic acid (NAA) is mostly used due to its low toxicity level (Dimitrios et al. 2008). It has been reported that leaf chlorophyll content, net photosynthetic rate and drymatter content of wax apple plant leaves increased significantly with NAA application (Khandaker et al. 2015). All of these improved physiological activities play a significant role to promote flowering and longevity in the plant. Foliar application of NAA increased the flowering and fruit number of tomato plants. Khandaker et al. (2017) reported that application of 25 mg/L NAA improved the plant physiological activities and stimulate flowering as well as flower number of Mokara Chark Kuan orchid flowers. Normanly (1997) reported that the regulatory effects of plant hormone depend on the stage of plant development. NAA treatments also prevent the sprouting of stems and bulb of ornamental plants. Chang and Chen (2001) reported that application NAA at the cut tip of ornamental plants suppressed the growth of lateral bud and this adaption is manipulated to cultivate beautiful ornamental plants. CONCLUSION Growth manipulating techniques are being constantly changed and improved to meet the demands of individual species and cultivars of flowering plants. Each flowering plant needs a specific approach, and at the same time it should be as simple as possible. In this current research, the effect of growth regulators such as gibberellic acid (GA3) and NAA and the plant manipulation tactic by heading pruning to improve the flowering CONFLICT OF INTEREST The authors declared that present study was performed and published in absence of any conflict of interest. ACKNOWLEGEMENT The authors thank to Research Management, Innovation & Commercialization Centre (RMIC) Universiti Sultan Zainal Abidin (UniSZA), Terengganu, Malaysia for publication support AUTHOR CONTRIBUTIONS Designed the review paper MS and MMK. Wrote the paper MS and MMK. Reviewed and edited the paper KM and MHS. All authors read and approved the final version. Copyrights: © 2017 @ author (s). This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, prvided the original author(s) and source are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms. REFERENCES Ana PAV, Rita CL, Figueiredo R, Gilberto BK (2004). Photoperiod and temperature effects on in vitro growth and flowering of P. pusilla, an epiphytic orchid. Plant Physiol Biochem. 42: 411-415. Beatriz C, James JG (2008). Molecular biology of ethylene during tomato fruit development and maturation. Plant Sci. 175(1-2):106-113. Bleecker AB, Kende H (2000). Ethylene: a gaseous signal molecule in plants. Ann Rev Cell Dev Biol. 16: 1-18. Brooking IR, Cohen D (2002). Gibberellin-induced flowering in small tubers of Zantedeschia ‘Black Magic’. Sci Hort. 95: 63-73. Calatayud A, Ramirez JW, Iglesias DJ, Barreno E (2002). Effects of ozone on photosynthetic CO2 exchange, chlorophyll a fluorescence Bioscience Research, 2017 volume 14(3): 558-565 563 Saifuddin et al. Horticultural techniques on quality of Bougainvillea and antioxidant systems in lettuce leaves. Physiol Plant. 116: 308–316. Celikel FG, Dodge LL, Reid M (2002). Effect of 1MCP and promalin for extending the postharvest life of oriental lilies (Lilies x Mona Lisa and Stargazer). Sci Hort. 93: 149-155. Chang YS, Chen HC (2001). Variability between silver thiosulfate and 1- naphthaleneacetic acid applications in prolonging bract longevity of potted bougainvillea. Sci Hort. 87: 217-224. Dimitrios PN, Tzanetos IC, Georgia PN, Nikos P (2008). Portable sensor for the rapid detection of naphthalene acetic acid in fruits and vegetables using stabilized in air lipid films with incorporated auxin-binding protein 1 receptor. Talanta, 77: 786-792. Emongor VE (2004). Effect of gibberellic acid on postharvest quality and vase life of gerbera cut flowers (Gerbera jamesonii). J Agron. 3: 191-195. Fernfindez JA, Banon S, Franco JA, Gonzfilez A, Martinez PF (1997). Effects of verbalization and exogenous gibberellins on curd induction and carbohydrate levels in the apex of cauliflower (Brassica oleracea vat. botrytis). Sci Hort. 70: 223-230. Gordon B (2002). Bougainvillea tutorial, www.askmar.com/Bougainvilleas/ Bougainvilleas. Hossain ABMS (2006). Dwarfing peach trees grafted on vigorous rootstock by summer pruning and partial ringing”, PhD. Thesis, Ehime University, Japan. Jean S, Pierre-Eric L, Nicolas D, Nicolas H, Salma T, Herve S (2007). Architecture of the pruned tree: impact of contrasted pruning procedures over 2 years on shoot demography and spatial distribution of leaf area in apple (Malus domestica). Ann Bot. 99: 1055-1065. Johnson GN, Young AJ, Scholes JD, Horton P (1993). The dissipation of excess excitation energy in British plant species. Plant Cell Environ. 16: 673-679. Jose A (1997). Effect of girdling treatments on flowering and production of mango. Acta Hort. 455:132-134. Kenza M, Umiel N, Borochov A (2000). The involvement of ethylene in the senescence of ranunculus cut flowers. Postharvest Biol Technol. 19: 287-290. Khan ZU, McNeil DL, Samad A (1998). Root pruning reduces the vegetative and reproductive growth of apple trees growing under an ultra high density planting system. Sci Hort.77: 165-176. Khandaker MM, Faruq G, Rahman MM, SofianAzirun M, Boyce AN (2013). The Influence of 1-Triacontanol on the Growth, Flowering, and Quality of Potted Bougainvillea Plants (Bougainvillea glabra var. ‘‘Elizabeth Angus’’) under Natural Conditions. Sci World J, 2013:1-12. Khandaker MM, Hossain AS, Osman N, Boyce AN (2011). Application of girdling for improved fruit retention, yield and fruit quality in Syzygium samarangense under field conditions. Int J Agril Biol. 13: 18-24 Khandaker MM, Hossain AS, Osman N, Boyce AN (2012). Effects of the Phloemic Stress on the Growth, Development and Quality of Wax Apple (Syzygium samarangense) cv. Jambu madu. Sains Malaysiana, 41(5): 553–560. Khandaker MM, Hossain AS, Osman N, Nashriyah M, Boyce AN (2015). Growth, Yield and Postharvest quality of Wax Apple as Affected by Naphthalene Acetic Acid Application. Rev Brasil Fruticul. 37(2): 410422. Khandaker MM, Rosnah Jamaludin, Nur Naeimah and Amru Nasrulhaq Boyce, 2015. The Influence of Gibberellic Acid (GA3) and Sucrose on Flowering Behaviour of Bougainvillea glabra Under Natural Conditions. Aus J Basic Applied Sci, 9(31): 423-429 Khandaker MM, Zuraini M, Naeimah NN, Nashriyah M (2017). Effects of Naphthalene Acetic Acid (NAA) on the Plant Growth and Sugars Effects on the Cut Flowers Mokara Chark Kuan Orchid. Biosci J, 33(1):19-30. Kosugi Y, Shibuya K, Tsuruno N, Iwazaki Y, Mochizuki A, Yoshioka T, Hashib T, Satoh S (2000). Express of gene responsible for ethylene production and wilting are differently regulated in carnation (Dianthus caryophyllus L.) petals. Plant Sci. 158: 139-145. Moneruzzaman KM, Al-Saif AM, Alebedi AI, Hossain ABMS, Normaniza O, Boyce AN (2011). Nutritional quality evaluation of three cultivars of Syzygium samaragense under Malaysian conditions. Afr J Agril Res. 6 (3):545-552. Moneruzzaman KM, Hossain ABMS, Normaniza O and Boyce AN, 2011a. Growth, yield and quality responses to gibberellic acid (GA3) of Wax apple Syzygium samarangense var. Jambu air madu fruits grown under field conditions. Afr J Biotechnol 10(56): 1191111918 Moneruzzaman KM, Hossain ABMS, Normaniza Bioscience Research, 2017 volume 14(3): 558-565 564 Saifuddin et al. Horticultural techniques on quality of Bougainvillea O, Saifudin M, Sani W, Amru NB (2010b). Effects of removal of young leaves and cytokinin on inflorescence development and bract enlargement in Bougainvilea glabra var. "Elizabeth Angus". Aus J Crop Sci. 4 (7): 467473. Moneruzzaman KM, Hossain ABMS, Saifuddin M, Imdadul H, Normaniza O, Amru NB (2010a). Effects of sucrose and kinetin on the quality and vase life of Bougainvillea glabra Var. Elizabeth angus bracts at different temperature. Aus J Crop Sci. 4(7): 474-479. Normanly J (1997). Auxin metabolism. Physiology Plantarum, 100: 431-442. Ogale VK, Babu PV, Mishra SD (2000). GAinduced stage specific changes in flower color and size of portulaca grandiflora cv NL-CRyP. Current Sci. 79: 889-894. Onguso JM, Mizutani F, Hossain ABMS (2004). Effects of partial ringing and heating of trunk on shoot growth and fruit quality of peach trees. Bot Bull Acad Sin. 45: 301-306. Onozaki T, Ikeda H, Yamaguchi T (2001). Genetic improvement of vase life of carnation flowers by crossing and selection. Sci Hort. 87: 107120. Patterson SE, Bleecker AB (2004). Ethylenedependent and -independent processes associated with floral organ abscission in Arabidopsis. Plant Physiol. 134:194-203. Redman PB, Dole JM, Maness NO, Anderson JA (2002). Postharvest handling of nine speciality cut flower species. Sci Hort. 92:293-303. Saifuddin M, Hossain ABMS, Normaniza O, Moneruzzaman KM (2009a). Bract size enlargement and longevity of Bougainvillea spectabilis as affected by GA3 and phloemic stress. Asian J Plant Sci. 8: 212‐217. Saifuddin M, Hossain ABMS, Normaniza O, Nasrulhaq BA, Moneruzzaman KM (2009b). The effects of naphthaleneacetic acid and gibberellic acid in prolonging bract longevity and delaying discoloration of Bougainvillea spectabilis. Biotechnol. 8: 343-350. Saifuddin M, Hossain ABMS, Osman N (2010). Impacts of shading on flower formation and longevity, leaf chlorophyll and growth of Bougainville glabra. Asian J Plant Sci. 9(1): 20-27. Salakpetch S, Turner DW, Dell B (1990). The flowering of carambola (Averrhoa carambola L.) is more strongly influenced by cultivar and water stress than by diurnal temperature variation and photoperiod. Sci Hort. 43: 83-94. Serek M, Woltering EJ, Sisler EC, Frello S, Sriskandarajah S (2006). Controlling ethylene responses in flowers at the receptor level. Biotechnology Advances, 24: 368-381. Sharma RR, Room S (2009). Gibberellic acid influences the production of malformed and button berries, and fruit yield and quality in strawberry (Fragaria × ananassa Duch.). Sci Hort. 119: 430-433. Stirling KJ, Clark RJ, Brown PH, Wilson SJ (2002). Effect of photoperiod on flower bud initiation and development in myoga (Zingiber mioga Roscoe). Sci Hort. 95: 261–268. Suxia X, Qingyun H, Qingyan S, Chun C, Brady AV (2009). Reproductive organography of Bougainvillea spectabilis Willd. Sci Hort. 120:399-405. Tjosvold SA, Wu MJ, Reid MS (1994). Reduction of postproduction quality loss in potted miniature roses. Hort Sci. 29: 293-294. Van Doorn WG (2001). Categories of petal senescence and abscission: a reevaluation. Ann Bot. 87: 447-56. Xingjun L, Sanyu L, JinXing L (2003). Effect of GA3 spraying on lignin and auxin contents and the correlated enzyme activities in bayberry (Myrica rubra Bieb.) during flower bud induction. Plant Sci. 164: 549-556. Zhu YX, Davies PJ (1997). The control of apical bud growth and senescence by auxin and gibberellin in genetic lines of pea. Plant Physiol. 113:631-637. Bioscience Research, 2017 volume 14(3): 558-565 565