Research Journal of. Environmental Sciences ISSN

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1 Research Journal of Environmental Sciences ISSN

2 Research Journal of Environmental Sciences 9 (5): , 2015 ISSN / DOI: /rjes Academic Journals Inc. Effects of Amino Oxyacetic Acid (AOA) and Sucrose on the Longevity of Bougainvillea Flower Bract A.B.M. Sharif Hossain Department of Biology, Faculty of Science, Hail University, Hail, Kingdom of Saudi Arabia ABSTRACT Bougainvillea is a popular ornamental plant in the tropics and sub-tropics of the world. It bursts forth with colorful flowers for the year round if it is planted in the adaptive climate. The ornamental importance of Bougainvillea bract is for the imparting and increasing color effect in the garden. Increasing plantation and beautification of bougainvillea have a scope in drier region and its use in vacant areas as road side plantation, beautification of traffic islands and wide road dividers for its own colorful environment. The study was carried out to investigate the effects of Amino Oxyacetic Acid (AOA) and sucrose on the vase life and senescence of bougainvillea bract. The treatments were used as water control, AOA and sucrose at different concentrations. The decreasing trend of fresh weight was found on the 3rd day and again increased on the 5th day in the case of all treated flowers. The lowest water uptake percentage was found in 4% sucrose and 50 ppm AOA concentration. However, senescence was delayed for 3 days in AOA 50 ppm and 4% sucrose concentration. The vase life of both AOA 50 ppm and 4% sucrose concentration treated-flowers were much longer (4 days) than control compared to the all concentration of sucrose and AOA. The results showed that the best treatment for vase life and delay senescence was AOA 50 ppm and 4% sucrose concentration. Key words: AOA, bougainvillea, sucrose, senescence, vase life INTRODUCTION Bougainvilleas are popular ornamental plants and used as landscape and official flowers in most areas with warm climates, including Australia, India, Malaysia, the Mediterranean region, Mexico, South Africa, Taiwan and the United States in Arizona, California, Florida, Hawaii and southern Texas (Hossain et al., 2008). It had been reported that Bougainvillea was used to decorate fences and arbors with explosions of color in the house corridor, office and play ground. A Bougainvillea tree could make guarding the entry or framing a window. Bougainvillea was a great vine for large containers to decorate hot patios and plazas. Bougainvillea was also used to create beautiful flowering bonsai specimens (Hossain et al., 2008). They also reported that bougainvillea was prime importance for horticulture, as well as potentially for pharmaceutical industries, agriculture and environmental industries. The bougainvillea plant is mainly grown for its attractive bracts in wide array of colors which splash color to the surrounding where it grows. Wide adaptability to different climatic conditions and simple multiplication has made them a popular ornamental plant in the world. The mass effect of the colorful bracts of bougainvillea can alter the face of any given place in a magnificent way which could not be achieved by punctuating any other plant. The flowering of bougainvillea is compared with other flowing plants of temperate countries and very truly called as Glory of the Tropics (Roy, 1998). 206

3 Senescence and longevity are an important issue for cut flower for commercial purpose. Senescence in a number of different cut flowers (e.g., roses, carnation, Petunia and various orchids) is accompanied by a sudden increase in their endogenous ethylene production (Goh et al., 1985). The initial symptom of senescence was either wilting or abscission, but in some species the time span between wilting and abscission was very short (Woltering and van Doorn, 1988). The potential for plant growth regulators to regulate senescence is becoming apparent. Some studies think that the senescence signal is hormone-like substance that travels from fruit to the leaves and other vegetative parts where it triggers senescence (Nickell, 1982). Aminooxyacetic Acid (AOA) is one of the ethylene inhibitors. These ethylene inhibitors such as Amino-ethoxy Vinyl Glycine (AVG) and Silver Thiosulphate (STS) effectively delayed senescence of climacteric flowers by inhibiting the synthesis or action of 1-aminocyclopropane-1carboxylate synthase (ACCS) (Yang and Hoffman, 1984). Aminooxyacetic Acid (AOA), an ethylene synthesis, has been shown to have effect on Dendrobium Jew Yuay Tew flowers. Ketsa and Narkbua (2001) reported that cut roses held in all concentrations of AOA plus 5% sucrose had significantly longer vase life than the control or sucrose alone but their vase life was not significantly different among all concentrations of AOA. In another experiment, a pretreatment with Aminooxyacetic Acid (AOA) was able to delay coloration of the labellum of individual cut Cymbidium flowers and to increase longevity (Harkema and Struijlaart, 2008). Aminooxyacteic Acid (AOA) also has been made to effectively delayed petal wilting in carnations and was already used by the growers supplying the flower auctions in Holland (Van Doorn and Woltering, 1991). A few literature was found related to this research, therefore, the research was undertaken to investigate the effect of sucrose and AOA on the bougainvillea bract longevity and senescence. MATERIALS AND METHODS The experiment was conducted in the Biotechnology laboratory at the Institute of Biological Science, University of Malaya, Kuala Lumpur, Malaysia. Plant material: The flowers were harvested from the orchard at the Institute of Biological Science, University of Malaya. Six years old Bougainvillea glabra trees were used in this experiment at University Malaya orchard, Kuala Lumpur, Malaysaia. Total of 12 trees was selected for the experiments. Six trees for experiment 1 (sucrose concentration) and other 6 trees for experiment 2 (AOA concentration). The bracts (flower) were collected from the experiment site. Flowers were harvested randomly. Treatment setting: The treatments were set following randomized completely blocked design and each treatment was repeated by 3 replications. Total of 27 flowers was collected for 9 treatments. In storage condition, bougainvillea bracts (flower) were placed in distilled water for control and solution containing 2, 3, 4 and 5% sucrose for experiment 1. For the AOA, the bracts were placed in distilled water for control and solution containing 25, 50 and 100 ppm AOA for experiment 2. Experiment 1 Parameter of sucrose concentration Fresh weight and water uptake measurement: Fresh weight was measured immediately after harvesting the bracts. Dry weight was measured after all flowers were abscised. The weight of each bract was measured per day using the digital weighing machine. The difference between 207

4 consecutive weights of bract was used to calculate as water uptake. Evaporated water loss from the surface of the solution was negligible. The weight of each flower was estimated by measuring the bracts and flowers for 5 days. From this, it can be determined the water uptake of the plants. Evaluation of vase life of bracts: Vase life of flower was observed by counting the day. Bract status was observed every day. The observation was done until the bract was abscised or reached the end of their longevity. Evaluation of senescence of bracts: Petal senescence was determined using the percent of the bract get senescence. More it gets senescence, more the percentage. It was recorded by observing it on day 1st until it became senescence. Evaluation of bracts discoloration: For the petal discoloration, color changing (petal discolor) was determined by visual observation every day. If no color changing occurred, it gave the 0% result. The more color changing occur, more increase the percentage. Experiment 2: Same Parameters were used for experiment 2 as experiment 1. RESULTS AND DISCUSSION Experiment 1: The water uptake of the flower was different while using the different treatments. Generally, all the treatments showed weight increment in the first two days and began to decrease thereafter. On the day 3, water uptake was no longer effective to increase the fresh weight of the flowers and the weight began to drop. On day 3, the water uptake decreased and it increased again when the flower was undergone senescence. On the 5th day, the water uptake was higher at 2% sucrose and lower at 4% sucrose concentration treated flowers (Fig. 1). In the Fig. 2 above illustrated that 4% sucrose was the most effective in prolonging the vase life of flowers to 4 days, followed by 3% of sucrose solution which could extend the vase life of flower to 3.5 days. It showed that, the best concentration was the 4% of sucrose solution because it could increase the vase life of flowers and the longevity of the flower. In Fig. 3 it showed that the flowers color remain the same on 1st day. From the 3rd day, the flower discoloration showed increment until the 5th days. On the 5th day, the least discoloration was found at 4% sucrose treated flower (45.00±13.23%). The less discoloration showed the more longevity for the flowers could achieve. Water uptake (g) % 3% 4% 5% Fig. 1: Water uptake for Bougainvillea glabra flowers. Mean±SE (n = 3) 208

5 s Sucrose concentration (%) 3.0 Fig. 2: Vase life for distilled water (control), 2% sucrose, 3% sucrose, 4% sucrose and 5% sucrose treated flowers. Mean±SE (n = 3) Percentage % 3% 4% 5% 1st 3rd 5th Fig. 3: Discoloration of colors for Bougainvillea glabra Percentage % 3% 4% 5% st 3rd 5th Fig. 4: Senescence rate at different concentration of sucrose treated flowers As shown in Fig. 4, the senescence of bracts for every treated flower increased through the days. Senescence rate for 2% sucrose treated flower was recorded as 91.67±1.67% which was slightly higher than senescence rate for 5% sucrose treated flower (86.67±8.82%) and 3% sucrose treated flowers (78.33±14.24%). The senescence rate for 4% sucrose treated flower was the least among the 209

6 (a) Sucrose 2% Sucrose 3% S uc rose 4% Sucrose 5% (b) C ontrol Sucrose 2% Sucrose 3% Sucrose 4% Sucrose 5% Fig. 5(a-b): (a) Appearance of the flowers at different treatments on 1st day and (b) Appearance of the flowers on 5th day other treatment (66.67±10.14%), it showed that until day 5, the senescence still not completely occurred on this treatment. As shown in Fig. 5a, every treated flower was fresh and exhibited bright purple color on the day of experiment. However, as can be seen in Fig. 5b on the fifth day of experiment, all of the treated flowers except 4% sucrose treated flower has been shrink and loss many of the color. 210

7 Water uptake (g) st 3rd 5th 25 ppm 50 ppm 100 ppm Fig. 6: Water uptake of Bougainvillea glabra flowers s AOA concentration (ppm) Fig. 7: Vase life at different concentrations of AOA treated flower. Mean±SE (n = 3) Experiment 2 Aminooxyacetic acid concentration: Figure 6 showed that the best Aminooxyacetic Acid (AOA) was 50 ppm concentration. It was similar to the results obtained from sucrose. In the 1st days, the 50 ppm AOA treated flower showed the highest weight. Then in the following day, the water uptake decreased ( ± g) and increased again. This was due to the flowers did undergo senescence, it was needed more water to prolong their life. For the AOA, the Fig. 7 showed that the 50 ppm AOA gave the best results in vase life of flower which was 4 days while the shortest vase life was demonstrated by the 25 ppm AOA which was 2.5 days. In the Fig. 8 showed that on the 1st day, all the treatment gave zero discoloration. Then, on the 3rd days, some of discolorations occurred. The highest discoloration was water control treated flowers and the least was 50 ppm AOA treated flowers. Figure 9 showed that on the 1st day, the senescence rate for all of the treatment was 0%. Then, it slightly increased on day 3 for all of the treatment, where distilled water (control) treated flower senescence rate was 98%, 25 ppm AOA treated flower was 90%, 100 ppm AOA treated flower was 85% and the least 50 ppm AOA was 73%. On the 5th day, the highest senescence rate showed in the 25 ppm AOA (95.00±0.00%), followed by control (99.33±0.67) and 100 ppm AOA (86.67±8.82). The 50 ppm AOA do not showed any increment. Therefore, the optimum concentration was 50 ppm AOA. 211

8 Percentage ppm 50 ppm 100 ppm 1st 3rd 5th Fig. 8: Discoloration for Bougainvillea glabra ppm 50 ppm 100 ppm Percentage st 3rd 5th Fig. 9: Senescence rate in AOA treated flowers over a period of five days For the different AOA concentration, the treated flowers also exhibited bright and purple color on the day of experiment as shown in the Fig. 10a. On the fifth day of experiment as shown in the Fig. 10b, senescence symptoms could be seen clearly in the in flowers held in distilled water (control), 25 ppm AOA and 100 ppm AOA whereas, 50 ppm AOA treated flowers exhibited only exhibited small discoloration and wilting characteristics. Thus from my observation, 50 ppm AOA proved to be the best treatment, as after 5 days of incubation of the flowers exhibited the least senescence symptoms. In the experiment it has been emphasized the longevity of bougainvillea because of its attractive bracts in wide array of color which splash color to the surrounding where it grows (Roy, 1998). In the results, it has been shown that the longevity of bougainvillea flowers was increased by sucrose and AOA concentration. Yakimova et al. (1996) also showed that the longevity of cut spray-carnation flowers was effectively retarded when treated with AOA. The use of sugars (sucrose) in holding solution of cut flowers has been extensively studied and has yielded a great amount of success in a variety of cultivars. It also has a negative effect on the process of cell death leading to petal senescence (Chandran et al., 2006). Among the different types of sugars, sucrose has been found to be the most commonly used sugar in prolonging the vase life of cut flowers Nichols (1973). In this study of morphological changes for different sucrose concentration treated flowers over period of five days, showed that flowers held in 4% Sucrose holding solution delayed senescence and exhibited the least senescence symptoms such as discoloration and 212

9 (a) AOA 25 ppm AOA 50 ppm AOA 100 ppm (b) AOA 25 ppm AOA 50 ppm AOA 100 ppm Fig. 10(a-b): (a) Appearance of flowers on 1st day and (b) Appearance of flowers on 5th day wilting (Fig. 5a-b). It showed that the flowers that treated with 4% Sucrose also had longer vase life compared to the other treatment. Zuliana et al. (2008) reported that 4 and 2% sucrose were able to increase the vase life of pollinated Dendrobium Pompadour flowers. In contrast, flower treated with distilled water (control) exhibited the earliest senescence symptoms compared to the other different concentration of Sucrose treated flower. By observation, 4% Sucrose proved to be the best treatment to delay the senescence of the Bougainvillea glabra flower followed by 3% sucrose. However, studies by Cho et al. (2001) and reported that providing a vase solution with at least 3% sugar had a very significant effect on flower life and flower quality. Metabolic sugars play a crucial role in maintaining flower quality during the post-harvest period since sugars were the main carbon source utilized for energy in the cut flower metabolism. The useful vase life of the cut blooms terminated when the flower heads started dropping which was followed by discoloration and fall of petals which represented the end of effective vase life of cut flowers (Nair et al., 2003). 213

10 Treatments of cut flowers with sucrose were found to be beneficial in delaying senescence processes and increase the longevity of the flowers (Yakimova et al., 1996). This beneficial effect of sugars on flower senescence was attributed to the supply of substrates for respiration, structural materials and osmoticum. AOA, an inhibitor of ACC synthase, has been vastly studied and proven to be effective in prolong the longevity of cut carnation and vase life of cut flower by inhibiting ethylene synthesis. Based on Yap et al. (2008) the AOA inhibits the activity of ACC synthase by complexing with the essential cofactor, pyridoxal phosphate. In this study, the results showed that the 50 ppm AOA was the best results among the other concentration. The discoloration of flowers treated with AOA was delayed for a significantly longer compared to that of the control (Zuliana et al., 2008). As in this study, the 50 ppm AOA showed the best results where the discoloration or the change of the colors occurred very slowly. Compound such as Aminooxyacetic Acid (AOA) effectively delayed senescence of climacteric flowers by inhibiting the action of 1-aminocyclopropane-1 carboxylate synthase (ACCS) (Zuliana et al., 2008). CONCLUSION It can be concluded that the flower longevity at 4% sucrose and 50 ppm AOA showed the best results. Both of this treated flowers exhibited the least senescence symptoms such as wilting, discoloration and hyponasty over a period of 4 days. These treated flowers showed the high water uptake, least senescence rate, least discoloration and longest vase life. In addition to that by this technique bougainvillea can retain longer beautification in the environment by its own bract longevity. ACKNOWLEDGMENT The author is thankful to his MS and PhD students to assist for this study in the field as well as in the laboratory. REFERENCES Chandran, S., C.L. Toh, R. Zuliana, Y.K. Yip, H. Nair and A.N. Boyce, Effects of sugars and aminooxyacetic acid on the longevity of pollinated Dendrobium (Heang beauty) flowers. J. Applied Hortic., 8: Cho, M.S., F.G. Celikel, L. Dodge and M.S. Reid, Sucrose Enhances the Postharvest Quality of Cut Flowers of Eustoma grandiflorum (Raf.) Shinn. In: Proceedings of the Seventh International Symposium on Postharvest Physiology of Ornamental Plants: Ft. Lauderdale, Florida, USA, November 1999, Nell, T.A. and D.G. Clark (Eds.). International Society for Horticultural Science, New York, USA., ISBN-13: , pp: Goh, C.J., A.H. Halevy, R. Engel and A.M. Kofranek, Ethylene evolution and sensitivity in cut orchid flowers. Scientia Horticulturae, 26: Harkema, H. and P.F. Struijlaart, Effect of amino-oxyacetic acid on coloration of the labellum and longevity of cut cymbidium flowers. Acta Horticulturae, 261: Hossain, A.B.M.S., A.N. Boyce and H.A.M. Majid, Vase life extension and chlorophyll fluorescence yield of bougainvillea flower as influenced by ethanol to attain maximum environmental beautification as ornamental components. Am. J. Environ. Sci., 4: Ketsa, S. and N. Narkbua, Effect of Aminooxyacetic acid and sucrose on vase life of cut roses. Acta Horticulturae, 543:

11 Nair, S.A., V. Singh and T.V.R.S. Sharma, Effect of chemical preservatives on enhancing vase-life of gerbera flowers. J. Trop. Agric., 41: Nichols, R., Senescence of the cut carnation flower: Respiration and sugar status. J. Hortic. Sci. Biotechnol., 48: Nickell, L.G., Plant Growth Regulators in Agriculture and Horticulture. Springer, New York, USA., Pages: 16. Roy, R.K., Bougainvillea: An excellent ornamental for ever green. Botanic Garden, National Botanical Research Institute, Rana Pratap Marg, Lucknow, , pp: 1-7. Van Doorn, W.G. and E.J. Woltering, Developments in the use of growth regulators for the maintenance of post-harvest quality in cut flowers and potted plants. Acta Horticulturae, 298: Woltering, E.J. and W.G. van Doorn, Role of ethylene in senescence of petals-morphological and taxonomical relationships. J. Exp. Bot., 39: Yakimova, E., V.K. Toteva, V. Alexieva, I. Sergiev and E. Karanov, Effect of chlorsulfuron (Glean-75) and sucrose on some postharvest physiological events in cut flowers. Bulgarian J. Plant Physiol., 22: Yang, S.F. and N.E. Hoffman, Ethylene biosynthesis and its regulation in higher plants. Ann. Rev. Plant Physiol., 35: Yap, Y.M., C.S. Loh and B.L. Ong, Regulation of flower development in Dendrobium crumenatum by changes in carbohydrate contents, water status and cell wall metabolism. Scientia Horticulturae, 119: Zuliana, R., A.N. Boyce, H. Nair and S. Chandran, Effects of aminooxyacetic acid and sugar on the longevity of pollinated Dendrobium pompadour. Asian J. Plant Sci., 7: