نوع مقاله : مقاله پژوهشی
نویسندگان
1 استادیار، پژوهشکده خرما ومیوه‌های گرمسیری، موسسه تحقیقات علوم باغبانی، سازمان تحقیقات، آموزش وترویج کشاورزی، اهواز، ایران.
2 استادیار، بخش تحقیقات علوم زراعی و باغی، مرکز تحقیقات و آموزش کشاورزی و منابع طبیعی بلوچستان، سازمان تحقیقات، آموزش و ترویج کشاورزی، ایرانشهر، ایران.
3 کارشناس تحقیقاتی، پژوهشکده خرما و میوه‌های گرمسیری، موسسه تحقیقات علوم باغبانی، سازمان تحقیقات، آموزش و ترویج کشاورزی، اهواز، ایران.
چکیده
کلیدواژه‌ها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
The aim of this study was to determine the optimal conditions for in vitro culture initiation of pineapple cv. MD2 using tissue culture technique, in three different experiments. In the first experiment, the effect of sterilization treatment on contamination, mortality and development rate of explants was investigated. In the second experiment, the buds were divided into five groups based on their position on the pineapple stem to determine the highest rate of bud regeneration. In the third experiment, the effect of different concentrations of benzyl adenine (BA) (0, 0.1, 0.5 and 1 mgl-1) was studied alone or in combination with 0.01 mgl-1 of naphthalene acetic acid (NAA) concentrations on regeneration of buds. The results showed that sodium hypochlorite (2.5%) in 20 minutes was the most effective for sterilizing pineapple buds. All concentrations of BA promoted bud regeneration but the 3 mgl-1 was the optimum. Apical buds and the third section axillary buds had the highest regeneration rate at 93% and 92%, respectively.
Keywords: Pineapple, benzyl adenine, apical bud, tissue culture, sodium hypochlorite.
Introduction
Pineapple [Ananas comosus (L.) Merr.] is one of the most economically important tropical fruit that belongs to Bromeliaceae. Pineapple plants can be propagated using vegetative materials of slips, suckers, stem sections or crowns. However, in all these three cases plant material is often limited, thus in vitro culture is a commercial alternative approach. In vitro micropropagation of pineapple plantlets has many advantages over conventional methods of vegetative propagation. Tissue culture enhances rapid propagation of suckers to supplement conventional methods to produce pineapples to meet both local and international market demands (Shamim et al., 2016). However, tissue culture initiation, the most critical step towards rapid in vitro propagation, is challenged by microbial contamination, exogenous growth hormone requirements and bud type for growth (Vujovic et al., 2012). Therefore, the aim of this study was to determine optimal sterilization protocols and BA concentration to initiate pineapple in vitro culture using apical and axillary buds as sources of explants.
Materials and Methods
In this study the buds of suckers of pineapple cv. MD2 was used for in vitro culture in three different experiments. In the first experiment, explants were sterilized with sodium hypochlorite and ethanol at different concentrations, alone or in combination, and durations (2.5% sodium hypochlorite for 5, 10, 15 minutes, 70% ethanol for 3, 5, 7 minutes, 1% sodium hypochlorite for 10 minutes + 70% ethanol for 3 minutes and 2.5% sodium hypochlorite for 15 minutes + 70% ethanol for 1 minute), followed by three rinsing with sterilized distilled water under aseptic conditions. The explants were placed on solidified Murashige and Skoog (MS) based medium supplemented with 0.5 mgl-1 of benzyl adenine (BA) combined with 0.1 mgl-1 of naphthalene acetic acid (NAA). In the second experiment, buds were grouped based on their position on the pineapple stem (apical, 1st section, 2nd section, 3rd section, and 4th section) to determine the highest rate of bud regeneration. Following sterilization, different buds were transferred to MS medium containing 1 mgl-1 BA+ 0.1 mgl-1 NAA at pH = 5.8. In the third experiment, the effect of different concentrations of BA (0, 0.1, 0.5 and 1 mgl-1) was studied alone or in combination with 0.01 mgl-1 NAA concentrations on regeneration of buds.
Results and Discussion
The results showed that sodium hypochlorite (2.5%) in 20 minutes was the most effective in sterilizing pineapple buds. The effectiveness of sodium hypochlorite (2.5%) enhanced with increasing exposure time. The highest explant regeneration rate was observed in the disinfection treatment with 2.5% sodium hypochlorite for 20 minutes (84.49%) followed by 2.5% sodium hypochlorite treatment for 15 minutes + 70% ethanol for 1 minute (75.39%). Ethanol alone could not successfully disinfect pineapple buds. There was high level of harmful microbial contamination of plant tissues associated 70% ethanol treatment, hence the cultures deteriorated.
The apical bud followed by the third section buds were the first to show growth and had the highest rate of regeneration (95% after two weeks). The third section buds recorded (90%) regeneration rate within 1-3 weeks.
All concentrations of BA promoted bud regeneration. The highest regeneration rate was observed in the culture medium containing BA at concentration level of 3 mgl-1 and 0.1 mgl-1 NAA with an average of 75.75%. The lowest regeneration rate in the MS culture medium without growth regulators with an average of 42%. These results are in agreement with findings of Zuraida et al. (2011) and Usman et al, (2013).
References
Shamim, M., Kumar, M., Ranjan, T., Kumar, R. R., Pal, A. -K., Kumar, V., Jha, V. B. and Kumar, P. 2016. Importance of micropropagation in pineapple fordisease free plantlets and rapid multiplication. Journal of Pharmacognosy and Phytochemistry, 5(4), pp. 359-362.
Usman, I. S. 2013. Development of an efficient protocol for micro propagation of pineapple. African Journal of Agricultural Research, 8(18), pp.2053-2056. DOI: 10.5897/AJAR12.1763
Vujovic, T., Ruzic, D. J. and Cerovic, R. 2012. In vitro shoot multiplication as influenced by repeated subculturing of shoots of contemporary fruit rootstocks. Horticultural Science, 39, pp.101-107. DOI: 10.17221/208/2011-HORTSCI
Zurida, A. R., Shahanadz, A. H. N., Harteeni, Roowi, S., Che Radziah, C. M. Z. and Sreeramanan, S. 2011. A novel approach for rapid micropropagation of maspine pineapple shoots using liquid shake culture system. African Journal of Biotechnology, 10, pp.3859-3866.
کلیدواژه‌ها [English]
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