جوانه زنی جنین بالغ پکان (Carya illinoensis) در شرایط درون شیشه ای

نوع مقاله : مقالات پژوهشی

نویسندگان

1 دانشگاه فردوسی مشهد

2 سازمان تحقیقات آموزش و ترویج کشاورزی

چکیده

پکان یا گردوی گرمسیری (Carya illinoensis) از خانواده گردوئیان (Juglandaceae) و از محصولات خشکباری با ارزش می‌باشد. این گیاه از معدود میوه­های خشکبار است که در مناطق نیمه گرمسیری کشور قابل کشت است. مهم­ترین روش تکثیر پکان استفاده از پیوند است. بیشترین پایه تجارتی مورد استفاده برای پیوند پکان، نهال­های بذری خود پکان است. تولید کنندگان نهال معمولاً بذور حاصل از گرده افشانی آزاد را جهت تولید نهال بذری استفاده می­کنند. بذر برای پایه معمولاً از درختان قوی و یکنواخت گرفته می­شود. در این آزمایش که به صورت فاکتوریل و در قالب طرح بلوک‌های کامل تصادفی با سه تکرار انجام شد، اثر دو نوع محیط‌کشت، تعدادی از تنظیم کننده‌های رشد گیاهی و سرمادهی بذور بر روی جوانه‌ز‌نی جنین بالغ پکان در شرایط درون شیشه‎ای مورد مطالعه قرار گرفت. محیط‌کشت‎های مورد استفاده شامل محیط‌کشت موراشی و اسکوگ (MS) و محیط‌کشت درختان چوبی (WPM) بودند. تنظیم کننده‎های رشد گیاهی شامل ایندول بوتیریک اسید (صفر و یک میلی‌گرم در لیتر)، بنزیل آمینو پورین (صفر، یک و دو میلی‌گرم در لیتر) و جیبرلیک اسید (صفر و یک میلی‌گرم در لیتر) بودند. تیمار سرمادهی بذور به مدت 15 روز در دمای 5 درجه سانتی‌گراد اثر مثبتی بر روی درصد جوانه‌زنی و طول ساقه نداشت. نتایج نشان داد که بین محیط‌کشت‎ها اختلاف معنی‌داری از نظر میزان جوانه‌زنی در هر دو تیمار سرمادهی بذور و کشت بلافاصله بعد از برداشت (بدون سرمادهی) وجود داشت. بر این اساس بیشترین جوانه‌زنی در محیط‌کشت MS بود. همچنین بهترین رشد گیاهچه در محیط‌کشت MS با میزان یک میلی‌گرم در لیتر ایندول بوتیریک اسید، یک میلی‌گرم در لیتر اسید جیبرلیک و دو میلی‌گرم در لیتر بنزیل آمینو پورین به‌دست آمد.

کلیدواژه‌ها


عنوان مقاله [English]

In Vitro Mature Embryo Germination of Pecan (Carya illinoensis)

نویسندگان [English]

  • M. Ghazaeian 1
  • Gh.H. Davarynejad 1
  • K. Ghasemi Bezdi 2
  • S.H. Nemati 1
1 Ferdowsi University of Mashhad
2 Education and Extension Organization
چکیده [English]

Introduction: The walnut family (Juglandaceae) consists of approximately 60 species of deciduous trees is native of the American continents, Europe, and Asia. Pecan (Carya illinoensis) is belonged to the Juglandaceae family and is one of the most valuable nut products all over the world. Embryo culture techniques for plant breeding as well as basic studies in physiology and biochemistry are widely used. The low percentage of germination and the long propagation cycle and the need for stratification treatments from three to six months are the most important barriers to the development of high yielding cultivars through hybridization. Plant regeneration methods from embryo culture in vitro allows overcoming the barriers of hybridization, as well as obtaining higher and faster multiplication rate of plants of an elite genotype.
Materials and Methods: In this experiment, an adapted native genotype of pecan in Gorgan city, Golestan province, Iran was selected. The mature fruits were harvested after five months of pollination. They were immediately transferred to the laboratory. For cold pretreatment, nuts packed in a paper bag and stored in 4-5ºC for 15 days. The effect of two types of culture medium, growth regulators and seed pretreatment (15 days at 4-5 °C) on germination of mature embryos of pecan has been determined. Murashige and Skoog (MS) and Woody Plant Medium (WPM) and IBA (0 and 1 mgl-1), BAP (0, 1 and 2 mgl-1) and GA3 (0 and 1 mgl-1) media were used to embryo rescue evaluation. The data obtained were statistically analyzed in completely randomized block design (RCBD). Each treatment was replicated at least third, and each replicate consisted of two zygotic embryos. Means of germination period, percent of seed germination, root and shoot length and leaf number in different media and various PGRs combination were compared based on LSD at p ≤0.05.
Results and Discussion: The results showed, although cold pretreatment for 15 days had no effect on germination period, root length and number of leave but also, effect on germination percentage and shoot length. There are some different hypothesis about the effect of cold pretreatment on embryo germination between researchers. Some researchers believed that, there is low efficiency in embryo germination in lack of cold pretreatment and GA3. Cold pretreatment or GA3 reduce the ABA level and promote embryos germination. The others reported poor germination for somatic embryos when they treated with GA3 and cold pretreatments. Pearce et al. (1987) reported that GA3 and substrate of GA3 can be increased during the chilling process as ABA levels decrease. Furthermore, application of exogenous GA3 induces germination. Tang et al. (2000) reported that somatic embryos germination poorly happened in cold condition and addition of GA3 did not change the poor germination. Kaur et al. (2006) and Peyghamzadeh and Kazemitabar (2010), reported that the embryo germination in Juglans regia L. was higher when GA3 and cold pretreatments were simultaneously applied as compared to those when applied separately. In this experiment, media has no effect on embryo germination period but, could effect on other parameters. As the results showed, MS media showed the maximum percentage of germination, root and shoot length and number of leave in both condition (with and without cold pretreatment). In this experiment root length of germinated pecan embryo was higher in MS medium. Mapelli et al. (2001) reported that seed germination resulted in marked changes in the metabolism of free amino acids in walnut cotyledons. About 52% of the total free amino acids in one-month-old seedlings was present in the cotyledons and about 26% was in the taproot. The concentration of free amino acids in the taproot was similar to that in the embryonic axis, and greater than that in the cotyledons. T11 (1mg/l-1 IBA, 1mg/l-1BAP and 1mg/l-1 GA3) and T12 (1mg/l-1 IBA, 2mg/l-1BAP and 1mg/l-1 GA3) treatments were the highest in germination percentages in both treatment (with and without cold pretreatment). There was no significant differences between 1 mgl-1 and 2 mgl-1 of BAP.
Conclusion: Pecan as like walnut, is considered to be one of the most recalcitrant species in vitro. It is necessary to determine the optimal culture conditions to establish it for shortening time in seed propagation. This seedling could be applied as primary material for breeding programs, grafting and physiology study. The best growth of micro plant achieved in MS medium with 1 mgl-1IBA, 1 mgl-1GA3 and 2 mgl-1BAP.

کلیدواژه‌ها [English]

  • Micropropagation
  • Carya illinoensis
  • Proliferation
  • embryo
1- Ajamgard F., Rahemi M., and Vahdati K.2017. Detremining the pollinizer for Pecan cultivars. Journal of Nuts 8(1): 41-48.
2- Ajamgard F., Rahemi M., and Hassani D. 2013.Introduce pecan [Carya illinoinensis (Wagenh.) K. Koch] for Khuzestan province. Detection in Agronomical and Horticultural Plants 2(2): 129-142. (In Persian)
3- Deng M.D., and Cornu D. 1992. Maturation and germination of walnut somatic embryos. Plant Cell, Tissue and Organ Culture 28: 195-202.
4- Finkelstein R., Wendy R., Tohru A., and Camille S. 2008. Molecular aspects of seed dormancy. Annual Review of Plant Biology 59: 387-415.
5- Haroon A., and Aftab F. 2008. Adventitious regeneration of pecan using immature cotyledonary explant. Genomics, Proteomics, Metabolics: Recent trends in Biotechnology 352-354.
6- Hu H., Zhang Q., Jiang X., Huang J., Han K., Shen Y., Lv F., and Huang F. 2011. Efficient immature embryo germination in vitro of hickory (Carya cathayensis Sarg.). Propagation of Ornamental Plants 11(2): 96-101.
7- Heile-Sudholt C., Huetteman C.A., Preece J.E., Van Sambeek J.W., and Gaffney G.R. 1986. In vitro embryonic axis and seedling shoot tip culture of Juglans nigra L. Plant cell, Tissue and Organ Culture 6: 189-197.
8- Jafari Mofidabadi A. 2014. Application of Embryo Rescue Technique in Juglans regia L. x J. nigra L. Hybridization. Journal of Medicinal Plants and By-products 2: 211-214.
9- Kaur R., Sharma N., Kumar K., Sharma D.R. and Sharma S.D. 2006. In vitro germination of walnut (Juglans regia L.) embryos. Scientia Horticulturae 109: 385-388.
10- Lee B.C., Shim S.Y., and Lee S.K. 1988. Mass propagation of somatic embryos in Juglans regia L. (English walnut). Research Report of the Institute of Forest Genetics, Korea 24: 99–106.
11- Mapelli S., Bram Billa I., and Bertani A. 2001. Free amino acids in walnut kernels and young seedlings. Tree Physiology 21: 1299-1302.
12- McCown B.H., and Lloyd G. 1981. Woody Plant medium (WPM)-a mineral nutrient formulation for microculture of woody plant species. Hortscience 16: 453.
13- Murashige T., and Skoog F. 1962. A revised medium for rapid growth and bioassay with tobacco tissue cultures. Physiologia Plantarum 15: 473-497.
14- Obeidy A., and Smith M.A.L. 1993. Organogenesis and somatic embryogenesis from mature pecan embryonic axes. Horticulture Science 28: 213-215.
15- Payghamzadeh K., Kazemitabar S.K., and Amiri A. 2011. Effects of Two Type of Medium Cultures, Gibberellic Acid and Some Physical Factors on Persian Walnut (Juglans regia L.) Embryos Germination. Journal of Horticulture Science 25 (1): 45-54.
16- Payghamzadeh K., and Kazemitabar S.K. 2010. In vitro germination of Pecan (Carya illinoinensis) embryo. Biharean Biologist 4(1): 37-43.
17- Rajasekaran K., Vine J., and Mullins M.G. 1982. Dormancy in somatic embryos and seeds of Vitis: changes in endogenous abscisic acid during embryogeny and germination. Planta 154: 139-144.
18- Renukdas N.N., Manoharan M., and Garner J.O. 2010.In vitro propagation of pecan [Carya illinoensis (Wangenh.) K. Koch]. Plant Biotechnology 27: 211-215.
19- Renukdas N.N., Manoharan M., and Garner J.O. 2008. In vitro plant regeneration of pecan [Carya illinoensis (Wangenh) K. Koch]. In Vitro Cell & Developmental Biology-Plant 44: 342-363.
20- Saadata Y.A., and Hennerty M.J. 2002. Factors affecting the shoot multiplication of Persian walnut (Juglans regia L.). Scientia Horticulturae 95: 251–260.
21- Sanchez-Zamora M.A., Diego Frutos Tomas J.C.T., and Garcia-Lopez R. 2006. Embryo germination and proliferation in vitro of Juglans regia L. Scientia Horticulturae 108(3): 317-321.
22- Sharma D.R., Kaur R., and Kumar K.1996. Embryo rescue in plants, a review. Euphytica 89: 325-337.
23- Sun T.P., and Frank G. 2004. Molecular mechanism of gibberellin signaling in plants. Annual Review of Plant Biology 55: 197-223.
24- Tang H., Zhenglong R., and Gabi K. 2000. Improvement of English walnut somatic embryo germination and conversion by desiccation treatments and plantlet development by lower medium salt. In Vitro Cellular & Developmental Biology-Plant 36: 47-50.
25- Thompson, Tommy E. and Conner, Patrick J.2012. "Chapter 20: Pecan". Publications from USDA-ARS / UNL Faculty. 1322p.
26- Toosi S., Dilmaghani K., and Hikmatshoar H. 2010. Proliferation of Juglans regia L. by in vitro embryo culture. Middle-East Journal of Scientific Research 6 (1): 1-7.
27- Tulecke W., and McGranahan G.H. 1985. Somatic embryogenesis and plant regeneration from cotyledons of walnut, Juglans regia L. Plant Science 40: 57–63.