Main Article Content
The traditional propagation technique of pear trees by grafting on quince, seedlings or clonal selection of Pyrus communis is not completely satisfactory. This is because of the lack of compatibility with some cultivars, heterogenesis of the pear seedlings and excess growth and also due to the sensitivity of the grafted plants to pear decline. For this the present study was conducted at the Tissue Culture Laboratory, Horticulture, Research Institute, Agricultural Research Center (ARC), Egypt during the period from December 2013 to March 2016 to investigate the effect of different media type Murashige and Skooge (MS), Gamborge (B5) and Woody plant media (WPM) at four salt concentrations (Full, ¾, ½ and ¼) of culture media on micropropagation of pear (Pyrus comumunis) cv. Le-Conte during the establishment stage. Shootlet proliferations were investigated at different concentrations of benzyl amino purine (BAP) and kinetin (Kin) at 0.25, 0.5 and 1.0 mg/l for each, during two successive subcultures. Finally, rooting capacity was studied by various concentrations of indole butyric acid (IBA) and indole acetic acid (IAA) at1.0, 2.0 and 3.0 mg/l on media containing activated charcoal. The culture explants were successfully disinfected by using Colorex 20% for 15 min with 100% survival and 100% free contamination. MS media at full strength was the best culture media that produced shootlet (1.33 shootlet/explant) and shootlet length 3.67 cm with 9.97 leaf/shootlets. Among the different concentrations, 1.0 mg/l BAP showed the highest shoot proliferation of 5.89 and 5.44 shoots per explant at the first and second subculture, respectively. The longest shoot (2.43 and 2.59 cm) was produced in the two subcultures by the treatment combination of 0.25 mg/l BAP. The highest numbers of roots were produced by 1.0 mg/l IAA were 8.0 roots/shootlet and the tallest length of roots were obtained for explants cultured on MS media containing IAA 3 mg/l and use mixture from NAA and 2,4-D 2:2 mg/l to get the highest value of callus formation 100%. Generally, it can be concluded from the obtained results that using Clorox 20% per 15 min at the disinfecting stage and using MS salt at full strength for the establishment stage, then using BAP at 1.0 mg / l to increase the number of shoots at the proliferation stage and using a mixture of NAA and 2,4-D 2:2 mg / l to obtain the highest value of callus formation. Moreover, using IAA at 1 mg / l to obtain the highest number of roots.
Nower AA, Ali EA, Rizkalla AA. Synthetic seeds of pear (Pyrus communis L.) rootstock storage In vitro. Aust J Basic Appl Sci. 2007;1(3):262–270.
Richard LB, Harvey AQ, Richard ECL, Robert MS. Pear. In: Jules J., James N.M. (eds.): Fruit Breeding,: Tree and Tropical Fruits. John Wiley and Sons, Inc., Hoboken. 1996;1.
Chevreau E, Skirvin RM, Abu-Qaoud H, Korban SS, Sullivan JG. Adventitious shoot regeneration from leaf tissue of three pear (Pyrus sp.) cultivars in vitro. Plant Cell Rep. 1989;7:688–691.
Predieri S, Fasolo FMF, Passey AJ, Ridout MS, James DJ. Regeneration from In vitro leaves of Conference and other pear cultivars (Pyrus communis): J. Hortic. Sci. 1989;64:553–559.
Abu-Qaoud H, Skirvin RM, Below FE. Influence of nitrogen form and NH4 +-N: NO3 –-N ratios on adventitious shoot formation from pear (Pyrus communis L.) leaf explants in vitro. Plant Cell Tissue Organ Cult. 1991;27:315–319.
Leblay E, Chevreau E, Raboin LM. Adventitious shoot regeneration from in vitro leaves of several pear cultivars (Pyrus communis L.): Plant Cell Tissue Organ Cult. 1991;25:99–105.
Lane WD, Iketani H, Hayashi T. Shoot regeneration from cultured leaves of Japanese pear (Pyrus pyrifolia): Plant Cell Tissue Organ Cult.1998;54:9–14.
Lee CH, Kim SB, Han DH, Kim CS, Noh YM, Ban SJ, Lee DW, Lee GP. Shoot organogenesis from leaf explants in Japanese pear (Pyrus pyrifolia): Acta Hort. 2004;653:215–218.
Murashige T, Skoog F. A revised medium for rapid growth and bioassays with tobacco tissue culture. Physiol. Plant. 1962;15:473- 497.
Gamborg OL, Mioller RA, Ojima K. Nutrient requirements of suspension cultures of soybean root cells. Exp Cell Res. 1968;50: 150–158.
McCown BH, Lloyd G. Woody Plant Medium (WPM)—A Mineral Nutrient Formulation for Microculture of Woody Plant Species. Hort Science. 1981;16:453-453.
Lane WD. Regeneration of pear plants from shoot meristem- tips. Plant Sci. Lett. 1979;16:337-342.
Singha S. In vitro propagation of Seckel pear. In: Proc Conf Nursery production of fruit plants through tissue culture: application and feasibility, 21-22 April Beltsville. 1980;59-63.
Bhojwani SS, Mullins K, Cohen D. In vitro propagation of Pyrus pyrifolia. Sci. Hortic. 1980;23:247-254.
Rehman HU. In vitro establishment and proliferation of Pyrus species International J. of Interdisciplinary Research. 2014;1:1-9.
Rehman HU, Gill MIS, Sidhu GS, Dhaliwal HS. Micropropagation of kainth (Pyrus pashia) - An important rootstock of pear in northern subtropical region of india J. of Experimental Biology and Agriculture Sciences. 2014;2:188-196.
Dobranszky J, Teixeira da Silva JA. Micropropagation of apple- A review. Biotechnol Adv. 2010;28:462-488.
Lane WD, McDougald JM. Shoot tissue culture of apple: Comparative response of five cultivars to cytokinin and auxin. Can J Plant Sci. 1982;62:689-694.
Modgil M, Sharma DR, Bhardwaj SV. Micropropagation of apple cv. ‘Tydeman’s’ ‘Early Worcester’. Sci Hortic. 1999;81: 179188.
Magyar-Tábori K, Dobránszki J, Jámbor-Benczúr. High in vitro shoot proliferation in the apple cultivar ‘Jonagold’ induced by benzyl adenine analogues. Acta Agron Hung. 2002;50:191-195.
Mahna N, Motallebi Azar A. In vitro micropropagation of apple (Malus x domestica Borkh.) cv. ‘Golden Delicious’. Comm Appl Biol Sci Ghent University. 2007;72:235-238.
Yeo D Y and Reed B M. Micropropagation of three Pyrus rootstocks. Hort Sci. 1995;30:620-23.
Bell RL, Reed BM. In vitro tissue culture of pear: Advances in techniques for micropropagation and germplasm conservation. Acta Hort. 2002;596:412-18.
Keresa S, Bosnjak AM, Baric M, Jercic IH, Sarcevic H, Bisko A. Efficient Axillary Shoot Proliferation and In vitro Rooting of Apple cv. ‘Topaz’ Not Bot Horti Agrobo . 2012;40(1):113-118.
Shibli RA, Ajlouni MM, Jaradat A, Aljanabi S, Shatnawi M. Micropropagation in wild pear (Pyrus syrica): Sci. Hortic. 1997; 68:237–242.
Baviera JA, Garcia JL, Ibarra M. Commercial in vitro micropropagation in pear cv. Conference. Acta Horticulturae. 1989;256:63-68.
Zhang CX, Li Q & Kong L. Induction, development and maturation of somatic embryos in Bunge's pine (Pinus bungeana Zucc. ex Endl.): Plant Cell Tissue and Organ Culture. 2007;91:273-280.
Victor MJ. Involvement of plant hormones and plant growth regulators on in vitro somatic embryogenesis. Plant Growth Regulation. 2005;47:91-110.
Becwar MR, Wann SR, Johnson MA, Werhagen SA, Feirer RP, Magmai R. Development and characterization of in vitro embryogenic systems in Conifers. In: Ahuja MR (ed) Somatic cell genetics of woody plants. Kluwer Academic Publishers, Dordrecht. 1988;1-18.
Razdan MK. Somatic embryogenesis. In: Razdan MK (ed), An introduction to plant tissue culture, Oxford & IBH Publi Co Pvt Ltd., New Delhi. 1993;87-102.
Evans DA. Sharp W, Flick C. Growth and behavior of cell cultures. In: Thorpe TA (ed) Plant Tissue Culture - Methods and Application in Agriculture, Academic Press, Orlando, Florida, USA. 1981;45-113.
Litz R, Schaffer B. Polyamines in adventitious and somatic embryogenesis in mango (Mangifera indica L.): Journal of Plant Physiology. 1987;128:251-258.
Lipaska H, Konradova H. Somatic embryogenesis in conifers: the role of carbohydrate metabolism. In vitro Cellular and Developmental Biology - Plant. 2004; 40:23-30.
Robichaud RL, Lesser VC, Merkle SA. Treatments affecting maturation and germination of American chestnut somatic embryos. Journal of Plant Physiology. 2004;161:957-969.