Biotechnology and Tissue culture
Mohammad Matani Borkheyli; Seied Mehdi Miri; Amrollah Nabigol
Abstract
Purpose: Micropropagation of GF677 rootstock, the most widely clonal rootstock used in peach orchards, is an important method for large-scale production of disease-free plants. In this research, effects of media, plant growth regulators and carbohydrates in order to optimize the efficient micropropagation ...
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Purpose: Micropropagation of GF677 rootstock, the most widely clonal rootstock used in peach orchards, is an important method for large-scale production of disease-free plants. In this research, effects of media, plant growth regulators and carbohydrates in order to optimize the efficient micropropagation protocol of GF677 rootstock has been investigated. Research method: In vitro shoots were multiplicated on MS, WPM and DKW media supplemented with 0, 0.5, 1, 2 mg L-1 BA. Proliferated shoots were rooted on MS, WPM and DKW media containing 0, 0.5, 1, 2 mg L-1 IBA. In another experiment, the effect of carbohydrate type was investigated. Findings: High shoot number and node number as well as shoot fresh weight were achieved with shoot tips when cultured on MS medium supplemented with 1 or 2 mg L-1 BA. The highest percentage of rooted shoots was obtained on MS or WPM media supplemented with 1 or 2 mg L-1 IBA. Maximum root number was regenerated on WPM medium containing 1 mg L-1 IBA. Sorbitol was found to be more effective carbon source on shoot multiplication than sucrose, while the highest average of root number and root length were observed in the medium containing sorbitol and sucrose medium, respectively. Survival rate during the acclimatization in the greenhouse was 67%. Limitations: Plant acclimatization needs to be studied for commercial production. Originality/Value: This protocol has proven useful for micropropagation of GF677 rootstock.

Biotechnology and Tissue culture
Mariem Lotfi; Chokri Bayoudh; Afifa Majdoub; Messaoud Mars
Abstract
Purpose: In Tunisia, pear cultivars are widely threatened by the attack of fire blight disease. Cultivation of tolerant cultivars is an effective control strategy for disease control. For this purpose, a reliable protocol was established for micropropagation of local Pyrus communis and Pyrus syriaca ...
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Purpose: In Tunisia, pear cultivars are widely threatened by the attack of fire blight disease. Cultivation of tolerant cultivars is an effective control strategy for disease control. For this purpose, a reliable protocol was established for micropropagation of local Pyrus communis and Pyrus syriaca L. and for large-scale production of high-quality plantlets. Research method: Using apical explants, different media and hormones were tested to establish a micropropagation procedure for local Tunisian Pyrus communis cultivars ‘Arbi’, ʻMaltiʼ, ʻMahdia 6ʼ and ʻMoknine 10ʼ and for Pyrus syriaca. Disinfection with 4% HgCl2 treatment for 20 minutes showed the highest percentage of plant survival. Successful initiation of the cultures was achieved on MS basal medium supplemented with 0.25 mg L-1 BA. Findings: During the proliferation stage, optimal shoot multiplication was obtained on MS medium with a half concentration of NH4NO3 and KNO3 supplemented with 0.1 mg L-1 IBA and 2 mg L-1 BA, but for maximum shoot length the BA concentration needed to be lowered to 1 mg L-1. A rooting rate of 100% and the highest root length and root number were attained on Cheng medium supplemented with 1.0 mg L-1 IBA. Pear vitroplants were successfully acclimatized on S2 substrate, composed by peat moss. Research limitations: Vitroplants acclimatization step needs to be well studied for the improvement of theacclimatized vitroplant survival rates by reducing the symptoms of crown rot. Originality/Value: This efficient optimized in vitro protocol will be successfully applied for large multiplication of high quality of Tunisian Pyrus vitroplants and cultivars.
Biotechnology and Tissue culture
Chadha Ayed; Chokri Bayoudh; Awatef Rhimi; Najla Mezghani; Faouzi Haouala; Bouthaina AL Mohandes Dridi
Abstract
Purpose: Tunisian garlic is widely threatened by the attack of several viruses genus. For this purpose, a reliable protocol was established for rapid in vitro propagation of local garlic (Allium sativum L.) cultivars for large-scale production of virus-free plants and high quality bulblets. ...
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Purpose: Tunisian garlic is widely threatened by the attack of several viruses genus. For this purpose, a reliable protocol was established for rapid in vitro propagation of local garlic (Allium sativum L.) cultivars for large-scale production of virus-free plants and high quality bulblets. Research method: Well disinfected shoot-tips of 1 mm were used as explants and cultivated on MS basal solid media enriched with various growth regulators: 6-Benzylaminopurine, α-Naphthaleneacetic acid, Kinetin, Indole-3-butyric acid and 2-isopentenyladenine for assessment of shoot formation, shoot proliferation and bulb formation. Findings: Among the different phytohormone concentrations and combinations, MS basal medium without any growth regulators (M0) was found optimal for shoot-tip initiation (96% explants development) and plantlets elongation (56.26 mm). For shoot proliferation, the M1 culture medium containing 1 mg L-1 BAP and 0.25 mg L-1 NAA was the best, giving a multiplication rate of 1.7 plantlets/explant. Shoots on M0 culture medium formed bulblets earlier. Multiple bulblets per explants were obtained on medium M22 containing 2 mg L-1 Kin and 0.1 mg L-1 NAA. Separated bulblets were transferred individually on bulbification media. Non-dividable bulblet was developed in various sizes. Research limitations: Bulblet acclimatization step needs to be well studied for high quality cloves production. Originality/value: This efficient optimized in vitro protocol will be successfully applied for large multiplication of virus-free garlic cultivars.