International Journal of Agriculture: Research and Review. Vol., 3 (2), 241-245, 2013 Available online at http://www.ecisi.com ISSN 2228-7973 ©2013 ECISI Journals MASS PROPAGATION OF Rosa hybrid CV.BLACK BACCARA BY PERIODICAL BIOREACTOR MINA BAYANATI 1 ,SEYED NAJMEDIN MORTAZAVI 2 1 - Graduate Student, Faculty Agriculture, University of Zanjan. 2- Assistant Professor, Faculty Agriculture, University of Zanjan. *Corresponding Author:MINA BAYANATI ABSTRACT: Roses have been one of the world’s most popular ornamental plants for a long time. Recently, in vitro flower induction in roses was demonstrated. To reduce the intensive labour requirement along with the production cost during plant propagation by tissue culture technique, there is an immense need of developing scale-up system and automation. Progress in tissue culture automation will depend upon the use of liquid culture in bioreactors. This system usually involves a wetting and drying cycle which occur periodically in a given period of time. Present investigation was carried out to determine the efficiency of in vitro propagation of Rosa hybrida cv. Black baccara with tow type periodical bioreactor. For mass propagation in bioreactors, 7-10 nodal segments were transferred into bioreactors containing VS liquid medium supplemented with 3% sucrose and 2 μM 6-Benzylaminopurine (BAP). The nutrition cycle was set at 10 min every 24h. The results showed that the semi- continuous system is more benefit than routine system (250ml jars) for shoot number, shoot length and fresh/dry weight. Comparative studies between two types periodical bioreactor indicated that there was not significant difference between the performances of two types of bioreactors. Plants produced in Bioreactor had better grown (3.39 and 0.57 g for fresh and dry weight, respectively) than plants which grown in 250 ml jars (0.56 and 0.02 g for fresh and dry weight, respectively). Also these kinds of bioreactor could be used for mass propagation with reduced cost, energy and handle work. Key words: In vitro, Liquid media, Periodical Bioreactor, Rose, Shoot multiplication. INTRIDUCTION Roses are the most economically important flowers in the world. There are than 20000 commercial cultivars, which are collectively based on only 8 of the 200 wild species in the genus rosa (Roberts and Smith, 1990). Traditionally, most ornamental roses are heterozygous and do not breed true to type, They are therefore propagated vegetative. Miniature roses are usually propagated by cutting but the roses are usually propagated by budding or bench-grafting onto rootstocks of species such as Rosa canina ‘ Inermis’ and Rosa multiflora ‘ Simplex’(Khosravi et al., 2007).Tissue culture on the other band in becoming increasingly popular as an alternative means of plant vegetative propagation. Automation of via organogenesis or somatic embryogenesis in a bioreactor has been advanced as a possible way of reducing costs (Paek et al., 2005).Bioreactors are usually described in a biochemical context as self- contained, sterile environments which capitalize on liquid nutrient or liquid/air inflow and outflow systems, designed for monitoring and control over conditions (agitation, aeration, dissolved oxygen, pH, etc.) (Ziv, 2000). Conventional plants are mainly in solid and semi-solid culture mediums that takes time and cost. In this regard, it is recommended to use moving fluid culture. Movements cause to get oxygen and nutrition to all tissues and make grow faster (Etinne and Berthouly, 2002).The same technology can be readily adapted for the growth of regenerable cells and tissues in liquid media in bioreactors, as demonstrated by the successful mass propagation of shoots in a 500 litre bioreactor by Akita et al (1994). They harvested64.6 kg of shoots of Stevia rebaudiana