An evaluation of Factors Determining Vitro Flowering of Embryo Derived Shoot of Oil Palm (Elaeis guineensis) Khairun Nizam 1,2,3 and Sompong Te-chato 3 1 Faculty of Agrotechnology, Islamic University of Riau, Pekanbaru 28111, Indonesia Email: khairun_nizam@yahoo.co.id 2 Faculty of Agriculture Brawijaya University, Malang, Indonesia Email: khairun_nizam@yahoo.co.id 3 Faculty of Natural Resources, Prince of Songkla University, Hat Yai 90110, Thailand Email: sompong.t@psu.ac.th/stechato@yahoo.com Abstract— Flowering is an important resulted from expandable of floral organs. In this particular study in vitro flowers were well developed from embryo derived shoot of oil palm (EDS) after 6 months on WPM medium containing 8 mg -l α-naphthalene acetic acid in combination with 12 mg -l Paclobutrazol with high concentration of sucrose (8%) and medium was subsequently subcultured every monthly prolonged to 6 months produced in vitro floral induction (10.2%). An early model due to precocious flowering on EDS of oil palm were occurred if there were long continued subculture for 6 months in the same culture medium whereas PGRs and Sucrose were beneficially contributed on regenerative organ regeneration. In the previous study histological examination has been made on the flowers produced by the inflorescence meristem revealed that these flowers were not true flowers. These flower-like structures were not found to have any reproductive structures and only contained bracts. This impacted that in vitro, under high sucrose and high concentration of NAA growth condition, the conversion of inflorescence meristem to a floral meristem is serious barier and being top priority concern among biotechnologist. The ability to control flowering will be feasible economically contributed to the oil palm industry and being recommended before exerted to the farmers. Keywords— paclobutrazol, plant growth regulators, sucrose, in vitro flowering, embryo derived shoots I. INTRODUCTION Blessed as miracle tropical plant, oil palm was well recognized with huge valuable and multipurpose in every economic sector in the developing country in Southeast Asia had been taken as strategically industrial project particularly. This aimed triggered to gain as much as principal sector income in every domain country of producer such as Indonesia, Malaysia and Thailand by demanded domestically and globally. In vitro oil palm propagation methods have been successfully improved [1][2] due to develop massive impact in currently oil palm research viewed. Realised that a big demand of global palm oil market flow continuously and promising for country producer, advanced research should be intensively prioritized as principle support in upstream sector and the reliable effectiveness methods is obtained by intended in vitro micropropagation approaches. A new innovation has been released on in vitro flowering study [3][4][5][6][7]. Moreover, that a large and increasing effort has been deployed to gain a better understanding of the underlying principles and control of the flowering and reproductive processes. So far, a huge flowering studies had been discussed but still not well synchronized on in vitro flowering of oil palm. A perfect created given a remarkable diversity exposed by oil palm flower shape and their great utility as morphological characters, it’s not brand new of issues some report have been a focus attention in recent years on oil palm studies in efforts of evolutionary and developmental biology especially. An-in dept the occurrence of vitro flowering of oil palm during in vitro propagation is probably controlled by vary complex factors such as flowering time and meristem identity genes [8][9][10]. There is no clear confirmed the influence on floral mechanism. It may be influenced by various factors affecting plant development [11], including hormones [12][13] and nutrient. In vitro flowering on oil palm is the understanding way that some report had been noted and it’s being valuable information for future biotechnology science in advanced. In this study, we summarized recent works was carried out on early vitro flowering that a new vitro flowers was coming out from embryo derived shoot during vitro propagation and could not be survived and functioned while replaced in ex vitro condition. Furthermore, a inflorescent study face a number of technical difficulties, but are vital in order to understand how flower structure determination can be explore and evaluate in coming future. 82