Biotechnology1682-296x1682-2978Asian Network for Scientific Information10.3923/biotech.2011.267.273KeyeoF. Ai`shahO. NoorAmirH. G.32011103The aim of this study was to observe the influence of diazotroph inoculation on growth of paddy plants under greenhouse conditions. Diazotroph are the most studied and well known Plant Growth-Promoting Rhizobacteria (PGPR) that are able to promote plant growth via Biological Nitrogen Fixation (BNF) and phytohormone production. A total of four diazotrophic bacteria inocula were used for the experiment which include Azospirillum brasilense (Sp7), Herbaspirillum seropedicae (Z78), Enterobacter sp. (L2) and Gluconacetobacter sp. (L15). All four strains were able to fix nitrogen with the same ability but produces phytohormone indole-3-acetic acid (IAA) in different concentration. The inoculation effects were tested on paddy plants (Oryza sativa) variety MR220. The rice seedlings were planted in non-sterilized soil and grown under aerobic conditions. Growth of the host plants was measured on parameters such as plants dry weight, plants height, root elongation and total leaf chlorophyll and protein content. Results showed that following inoculation, overall plant growth observation for plants inoculated with L2 and Control positive (+100% N fertilizer) showed better plant growth compared to plants inoculated with L15, Sp7, Z78 and Control negative (+Sp7K). Plants inoculated with Sp7 and Z78 both showed inferior growth compared to Control negative due to excess amount IAA supplied by the inoculants that suppresses the plant growth. Results also showed promising effect of L2 inoculants, to promote rice growth through optimal phtyhormone (IAA) production activity plus the added benefit through successful fixed nitrogen intake by the plant that was provided by L2 via BNF.]]>Anthony, O.A., J.A. Daniel, J.B. Carols and J.S. Jan,20092009pp: 287-300pp: 287-300Asghar, H., Z. Zahir, M. Arshad and A. Khaliq,2002in vitro production of auxins by rhizobacteria and their growth promoting activities in Brassica juncea L.]]>35231237Ashrafuzzaman, M., F.A. Hossen, M.R. Ismail, M.A. Hoque, M.Z. Islam, S.M. Shahidullah and S. Meon,2009812471252Azlin, C.O., H.G. Amir, L.K. Chan and I. Zamzuri,2009Elaeis guineensis Jacq.).]]>207177Baca, B.E. and C. Elmerich,20072007pp: 113-143pp: 113-143Baldani, J.I., V.M. Reis, V.L.D. Baldani and J. Dobereiner,200229417423Baldani, I.J. and L.V. Baldani,200577549579Barazani, O. and J. Friedman,19992523972406De Bashan, L.E., H. Antoun and Y. Bashan,2008Azospirillum sp. in promoting browth of Chlorella vulgaris.]]>44938947Boddey, R.M.,199514263279Chasan, R.,19935597599Yaqub Chaudhry, N.,20052 on the seedlings of Pisum sativum L.]]>816431648Ryu, C.M., C.H. Hu, R.D. Locy and J.W. Kloepper,2005Arabidopsis thaliana.]]>268285292Gough, C., J. Vasse, C. Galera, G. Webster, E. Cocking and J. Denarie,1997Arabidopsis thaliana as a model plant.]]>194123130Gray, E.J. and D.L. Smith,200537395412Davies, P.J.,20102010pp: 1-15pp: 1-15De Weger, L.A., A.J. van der Bij, L.C. Dekkers, M. Simons, C.A. Wijffelman and B.J.J. Lugtenberg,1995Pseudomonads.]]>17221228Fassler, E., M.W. Evangelou, B.H. Robinson and R. Schulin,201080901907Frankenberger, Jr. W.T. and M. Arshad,1995Pages: 503Pages: 503Gaspar, T., O. Faivre-Rampant, C. Kevers, J. Dommes and J.F. Hausman,2002pp: 383-403pp: 383-403Hoque, M.M., K. Inubushi, S. Miura, K. Kobayashi, K.H. Yong, M. Okada and S. Yabashi,200134453459Jacoud, C., D. Job, P. Wadoux and R. Bally,1999Azospirillum lipoferum CRT1 during maize seed germination.]]>45339342Kennedy, I.R. and Y.T. Tchan,199214193118Khalid, A., M. Arshad and Z.A. Zahir,200496473480Kloepper, J.W., F.M. Scher, M. Laliberte and B. Tipping,19861986pp: 155-164pp: 155-164Lucy, M., E. Reed and B.R. Glick,200486125Lowry, O.H., N.J. Rosebrough, A.L. Farr and R.J. Randall,1951193265275Malhotra, M. and S. Srivastava,2008Azospirillum brasilense strain MS and its implications on indole-3-acetic acid biosynthesis and plant growth promotion.]]>93425433Malhotra, M. and S. Srivastava,2006Azospirillum brasilense SM with indole acetamide pathway for iaa over-expression.]]>5210781084Malhotra, M. and S. Srivastava,2008Azospirillum brasilense strains: Molecular and functional analysis of ipdc in strain SM.]]>1013651373Malhotra, M. and S. Srivastava,2009Azospirillum brasilense SM and its ability to modulate plant growth.]]>457380Martinez-Viveros, O., M.A. Jorquera, D.E. Crowley, G. Gajardo and M.L. Mora,201010293319Meunchang, S., S. Panichsakpatana, S. Ando and T. Yokoyama,2004Azospirillum isolates in Thailand.]]>50413421Mia, M.A.B. and Z.H. Shamsuddin,20106235242Neufeld, H.S., A.H. Chappelka, G.L. Somers, K.O. Burkey, A.W. Davison and P.L. Finkelstein,200687281286Nguyen, H.T., R. Deaker, I.R. Kennedy and R.J. Roughley,200335261265Ai'shah, O.N. and H.G. Amir,2005Herbaspirillum sp. and Locally Isolated Diazotrophic Rhizobacteria on Growth of Aerobic Rice.]]>2005pp: 379-381pp: 379-381Ai'shah, O.N., H.G. Amir, C.L. Keng and A.R. Othman,20102 fixation capacity of oil palm seedlings (Elaeis guineensis Jacq.).]]>42139149Park, M., C. Kim, J. Yang, H. Lee, W. Shin, S. Kim and T. Sa,2005160127133Patten, C.L. and B.R. Glick,199642207220Raj, S.N., G. Chaluvaraju, K.N. Amruthesh, H.S. Shetty, M.S. Reddy and J.W. Kloepper,2003Pennisetum glaucum) by rhizobacteria.]]>87380384Sachs, T.,199320531533Sofi, P. and S. Wani,20076203213Somasegaran, P. and H.J. Hoben,1985pp: 1-46pp: 1-46Verma, J.P., J. Yadav, K.N. Tiwari, Lavakush and V. Singh,20105954983Vessey, J.K.,2003255571586Watanabe, I., T. Yoneyama, B. Padre and J.K. Ladha,1987Oryza sativa L.) varieties.]]>33407415Woyessa, D. and F. Assefa,2011Eragrostis tef Zucc. Trotter) under greenhouse condition.]]>6343355Yasmin, F., R. Othman, K. Sijam and M.S. Saad,20077421424Yasmin, F., R. Othman, K. Sijam and M.S. Saad,20093815821Zahir, Z.A., M. Arshad and W.T. Frankenberger Jr.,20048197168Zhu, Z.,1989pp: 151-164pp: 151-164Zimmer, W. and H. Bothe,1989Azospirillum and Wheat.]]>1989pp: 137-146pp: 137-146Patten, C.L. and B.R. Glick,2002Pseudomonas putida indoleacetic acid in development of the host plant root system.]]>6837953801Van Loon, L.C.,2007119243254Kennedy, I.R., A.T.M.A. Choudhury and M.L. Kecskes,20043612291244