Pakistan Journal of Biological Sciences1028-88801812-5735Asian Network for Scientific Information10.3923/pjbs.2000.1285.1289Scirpophaga incertulas (Walker) and Rice Leaffolder, Cnaphalocrocis medinalis (Guenee) Populations to Bacillus thuringiensis δ-endotoxins]]>IntikhabS. KarimShahid RiazuddinS. 8200038Natural variability in susceptibility of field collected rice yellow stem borer (Scirpophaga incertulas) and rice leaffolder (Cnaphalocrocis medinalis) to Bacillus thuringiensis (Bt) δ-endotoxins was investigated to establish a geographic baseline for comparison of future population responses to the increased use of Bt based insect control products like Bt transgenic rice and commercial formulations. Populations of S. incertulas and C. medinalis were evaluated for their susceptibility to purified Bt Cry1Aa, Cry1Ab, Cry1Ac, Cry1C and Cry2A toxins. The range of LC50's among selected populations in response to variety of different Bt toxins were between 19-88 fold for S. incertulas and 2-20 fold for C. medinalis. The data provide a strong basis for monitoring changes in susceptibility of S. incertulas and C. medinalis populations to future use of Bt toxins in Bt rice program.]]>Altosaar, I., Z. Ali, R. Sardana, N. Mthukrishnan, X. Cheng, Q. Shu and H. Kaplan,19991999pp: 126Anwar, R., S. Karim and S. Riazuddin,1999Bacillus Thuringiensis transgenic rice plants against rice leaffolder, Cnaphalocrocis Medinalis (Lepidoptera: Pyralidae).]]>214721477Bradford, M.M.,197672248254Briese, D.T.,19811981pp: 511-545pp: 511-545Cohen, M.B., J.S. Bentur, R.M. Aguda, A.M. Romena and A.M. Dirie et al.,19991999pp: 25Ffrench-Constant, R.H. and R.T. Roush,19901990pp: 4-38pp: 4-38Georghiou, G.P.,19881988pp: 137-145pp: 137-145Gould, F.,199843701726Gould, F.,19944451461IRRI.,1997James, C. and A.F. Krattiger,19961996Karim, S. and S. Riazuddin,19992261276Karim, S. and S. Riazuddin,19991999Karim, S., K. Malik, U. Zafar and S. Riazuddin,1999Bacillus thuringiensis isolates against Scirpophaga incertulas and Cnaphalocrocis medinalis.]]>26167Karim, S., S. Riazuddin and D.H. Dean,1999Bacillus thuringiensis δ-endotoxins with midgut brush border membrane vesicles of Helicoverpa armigera.]]>2153162Karim, S. and S. Riazuddin,1997Bacillus thuringiensis-endotoxins: Molecular mechanism of action and pest management.]]>34135156Khan, E., S. Karim, R. Makhdoom and S. Riazuddin,1995Bacillus thuringiensis in Pakistanian environment.]]>38192195Khan, E., R. Makhdoom, S. Karim and S. Riazuddin,1995Tryporhyza incertulas and Cnaphalocrocis medinalis.]]>1995145-153145-153Karim, S., R.M. Aguda and S. Riazuddin,1994Bacillus thuringiensis isolates against the rice yellow stem borer Tryporhyza incertulas (Walker).]]>1994pp: 118120Kinsinger, R.A. and W.H. McGaughey,1979Bacillus thuringiensis.]]>72346349Laemmli, U.K.,1970227680685Le Ora Software,19871st Edn.,Mellon, M.G. and J. Rissler,1998Pages: 149Pages: 149Robertson, J.L, H.K. Preisler, S.S. Ng, L.A. Hickle and W.D. Gelernter,199588110Rossiter, M., W.G. Yendol and N.R. Dubois,1990Bacillus thuringiensis in gypsy moth (Lepidoptera: Lymantriidae): Genetic and environmental causes.]]>8322112218Sawicki, R.M.,19871987pp: 105-117pp: 105-117Siegfried, B.D., P.C.R.G. Marcon, J.F. Witkowski, R.J. Wright and G.W. Warren,1995Ostrinia nubilalis (Huebner)(Lepidoptera: Pyralidae), to Bacillus thuringiensis (Berliner).]]>12267273Stone, T.B. and S.R. Sims,1993Heliothis virescens and Helicoverpa zea (Lepidoptera: Noctuidae) to Bacillus thuringiensis.]]>86989994Tabashnik, B.E., 1994Bacillus thuringiensis. ]]>394779Tabashnik, B.E., N.L. Cushing, N. Finson and M.W. Johnson,1990Bacillus thuringiensis in diamondback moth (Lepidoptera: Plutellidae).]]>8316711676Van Frankenhuyzen, K., C.W. Nystom and B.E. Tabashnik,1995Bacillus thuringiensis among and within populations of the Spruce budworm (Lepidoptera: Tortricidae) in Ontario.]]>88 97105Whalon, M. E.,19921992pp: 119121