African Journal of

  • Abbreviation: Afr. J. Biotechnol.
  • Language: English
  • ISSN: 1684-5315
  • DOI: 10.5897/AJB
  • Start Year: 2002
  • Published Articles: 12463

Full Length Research Paper

Levels of control of Chilo partellus stem borer in segregating tropical Bt maize populations in Kenya

Mwimali G. Murenga1, Stephen M. Githiri2, Stephen N. Mugo3* and Florence M. Olubayo4        
1Kenya Agricultural Research Institute (KARI) – Biotechnology Centre, P.O. Box 57811 – 00200 Nairobi, Kenya. 2African Centre for Crop Improvement,  University of KwaZulu Private Bag X01 Scottsville 3209 KwaZulu-Natal, South Africa. 3International Maize and Wheat Improvement Center (CIMMYT), P.O. Box 1041 – 00621 Nairobi, Kenya. 4University of Nairobi, Plant Science and Crop Protection Department. P.O. Box 29053 - 00625 Nairobi, Kenya.
Email: [email protected]

  •  Accepted: 13 January 2011
  •  Published: 01 June 2011


In Kenya, stem borers destroy an estimated 400,000 metric tons, or 13.5%, of farmers' annual maize harvest costing about US$80 millions. Bacillus thuringiensis(Bt) maize controls stem borers without harming humans, livestock and the environment and was sown to 140m ha-1 globally in 2009. Two public Bt maize lines of cry1Ab::ubi gene (Event 216 and Event 223) were crossed with two non-Bt maize inbred lines, CML144 and CML159. The efficacy in the control of Chilo partellus stem borers in the parents, F1 and F2:3 successive generations were studied in a biosafety level 2 greenhouse. The Bt-gene effectively reduced stem borer damage with lower values for number of exit holes, tunneling length, proportion of stalk tunneled, number of larvae and number of pupae than the non Bt-maize and the check cultivars. The F1generations values for all damage parameters studied were comparable to those for the Bt-maize inbred lines as expected. The F2:3 generations showed a spread of damage parameters from resistant to susceptible. These results suggest that the Cry1A(b) genes in the study was inherited following the Mendelian segregation.


Key words: Bt maize, Chilo partellus, Bt δ-endotoxins, biosafety, greenhouse.


Bacillus thuringiensisBGHC, biosafety level 2 greenhouse complex; KARI, Kenya Agricultural Research Institute; KEPHIS, Kenya Plant Health Inspectorate Service; NBC, National Biosafety Committee.