Full Length Research Paper

Genetic analysis of cry1Ab gene in segregating populations of rice

Ghaffar Kiani^1,2, Ghorban Ali Nematzadeh^1,2*, Behzad Ghareyazie³ and Majid Sattari⁴

¹Department of Agronomy and Plant Breeding, Sari University of Agricultural Sciences and Natural Resources, P.O. Box: 578, Iran.

²Rice and Citrus Research Institute, Sari-Iran.

³Agricultural Biotechnology Research Institute, Karaj-Iran.

⁴Rice Research Institute, Amol-Iran.

*Corresponding author. E-mail: ghanemat@gmail.com. Tel: 0098-911-1588678. Fax: 0098-151-3822715.

Accepted 12 May, 2009

Three transgenic Bt lines (Tarom Molaii, Neda and Nemat), all containing a synthetic cry1Ab gene were crossed with conventional rice varieties. The mode of resistance to striped stem borer (Chilo suppressalis) in these lines was investigated through field studies and PCR analysis of progenies in F₂ and BC₁ populations. The monogenic segregation of 3:1 and 1:1 were observed in segregating populations of F₂ and BC₁, respectively, either phenotypically under natural infestation of SSB as well as at molecular level by means of multiplexing PCR analysis using cry1Ab and RG100 primers. These results acquired from phenotypic and genotypic analyses of 1346 and 243 individual plants at field and laboratory conditions imply stable transmission of cry1Ab gene through sexual generations in indica/indica genetic backgrounds. Therefore, rapid development of new elite Bt rice cultivars with sufficient insect resistance and ideal agronomic properties can be achieved through combination of conventional breeding with marker assisted selection.

Key words: Rice, cry1Ab, segregation, insect resistance.