Einzelzellbiologie

Abstrakt

Evaluation of Agrobacterium-mediated transformation of two Nigerian cassava varieties (ManihotesculentaCrantz) TME 419 and

Nkaa, F. A

Evaluation of Agrobacterium -mediated transformation of two Nigerian cassava varieties ( Manihotesculenta Crantz) TME 419 and ‘Okwuoto’

Nkaa, FA, ^*1 Ene-Obong, EE, ² Afuape, SO, ³ Okwuonu, IC, ³ Kahya, SS ³ and Taylor, NJ ⁴

^*1 Department of Plant Science and Biotechnology, Michael Okpara University of Agriculture, Umudike, Abia State, Nigeria; ² Department of Biotechnology, University of Calabar, Cross River State, Nigeria.

Abstract:

For efficient transformation of cassava to increase crop yield, development of an effective protocol for genetic transformation is necessary. Ten Nigerian cassava varieties were tested in vitro for production of friable embryogenic callus (FEC) and transformation with Agrobacterium tumefaciens . All ten cassava genotypes tested produced organized embryogenic structures (OES) on Driver and Kuniyuki walnut (DKW) medium with 50 µM picloram between two and four weeks after culture using immature leaf lobes as explants. However, the percentage of OES formation was variety dependent. TMS 96/1632 produced the highest percentage of OES (66%), compared to TMS 60444 which served as a control sample and produced 80% OES. In contrast, only four varieties – two improved varieties (TMS 96/1632 and TME 419) and two local landraces (‘Okwuoto’ and ‘Nwugo’) – were able to produce friable embryogenic callus (FEC) compared to the production achieved by TMS 60444. In the somatic embryogenesis of cassava, the formation of FEC is very important as these are the target tissues for transgene insertion.

Keywords: Agrobacterium tumefaciens , fragile embryogenic callus, green fluorescent protein, transgenic.