Edoh N.L., Okwuonu I., Onyeka J. and C.N. Egesi
Biotechnology Program National Root Crops Research Institute (NRCRI), Umudike, Nigeria
Considerable efforts have been directed to optimize the conditions for in-vitro stages of micropropagation of cassava, but the process of acclimatization of micropropagated plants to the soil environment has not fully been achieved. Five hundred and fifty four cultures of genetically modified (GM) cassava were received from University of Zurich (ETH) for ex-vitro adaptation and confined field trial in National Root Crops Research Institute, Umudike, Nigeria. The effect of genotype on ex-vitro adaptation of GM cassava was evaluated by considering the survival rate, growth rate and vigor and analysed statistically using ANOVA. There was no significant difference observed between the survival rates of TMS 6044, TME 3, TME 7 and TME 14 in the humidity chamber (F= 0.23 at P>0.05). Their growth rate and vigor equally showed no significant difference (F=3.71, 4 at P>0.05) in the screen house as they performed same. Effect of transgene showed no adverse effect on survival rate, growth rate and vigor (F=0.04, 2.59 and 3.50 at P>0.05). TMS 60444 was transformed with different constructs and recovered events were compared with nontransgenic and transformed cassava without transgene (p1300). The individual construct had no adverse effect on the adaptation of the GM cassava as no significant difference was observed in their survival rate (F=0.21 at P>0.05), growth rate (F=1.5 at P>0.05) and vigor. The transgenic event performed favourably in comparison with the non-transgenic. In this study, the transgene had no adverse effect on ex-vitro adaptation of genetically modified cassava genotypes for CMD resistance.
Keywords: Ex-vitro, acclimatization, transgenic, cassava