IN VITRO REACTION AND EX VITRO ACCLIMATIZATION OF SOME AUTOCHTHONOUS VARIETIES OF SOLANUM TUBEROSUM L. (MURESAN, SUPER, CATY)
Agud Eliza, Vasile Laslo · SSRN Electronic Journal · 2013
The experiment is a continuation of our idea of conserving in vitro the potato varieties and populations ameliorated within the country on economical grounds and based on the fact that autochthonous elements are much better adapted to our climate conditions, more resistant to unfavorable conditions becoming more common (drought, attack of diseases and pests). Three varieties were taken in study: Muresan, Super and Caty ameliorated at The Potato Research Institute Brasov – Stupini, around the 1980s. The plant material consisted of apical meristem cultivated on Murashige-Skoog medium, 1962 improved with 825mg/l NH4NO3, with the following variants: Co=MS1/2; C1=MS+825mg/lNH4NO3+5g/l coal; C2=MS+825mg/lNH4NO3+0,1mg/lANA+1,0mg/l BA; C3=MS+825mg/lNH4NO3+0,1mg/lANA+2,0mg/lBA; C 4=MS+825mg/lNH4NO3+0,1mg/lANA+ 5g/lEP; C5=MS+825mg/lNH4NO3+0,1mg/lANA+80mg/lAdSO4 (Table 1). After three months from the incubation of the tissue on the mediums, observations were made concerning: the regeneration, multiplication and rooting percentage and observations concerning some parameters: the length of the plants, of the roots and layout changes of the varieties. The in vitro reaction of some varieties is dependent on the variety and on the composition of the culture mediums: the variety with the best reaction proved to be Muresan, but this reaction is different on the five mediums: on C3 it regenerates and multiply in vitro in a percentage of over 80%, rooting about 52%, generating a rich radicular system (10-12 roots with aerial roots on which there are placed tubers with a O of 0,5-0,6cm, proving to be the best medium. This variety has a reaction on all variants, but it is inferior to C3 medium. On C4 variant with 5g/l EP, Muresan variety reaches good values (we believe that due to the content of natural zeatin that can be found in the maize germ extract, and citokinin strongly involved in the regeneration of the vegetal tissue in vitro): the variety also presents a good reaction on the medium with cu AdSO4 (C5), but it is inferior to the other mediums. The other varieties have an inferior or a loose reaction depending on the medium: on Super and Caty they have the best reaction C3 and on C4 also (but inferior to Muresan variety). On the control medium Co the parameters are small and regeneration is situated between 10-8% and without rooting: on C1 in the presence of the vegetal coal and of NH4NO3 regeneration is much more better, but rooting does not take place in this case also (see Table 2). The method can ensure vegetal material for amelioration, can conserve in vitro the autochthonous populations and varieties, for the maintenance of a Romanian potato collection of interest. The potato varieties ameliorated at BrasovStupini have a different reaction, manifested in vitro in a longer time and inferior to the potato populations from Harghita county (experimented by us), but they are varieties which are resistant to unfavorable environmental conditions, with a certain genetic value for the Romanian ameliorators. For the success of the technique there shall be tested other medium formulas which may prove more effective.