Use of sodium hipochlorite in sterilization of culture medium for multiplication of Eucalyptus pellita L.

Ultimamente, vem-se observando grande interesse na \ue1rea de pesquisa em cultura de tecidos vegetais, em se descobrir novas op\ue7\uf5es que resultem na redu\ue7\ue3o dos custos da micropropaga\ue7\ue3o das plantas em laborat\uf3rios comerciais, de modo a torn\ue1-la mais vi\ue1vel economicamente. Uma op\ue7\ue3o potencialmente promissora para a redu\ue7\ue3o de custos, mas que n\ue3o tem recebido a devida aten\ue7\ue3o, \ue9 a perspectiva de se substituir a t\ue9cnica de autoclavagem por outra mais econ\uf4mica. Com esse objetivo, foram realizados dois testes utilizando um novo protocolo de preparo do meio, que consistiu na esteriliza\ue7\ue3o qu\uedmica de todos os utens\uedlios utilizados no preparo e acondicionamento do meio de cultura, associado \ue0 adi\ue7\ue3o do esterilizante ao meio em diferentes concentra\ue7\uf5es. O primeiro teste teve como objetivo observar a influ\ueancia de diferentes concentra\ue7\uf5es de NaClO adicionado ao meio de cultura sobre a esteriliza\ue7\ue3o deste. O segundo objetivou verificar a rea\ue7\ue3o dos tecidos de Eucalyptus pellita a diferentes concentra\ue7\uf5es de NaClO adicionado ao meio de cultura. A adi\ue7\ue3o, ao meio de cultura, de concentra\ue7\uf5es iguais ou superiores a 0,0005% no primeiro teste e de 0,005% no segundo, permitiu completa esteriliza\ue7\ue3o do meio, n\ue3o se tendo observado qualquer dano aos tecidos do Eucalyptus pellita , quando cultivado em meio de cultura com at\ue9 a concentra\ue7\ue3o m\ue1xima testada, de 0,009% de NaClO. Os resultados obtidos mostraram a viabilidade de dispensar o uso da autoclave para a esteriliza\ue7\ue3o de meios de cultura para esta esp\ue9cie.Lately it has been observed a great interest in the research area of plant tissue culture in discovering new alternatives leading to cost reduction of the plants produced in commercial laboratories, in order to turn this alternative of plant propagation more economical. A potentially promising alternative for this reduction of costs, but which has not been receiving the due attention, is the possibility of substituting the autoclaving technique to a more economical one. With this purpose, two tests were carried out, using a new protocol of medium preparation, which consisted of the chemical sterilization of all the utensils used in the preparation and packaging of the culture medium as well, associated to the addition of the sterilizing agent to the medium, in different concentrations. The objective of the first test was to observe the influence of different concentrations of NaClO added to the culture medium, on its sterilization. The second test aimed at verifying the reaction of the Eucalyptus pellita tissues to different concentrations of NaClO in the culture medium. The addition of NaClO to the culture medium, equal or higher than 0.0005% in the fist test and of 0.005% in the second one, allowed complete sterilization of the medium, without observing any damage to the Eucalyptus pellita tissues, even when they were grown on culture medium containing up to 0.009%, the maximum concentration tried. The results showed the viability of eliminating the autoclave for the sterilization of culture media