Composição mineral do meio de cultura para crescimento in vitro de Cattleya walkeriana
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Data
2009-07-28
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Universidade Federal de Viçosa
Resumo
A família orquidácea possui cerca de 30.000 espécies espalhadas por quase todo o globo terrestre. Dentre as orquídeas, o grupo das catléias tem grande importância no mercado mundial de flores. Uma das principais formas de produção dessas plantas é o semeio assimbiótico in vitro. Muitos têm sido os meios de cultura utilizados para o semeio e crescimento de orquídeas; no entanto, esses meios parecem não suprir totalmente as exigências nutricionais das plantas. Há, portanto, grande interesse em se desenvolverem novos meios de cultura com composição nutricional que supra adequadamente, durante o período de cultivo, a demanda da cultura, promovendo produção de tecidos e resposta morfogênica deseja. O que constituiu o objetivo deste trabalho. Para ajustar as concentrações dos nutrientes do meio de cultura adequado para o crescimento de plântulas de catléia foram considerados os teores de referência em seus tecidos, a produção de matéria seca, o volume de meio de cultura por frasco e as taxas de recuperação dos nutrientes por essa cultura. Este meio foi denominado de meio Suprimento (S). Para a comparação desse meio de cultura com outros, protocormos de Cattleya walkeriana foram cultivados, durante 51, 94, 139 e 190 d, nos meios MS, B5, B&G (3 g L-1 do fertilizante B&G Orchidées®), Peters (3 g L-1 do fertilizante Peters® 10-30-20) e S, sendo testadas diferentes concentrações dos sais deste último (0,55; 0,73; 1,00 e 1,45 vez a concentração dos sais). O meio S, proposto neste trabalho, ofereceu a melhor condição de suprimento nutricional para a produção de plântulas de Cattleya walkeriana quando comparado com os demais meios. A concentração que proporcionou a máxima produção de plântulas completas foi de 1,125 vez a concentração original de sais do meio S. Os meios contendo maiores concentrações de N e menores de P levaram ao aumento na relação entre os teores de N e P (TN/TP) nos tecidos da cultura, a qual apresentou elevada correlação positiva com a relação entre a produção de matéria seca de calo e total. Alta relação TN/TP induziu a redução na produção de raízes. A relação entre a produção de raízes e folhas aumentou quando a concentração dos nutrientes no meio foi reduzida, seja pelo consumo da cultura ou pela redução na concentração dos sais no meio S.
The orchid family has about 30,000 species spread throughout most of the globe. Among the orchids, the group of Cattleya has great importance in the world flower market. One of the main forms of production of these plants is the in vitro assymbiotic seeding. Many have been the culture media used for sowing and growing orchids, however, these methods do not seem to fully supply the nutritional requirements of plants. There is, therefore, great interest in developing new culture media with nutritional composition that supplies properly the demand of the culture during the growing period promoting the production of tissues and the morphogenic response wanted. That was the aim of this work. To adjust the nutrient concentrations in the culture medium suitable for the growth of cattleya seedlings were considered the reference content in their tissues, the dry matter yield production, the volume of culture medium per vial and recovery rates of the nutrients by this culture. This medium was called the medium Supply (S). To compare this medium with others, Cattleya walkeriana protocorms were cultured for 51, 94, 139 and 190 d in MS medium, B5, B & G ( 3 g L-1 of fertilizer Orchidées B&G®), Peters (3 g L-1 of fertilizer Peters® 10-30-20) and S, and tested different concentrations of salts of the latter (0.55, 0.73, 1.00 and 1.45 as the concentration of salts). The medium S, proposed in this work, offered the optimum nutrient supply for the production of seedlings of Cattleya walkeriana when compared with other media. The concentration that provided maximum production of complete seedling was 1.125 time the original concentration of salts of the medium S. The media containing higher concentrations of N and lower P led to the rise in the levels of N and P (TN/TP) in tissue culture, which correlated positively with the ratio of dry matter yield of corn and total. High ratio TN/TP induced reduction in the production of roots. The relationship between the production of roots and leaves increased when the concentration of nutrients in the medium was reduced, because of the consumption of the culture or by reducing the concentration of salt in the medium S.
The orchid family has about 30,000 species spread throughout most of the globe. Among the orchids, the group of Cattleya has great importance in the world flower market. One of the main forms of production of these plants is the in vitro assymbiotic seeding. Many have been the culture media used for sowing and growing orchids, however, these methods do not seem to fully supply the nutritional requirements of plants. There is, therefore, great interest in developing new culture media with nutritional composition that supplies properly the demand of the culture during the growing period promoting the production of tissues and the morphogenic response wanted. That was the aim of this work. To adjust the nutrient concentrations in the culture medium suitable for the growth of cattleya seedlings were considered the reference content in their tissues, the dry matter yield production, the volume of culture medium per vial and recovery rates of the nutrients by this culture. This medium was called the medium Supply (S). To compare this medium with others, Cattleya walkeriana protocorms were cultured for 51, 94, 139 and 190 d in MS medium, B5, B & G ( 3 g L-1 of fertilizer Orchidées B&G®), Peters (3 g L-1 of fertilizer Peters® 10-30-20) and S, and tested different concentrations of salts of the latter (0.55, 0.73, 1.00 and 1.45 as the concentration of salts). The medium S, proposed in this work, offered the optimum nutrient supply for the production of seedlings of Cattleya walkeriana when compared with other media. The concentration that provided maximum production of complete seedling was 1.125 time the original concentration of salts of the medium S. The media containing higher concentrations of N and lower P led to the rise in the levels of N and P (TN/TP) in tissue culture, which correlated positively with the ratio of dry matter yield of corn and total. High ratio TN/TP induced reduction in the production of roots. The relationship between the production of roots and leaves increased when the concentration of nutrients in the medium was reduced, because of the consumption of the culture or by reducing the concentration of salt in the medium S.
Descrição
Palavras-chave
Orquídeas, Cultivo in vitro, Suprimento nutricional, Orchids, In vitro, Nutrient supply
Citação
SANTOS, André Ferreira. Mineral composition of the culture medium for in vitro growth of Cattleya walkeriana. 2009. 32 f. Dissertação (Mestrado em Fertilidade do solo e nutrição de plantas; Gênese, Morfologia e Classificação, Mineralogia, Química,) - Universidade Federal de Viçosa, Viçosa, 2009.