Paclobutrazol no crescimento e desenvolvimento in vitro e na aclimatização de Sophronitis cernua (Lindl.) Lindl. e Brassavola flagellaris Barb. Rodr. (Orchidaceae)
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Data
2012-04-19
Autores
Ichinose, Juliana Garcia dos Santos [UNESP]
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Universidade Estadual Paulista (Unesp)
Resumo
Sophronitis cernua e Brassavola flagellaris são orquídeas epífitas, nativas do Brasil. O cultivo in vitro é uma técnica que permite produzir grande número de indivíduos, entretanto ocorrem muitas perdas durante o período de aclimatização (ex vitro). Em razão disto, este trabalho teve como objetivo estudar o efeito da suplementação do meio de cultura Murashige e Skoog com paclobutrazol, no crescimento e desenvolvimento de plântulas de Sophronitis cernua e Brassavola flagellaris (in vitro), visando aumentar a taxa de sobrevivência das plântulas ex vitro. O delineamento experimental utilizado foi inteiramente casualisado. Foram quatro tratamentos (três concentrações de paclobutrazol: 0,5; 1,0 e 1,5 mg i.a. L-1 e controle) e 10 repetições com 12 plântulas. Após cultivo em meio sem suplementação, as plântulas foram inoculadas nos tratamentos, onde permaneceram por mais 90 dias. Após este período, cinco repetições foram separadas para as análises destrutivas e as outras cinco foram transplantadas para bandejas contendo fibra de coco (S. cernua) e mistura de fibra de coco e esfagno (B. flagellaris). Verificou-se que as diferentes concentrações de paclobutrazol promoveram alterações nas características morfológicas das plântulas das duas espécies. Para S. cernua foi verificada redução do número de folhas, área foliar, massa seca e comprimento da parte aérea; aumento no diâmetro e massa seca de raízes e redução na taxa de sobrevivência das plântulas. Para B. flagellaris houve incrementos no acúmulo de massa seca de todas as partes (exceto na maior concentração para parte aérea), no número de folhas, na área foliar (0,5 mgL-1), no diâmetro no comprimento de raízes e no número de raízes; redução no número de brotos e comprimento da parte aérea e maiores taxas de sobrevivência da plântulas
Sophronitis cernua and Brassavola flagellaris are orchids epiphytes, native of Brazil. The in vitro propagation is a technique that allows to produce large numbers of plants, however many losses occur during the period of acclimatization (ex vitro). For this reason, this work aimed to study the effect of supplementation of the Murashige and Skoog medium with paclobutrazol on growth and development of plants of Sophronitis cernua and Brassavola flagellaris (in vitro) to increase the survival rate of seedlings ex vitro. The experimental design was completely randomized. There were four treatments (three concentrations of paclobutrazol: 0.5, 1.0 and 1.5 mg ai L-1 and control) and 10 repetitions with 12 plants. After cultivation in medium without supplementation, the seedlings were inoculated on treatments, where they remained for another 90 days. After this period, five replicates were separated for destructive analysis and the other five were transplanted into trays containing coir (S. cernua) and a mixture of coconut fiber and sphagnum moss (B. flagellaris). It was found that paclobutrazol induced changes in the morphological characteristics of both species. To S. cernua: reducing the number of leaves, leaf area, dry weight and shoot length and increase in diameter and dry mass of roots. Reduction in the rate of seedling survival. To B. flagellaris: increases in dry mass of all parties, except at the highest concentration (aerial part), the number of leaves, leaf area (0.5 mgL-1), diameter, length of roots and more roots. Reduction in the number of shoots and shoot length. Highest survival rates of seedlings
Sophronitis cernua and Brassavola flagellaris are orchids epiphytes, native of Brazil. The in vitro propagation is a technique that allows to produce large numbers of plants, however many losses occur during the period of acclimatization (ex vitro). For this reason, this work aimed to study the effect of supplementation of the Murashige and Skoog medium with paclobutrazol on growth and development of plants of Sophronitis cernua and Brassavola flagellaris (in vitro) to increase the survival rate of seedlings ex vitro. The experimental design was completely randomized. There were four treatments (three concentrations of paclobutrazol: 0.5, 1.0 and 1.5 mg ai L-1 and control) and 10 repetitions with 12 plants. After cultivation in medium without supplementation, the seedlings were inoculated on treatments, where they remained for another 90 days. After this period, five replicates were separated for destructive analysis and the other five were transplanted into trays containing coir (S. cernua) and a mixture of coconut fiber and sphagnum moss (B. flagellaris). It was found that paclobutrazol induced changes in the morphological characteristics of both species. To S. cernua: reducing the number of leaves, leaf area, dry weight and shoot length and increase in diameter and dry mass of roots. Reduction in the rate of seedling survival. To B. flagellaris: increases in dry mass of all parties, except at the highest concentration (aerial part), the number of leaves, leaf area (0.5 mgL-1), diameter, length of roots and more roots. Reduction in the number of shoots and shoot length. Highest survival rates of seedlings
Descrição
Palavras-chave
Flores - Cultivo, Plantas ornamentais - Cultivo, Orquidea - Cultivo, Orquídea - Propagação in vitro, Crescimento (Plantas), orchid, Ornamental plants
Como citar
ICHINOSE, Juliana Garcia dos Santos. Paclobutrazol no crescimento e desenvolvimento in vitro e na aclimatização de Sophronitis cernua (Lindl.) Lindl. e Brassavola flagellaris Barb. Rodr. (Orchidaceae). 2012. iv, 66 f. Tese (doutorado) - Universidade Estadual Paulista, Faculdade de Ciências Agrárias e Veterinárias, 2012.