Use of complex supplements and light-differential effects for micropropagation of Hadrolaelia purpurata e Encyclia randii

In the current study, complex (coconut water and ripe-banana pulp) and specific (micronutrients, peptone and activated charcoal) supplements were added to Knudson-C medium (KC) medium to stimulate the in vitro propagation of Hadrolaelia purpurata (=Laelia purpurata) and Encyclia randii orchid species. The highest number of H. purpurata seedlings occurred in KC medium containing 90 g [L.sup.-1] banana pulp maintained with 24-hour illumination. Positive effects of the banana pulp addition in KC medium were reported for the formation of seedlings and leaves from E. randii seeds. The seedling number from seeds of E. randii maintained with continuous illumination was also high in KC medium containing coconut water. Positive effects due to the addition of peptone were reported only in the case of seedling formation from E. randii seeds maintained under continuous illumination. The highest number of H. purpurata seedlings and leaves of E. randii occurred in cultures maintained in continuous illumination. The successful asymbiotic germination of the three-year-old seeds of two Brazilian native species from different regions at reduced costs offers an opportunity for the use of the techniques in commercial nurseries and for ex situ conservation of the native and explored orchid species. Keywords: asymbiotic seed germination, banana, coconut water, peptone, micronutrients, Orchidaceae. No presente estudo foram adicionados ao meio de cultura Knudson-C (KC), suplementos especificos (micronutriente, peptona, carvao ativado) e complexos (agua de coco e polpa de banana) para estimular a propagacao in vitro das especies de orquideas Hadrolaelia purpurata (=Laelia purpurata) e Encyclia randii. O numero maior de plantulas de H. purpurata foi observado no meio KC contendo 90 g [L.sup.-1] de polpa de banana com iluminacao continua (24h). O efeito positivo da adicao de polpa de banana foi descrito para a formacao de plantulas e folhas de E. randii. O numero de plantulas de E. randii mantidas com iluminacao continua tambem foi alto em meio contendo agua de coco. Um efeito positivo da adicao de peptona foi descrito somente na formacao de plantulas de E. randii mantidas sob iluminacao continua. O maior numero de plantulas de H. purpurata e folhas de E. randii ocorreu com iluminacao continua. O sucesso na germinacao assimbiotica de sementes com tres anos de idade, das duas especies de orquideas nativas do Brasil, de regioes diferentes, com custo reduzido, e uma tecnica oportuna pa