Asymbiotic germination, initial development in vitro and acclimatization of Cyrtopodium paludicolum Hoehne, a Brazilian Savanna orchid species

Abstract

Cyrtopodium paludicolum is a terrestrial orchid species, native to Brazil, whose natural propagation is jeopardized by the intensive collection from the wild and is threatened by agricultural expansion in Cerrado areas. In light of that, this investigation aimed at studying the in vitro germination and early development of C. paludicolum as influenced by culture medium, sucrose and growth regulators as well as its micropropagation by using dark-grown stem segments. A protocol for its acclimatization is also detailed. The effects of Murashige & Skoog (MS), Knudson C (KC) and Vacin & Went (VW) media on the in vitro germination and initial development were tested. The influence of different concentrations of BA, NAA, and of sucrose on plant multiplication and growth were evaluated. The possibility of using etiolated stem segments for micropropagation was also assessed. Acclimatization was accomplished in two phases by using three different substrates. The results showed that VW was the best medium for germination whereas for seedling formation KC was the most advantageous since they were healthy and vigorous. Sucrose at 2% favored the greatest seedling growth and development. Shoot and root proliferation and development were best promoted in the presence of 2.28/2.28 and 0.57/0.57 µM BA/NAA, respectively. The use of etiolated stem segments for micropropagation was effective. Successful acclimatization was accomplished by initially growing plants in community pots containing a 3:1 (v/v) mix of Bioplant and dried Sphagnum moss followed by their transfer to individual pots containing a 2:1 (v/v) mix of Bioplant and Ouro Negro substrates.

In vitro and ex vitro production of Schomburgkia crispa: effect of flask sealing systems and different light sources

“…It is the second largest family among angiosperms. They are distributed in all continents, with a greater concentration and diversity in tropical and subtropical regions (Ferreira et al 2022). In Brazil, there are about 2,677 species of orchids, of which 1,484 are endemic to it (Flora & Funga of Brazil 2022, continuously updated).…”

“…Among the techniques, the in vitro germination of orchid seeds stands out since this type of sowing leads to high percentages of germination compared to germination under natural conditions, which occurs only in the presence of mycorrhizal fungi (Zhang et al 2018;Soares et al 2020;Kumar et al 2022). In this sense, the production of orchids by that method is important, as it allows a large number of seedlings to grow in a small space, in a short time, and with a high sanitary quality (Teixeira da Silva et al 2015Silva et al , 2017aFerreira et al 2022;Pereira et al 2022;Nowakowska et al 2022).…”

Morfogênese in vitro de plântulas de Cattleya intermedia Graham ex Hook (Orchidaceae) em diferentes concentrações de meio de cultura basal

“…O desenvolvimento de protocolos para o crescimento inicial in vitro de orquídeas tem sido obtido com a avaliação de diferentes composições salinas, incluindo diferentes meios de cultivo e concentrações dos mesmos visando a conservação da espécie e a utilização em biofábricas de plantas (Araujo et al, 2009;Suzuki et al, 2010;Juras et al, 2019, Ferreira et al, 2022. Geralmente, o nitrato é a forma de nitrogênio mais facilmente absorvida pelas plantas, embora isso possa variar entre as espécies e pode ser influenciado por fatores ambientais (Mengel & Kirkby, 1978).…”

Developing Paraphalaenopsis labukensis (Shim, A. Lamb & C.L. Chan), an Orchid Endemic to Sabah, Borneo, Asymbiotic Seed Germination and In Vitro Seedling Development

“…Successful asymbiotic seed productions of several wild orchids have been reported, including Eulophia alta [10], Bletilla striata [11], Cyrtopodium paludicolum [12], (Spathoglottis plicata [13], Cremastra appendiculata (D. Don) Makino [14], and Paphiopedilum tigrinum [15]. Other essential elements influencing the success of in vitro asymbiotic seed cultivations and protocorm development include macro and micro element compositions, vitamins, sucrose, nitrogen, carbohydrates, and organic nutrients [16][17][18].…”