In vitro seed germination and seedling growth of the orchid Dendrobium primulinum Lindl.

Abstract

Dendrobium primulinum Lindl. (D. Primulinum L.) is one of the important epiphytic orchid species for horticultural and commercial use. It is listed as a rare and critically endangered species of orchid. The present study is intended to conserve the orchid species through the micropropagation technique. The in vitro seed germination and seedling growth was carried out by taking a mature pod of D. Primulinum L. in Murashige and Skoog (MS) media, and the MS media supplemented with a varied concentration (0.5, 1.0, 1.5 and 2 mg/L) of 6-benzylaminopurine (BAP), and a fixed concentration (0.5 mg/L) of αnaphthalene acetic acid (NAA). Sequential phases of seed germination, protocorm formation, and seedling development in the presence of growth regulators were determined in the study. The significance of hormonal effects was determined by using One-Way Analysis of Variance (ANOVA, p≤0.05). The seed germination started after two weeks of culture in the media supplemented with BAP. The maximum seedling growth was obtained in the media supplemented with 1.5 mg/L of BAP. Although the hormone-free basal medium revealed an ideal condition for seed germination and spherules formation, the presence of an appropriate concentration of growth regulators such as 0.5 mg/L NAA or a combined 0.5 mg/L BAP + 0.5 mg/L NAA expressed a synergistic effect to enhance the protocorm formation and seedling development.

Cultivo in vitro de Peltophorum dubium (Spreng.) Taub y Enterolobium contortisiliquum (Vell.) Morong

“…En P. dubium, la máxima frecuencia de germinación y altura promedio de las plántulas se obtuvo en las semillas germinadas en medio MS½ en presencia de 0,1 mg/l de BAP; mientras que en E. contortisiliquum los valores máximos de germinación y altura de plántulas se observó en medio MS libre de BAP. En P. dubium pudimos observar un efecto positivo de la presencia del BAP en el medio de germinación, tanto en la capacidad germinativa, como en el desarrollo posterior de las plántulas in vitro, en concordancia a lo demostrado por Asif et al (2001); Nikolić et al (2006); Akram & Aftab (2015); y Hira & Bijaya (2019). Sin embargo, en la mayoría de las publicaciones especificas en P. dubium, la germinación in vitro de las semillas se realizó en agar-agua sin macro, micronutrientes, ni RCV (Bassan et al, 2006;Curti, 2011;Flôres et al, 2011;Candido, 2013;Gomes, 2017;Andreolla, 2019), solamente Fruet (2018) menciona el uso de MS½ enriquecido con 30 g/l de sacarosa en la germinación de las semillas de P. dubium; pero ninguno abordó el estudio del efecto del medio nutritivo en la germinación.…”

Germination and initial development in vitro, and acclimatization of Oeceoclades maculata (Orchidaceae), aiming at its reintroduction in natural environments

“…Different results were obtained by Mahendran, Muniappan, Ashwini, Muthukumar, and Bai (2013) who reported that increasing BA concentration from 1 to 2 mg L -1 caused a decrease in shoot formation of Cymbidium bicolor. In different orchid species it has been demonstrated that organogenesis and growth are highly favored by the interaction of auxin and cytokinin (Picolotto et al, 2017;Adhikari & Pant, 2019).…”

Effect of Benzyl Amino Purine (BAP) on the Leaf Growth of Vanda limbata Blume Orchid In Vivo

“…PGR are chemical substances that affect the growth and differentiation of plant cells, tissues and organs (Hira and Bijaya, 2019). One method that can be done to increase shoot growth is the addition of cytokinins.…”