Influences of Organic Additives on Asymbiotic Seed Germination of Dendrobium cruentum Rchb. f. for In Vitro Micropropagation

Abstract

Dendrobium cruentum Rchb. f., a commercial orchid in Thailand, faces the risk of extinction and should be conserved, and propagated for commercial. Therefore, the aim of this research was to identify a suitable VW medium supplemented with organic additives for the micropropagation of D. cruentum through asymbiotic seed germination. The VW media supplemented with separate organic additives (coconut water (CW) (100 mL/L), ‘Hom Thong’ banana homogenate (BH) (1000 mg/L), and potato homogenate (PH) (1000 mg/L) or its combination was determined, and the seed germination rate (%), protocorm formation, and plantlet development were observed. The results showed that a combination of BH and PH resulted in the highest seed germination (94.69 ± 1.55 %) when compared to basal VW (control). Protocorm formation was highest with CW alone (47.38 ± 7.17 %) and a combination of CW and PH (52.13 ± 6.20 %). Additionally, after 10 weeks of culture, supplementation with BH yielded the highest number of plantlets. However, after 24 weeks of culture, each organic additives gave the different developments of healthy plantlets. To investigate suitable potting media for acclimatization of well-grown plantlets in greenhouse conditions, 2 pieces of foam, dried coconut husk, and a combination of peat moss: Sphagnum moss: Pumice: Perlite (3:1:1:1) were investigated. The highest survival rate percentage was found in foam-planted plantlets (80 %). Ultimately, the effectively simple mediums containing organic additives and a one-step protocol were provided for the micropropagation of D. cruentum via seeds, and the derived information could be used for D. cruentum conservation and production. HIGHLIGHTS The effects of organic additives on asymbiotic seed germination for in vitro micropropagation of Dendrobium cruentum Rchb. f. was firstly reported The media supplemented with organic additives yield significantly the highest seed germination, protocorm formation, and plantlet formation and development of D. cruentum when compared to basal media In greenhouse conditions, 2 pieces of foam gave the highest survival rate percentage of plantlets (80 %) The practical and beneficial media supplemented with organic additives for micropropagation of D. cruentum was provided GRAPHICAL ABSTRACT