Artificial seed of Dendrobium macrophyllum var. ternatense (orchidaceae): Interim storage at cold storage

Dendrobium macrophyllum var. ternatense is one of the potential orchids that have limited distribution. This species is threatened by forest degradation, illegal logging, and over exploitation by society. The conservation effort is needed to prevent the loss of genetic diversity through the encapsulation techniques to produce artificial seeds. This study aims to determine the proper combination concentration of sodium alginate (SA) as matrix encapsulation and calcium chloride (CC) as a complexing agent and also to observe the effect of the storage interval of the artificial seed in the low temperature (4°C). The concentrations used were 2-4% of SA and 75 and 100 mM of CC. The storage interval was 1-8 weeks in the refrigerator. The result shows that the qualified artificial seed can be produced by using 4% of SA and 75 mM of CC. The 5 weeks storage interval of the artificial seed of D. macrophyllum var. ternatense gave the higher germination rate, the highest plant height, fastest leaf formation time, and the most leaves number. Overall, the artificial seeds then can be stored for up to 8 weeks at low temperatures (4°C).