In vitro germination of Zigopetalum maculatum with different disinfection protocols and addition of coconut water to the culture media

Abstract

Orchid seeds lack endosperm and under natural conditions must be associated with mycorrhizae, whose germination percentage does not exceed 5 %. In this sense, the objective of the present work was to evaluate the viability and asymbiotic germination of Zigopetalum maculatum by means of three disinfection protocols in two culture media. The disinfectant treatments consisted of immersing the seeds in 0.5 % NaClO for five minutes, half of which were placed in tea bags and the other half in a syringe, and the capsule (fruit) was disinfected in 1 % NaClO for five minutes. Subsequently, it was seeded in MS with 10 and 20 % coconut water. The design used was a DCA with 15 replicates. The percentage of viability, germination, contamination and developmental stages of the germination process (F1, F2, F3 and F4) were evaluated. The viability percentage of Z. maculatum was 68.7%. The disinfection treatments on seeds in paper envelopes and fruits were statistically similar, 5 and 10 % contamination in the media with 10 and 20 % coconut water, respectively. Of the disinfectant treatments, the seeds reached more advanced stages (F3 and F4) than those disinfected in the fruit. The highest germination percentage was 98 % in MS medium with 10 % coconut water and seed disinfection in tea sachet (0.5 % NaClO for five minutes). The use of in vitro culture was efficient for the germination and regeneration of Z. maculatum, which provides an alternative to reduce the pressure exerted on wild populations, contributing to their conservation and sustainable use.