Precocious flowering of plants resulting from in vitro germination of Cycnoches haagii seeds on mycorrhizal fungi presence

Abstract

Cycnoches haagii is an epiphytic Orchidaceae found in the Brazilian Savannah that presents a great ornamental potential. Aiming at developing a complete seminal propagation protocol of C. haagii, as well as testing the influence of the mycorrhizal fungi presence in the process, mature seeds were germinated in vitro in the presence or absence of two fungal isolates, both belonging to the Tulasnella genus (FCH and FHC3E), in three culture media (B&G, Knudson and OMA). The percentage of germinated seeds was evaluated, and the protocorms of the four media with higher percentages were transferred to a new media, aiming at the conversion into plantlets. The seedlings were evaluated for shoot length, number of leaves, length of the largest root, number of roots and total fresh matter. The B&G medium provided a germination rate higher than 60 %, besides a higher seedling growth, contributing to 100 % of survival in the acclimatization stage, independently of the mycorrhizal fungi presence. However, only the seedlings from the B&G medium inoculated with the isolated FHC presented a fast growth when acclimatized, and flowering at the end of the first year of acclimatization. Therefore, the presence of the mycorrhizal fungus FHC on the B&G medium, during the germination phase, is adequate for the propagation of C. haagii, because it accelerates its development and anticipates the ex vitro flowering.