Morpho-anatomy of in vitro germination and cryopreservation of the orchid Cattleya crispa (Orchidaceae)

Introduction: Cattleya crispa is an ornamental epiphytic orchid with geographic distribution restricted to the Brazilian Atlantic Forest. Due to predatory extractivism and human-induced habitat loss, this species appears on the Red List of Brazilian Flora.Objective: To characterize morpho-anatomical aspects regarding germination and post-seminal development from C. crispa seeds; as well as studying the effect of cryopreservation on these seeds. Methods: We used light microscopy and electron microscopy to describe the microstructure of a 100 ripe seeds. We evaluated seed viability, seed germination, survival rate and protocorm weight in cryopreserved and non-cryopreserved material, with four replicas per treatment using 20 mg of plant material.Results: The seeds are fusiform, whitish yellow with a length from 700 to 900 & mu;m and a water content of 5 %. Germination began seven days after sowing, the formation of the globular protocorm at 30 days and the formation of the seedling occurred 150 days. The persistent seed coat can compress the protocorm and cause it to collapse. The cryopreserved seeds presented 87.15 % viability, 78.32 % germination, 8.48 % survival and protocorms with 104.27 mg five months after sowing. Data wasn't different to non-cryopreserved seeds.Conclusions: The cryocapability of the seeds shows that cryopreservation can be used for long-term conserva-tion. The results of this work contribute to the overall biology of C. crispa and to the propagation and storage of genetic material for conservation purposes.

Automated summary

This study characterized the morpho-anatomical aspects of germination and post-seminal development of C. crispa seeds, and investigated the effect of cryopreservation on these seeds. The results showed that cryopreservation can be used for long-term conservation of the seeds. These findings contribute to the overall understanding of the biology of C. crispa and the preservation of genetic material.