Criopreservação de sementes da orquídea brasileira em extinção Cattleya granulosa Lindl.

Abstract

Seed cryopreservation of the endangered Brazilian orchid Cattleya granulosa Lindl. The aim of this study was to evaluate the effect of cryoprotectants in cryopreservation of the orchid Cattleya granulosa Lindl. The experimental design was completely randomized with six treatments and 10 replicates: T1 - without cryoprotective solution; T2-glycerol; T3-sucrose; T4-glycerol + sucrose; T5-PVS2; and T6-PVS2 + 1% phloroglucinol. The seeds were treated with cryoprotectant solutions and immersed in liquid nitrogen at -196 °C. After 15 days, they were removed from the nitrogen and one part was subjected to the tetrazolium test to assess the viability of the embryo, and another was placed in vials for in vitro germination. Seed germination was measured after 60 days by the frequency of protocorm formation. After 180 days we evaluated seedling height and dry mass. The seeds stored in PVS2 and PVS2 + phloroglucinol for 10 minutes at 0°C showed the greatest viability after cryopreservation with 59.56% and 60.10%, respectively.