From lab to nature: acclimatization of Cattleya purpurata (Lindl. & Paxton) Van den Berg, a species considered extinct in São Paulo

• Grant number: 24/13502-9
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: November 01, 2024
• End date: October 31, 2025
• Field of knowledge: Agronomical Sciences - Agronomy - Floriculture, Parks and Gardens
• Principal Investigator: Juliana Lischka Sampaio Mayer
• Grantee: Geovanna Cristina Von Zuben
• Host Institution: Instituto de Biologia (IB). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil

Abstract

Cattleya purpurata (Lindl. & Paxton) Van den Berg is an orchid species endemic to Brazil, distributed in Rio Grande do Sul, Santa Catarina, and São Paulo, in the Atlantic Forest areas. Both habitat loss and high pressure from illegal collection negatively impact the occurrence of the species, which is currently vulnerable to extinction in RS and SC and considered extinct in SP. The project aims to optimize the acclimatization process and maintenance of C. purpurata seedlings from native plant seeds from Bertioga (SP) and Florianópolis (SC), in order to create a plant bank for future reintroductions into natural habitats. After the previously conducted procedures (fruit collection, seed viability testing, asymbiotic germination, and symbiotic germination with the mycorrhizal fungus Tulasnella sp.), a seedling acclimatization protocol will be executed, considering the type of germination performed (asymbiotic or symbiotic), seed origin (SC or SP), the type of seedling support (pot or Pinus slab), and the application or not of a commercial fertilizer. Leaf and root samples will be collected for morpho-anatomical analyses at the beginning of the project and after 2 and 4 months of cultivation, fixed in Karnovsky's solution and stored in 70% ethanol for light and confocal fluorescence microscopies, scanning electron microscopy, and histochemical tests (Lugol for starch and 3% ferric chloride for non-structural phenolic compounds). Variables to be analyzed monthly: survival; growth (height of the aerial part); weight; number of leaves and roots. After 120 days of acclimatization: number of vessel elements and vascular cylinder diameter (roots); stomatal density and mesophyll and cuticle thickness (leaves). Statistical analyses will be performed using R software (normality: Shapiro-Wilk test; three-way ANOVA and Tukey's post hoc test or Kruskal-Wallis test).