Rhipsalis (Cactaceae) seed germination in different temperatures and water potentials.

• Grant number: 22/10793-7
• Support Opportunities: Scholarships in Brazil - Master
• Start date: November 01, 2022
• End date: September 30, 2024
• Field of knowledge: Biological Sciences - Botany - Pant Physiology
• Principal Investigator: Odair José Garcia de Almeida
• Grantee: Rafael Reis Gonçalo
• Host Institution: Instituto de Biociências (IB-CLP). Universidade Estadual Paulista (UNESP). Campus Experimental do Litoral Paulista. São Vicente , SP, Brazil

Abstract

Distributed throughout the American continent, Cactaceae is a very representative group of plants (>1800 described species), which presents a great variety of habits and life forms. It currently ranks fifth globally as the most threatened taxon, at risk of losing up to 60% of its species in the coming decades as a result of climate change. About 10% of the cacti are epiphytic, with greater diversity concentrated in the Atlantic Forest of southeastern Brazil, a biome very devastated by anthropic action. However, the number of studies focused on the germination of these species is still scanty. Among the environmental factors predicted to be more likely to restrict the occurrence of cacti in the future are temperature and water availability, and direct consequences of climate change, especially in the early stages of development. In this context, germination is the stage in which the plant is very susceptible, and its characterization and the investigation of the environmental factors that affect it are fundamental to understanding its ecophysiology. It has been known that epiphytic cacti may be exposed to water deficit in their fixing substrates and little is known about their germination profile in relation to temperature This proposal intends to evaluate the effect of different values of water potential on the germination and viability of seeds of Rhipsalis, a genus of epiphytic cacti, collected from natural populations, and to characterize their germination at different temperatures. The data obtained in this research will contribute to a better understanding of the reproduction and ecophysiology of this group of plants, still little studied, calling attention to their conservation and natural habitats in the face of future climate scenarios.