Superoxide dismutase (SOD) for the identification of recalcitrance in cocoa seeds (Theobroma cacao L.)

• Grant number: 21/13689-3
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: February 01, 2022
• End date: January 31, 2023
• Field of knowledge: Agronomical Sciences - Agronomy - Crop Science
• Principal Investigator: Victor Augusto Forti
• Grantee: Isadora de Andrade Tronco
• Host Institution: Centro de Ciências Agrárias (CCA). Universidade Federal de São Carlos (UFSCAR). Araras , SP, Brazil

Abstract

Cocoa is a recalcitrant species because its seeds after physiological maturity do not suffer natural desiccation and are dispersed with high moisture content. One of the difficulties for the conservation of recalcitrant species is the lower tolerance to low temperatures and low moisture contentes which prevents it from surviving for long periods of storage. This sensitivity during storage is related to the inefficient response of defense mechanisms to stressful conditions. These mechanisms, such as antioxidant enzymes (for example, superoxide dismutase - SOD), are responsible for removing the free radicals that cause cell death. Thus, the present work aims to determine the activity of the enzyme Superoxide dismutase (SOD) as a biochemical marker of desiccation sensitivity in cocoa seeds (Theobroma cacao L). For this, two lots of cocoa seeds, extracted from ripe fruits, will be subjected to continuous drying in an oven with forced air circulation at 34 ± 2 °C to obtain treatments with different water contents. The seeds of each treatment will be evaluated for moisture content and for physiological potential through the germination test and the tetrazolium test. In addition, the seeds of all treatments of both lots will be submitted to biochemical analysis to evaluate the activity of the SOD enzyme. The use of biochemical analysis of SOD enzyme activity, as a marker of desiccation sensitivity, can be an alternative to complement tests for evaluating recalcitrance.(AU)