Anatomical changes and starch allocation in response to the fire in Urochloa brizantha R.D. Webster

• Grant number: 15/01380-7
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: December 01, 2015
• End date: November 30, 2016
• Field of knowledge: Biological Sciences - Botany - Plant Morphology
• Principal Investigator: Aline Redondo Martins
• Grantee: Patrícia Fernanda Rosalem
• Host Institution: Faculdade de Engenharia (FEIS). Universidade Estadual Paulista (UNESP). Campus de Ilha Solteira. Ilha Solteira , SP, Brazil
• Associated research grant: 15/06743-0 - How does fire season affect Cerrado vegetation?, AP.JP

Abstract

The Cerrado is a 'hotspot' of global biodiversity, with diverse flora with adaptations to fire, such as thickened underground stems that regrowth after action of fires, perennial herbs, flowering and fruiting with specialized phenologies to the dynamics of fire. Its original area was very destroyed or converted to other uses such as pasture and crops, using some exotic grasses that have become invasive. One of the most common invasive is Uroclhoa brizantha that changes the Cerrado environment considerably reducing its natural diversity. The objective of this study is to evaluate the carbon allocation in U. brizantha in controlled treatments of use of fire (biennial burning, annual and control) in the field. In addition, we have to analyze changes in epidermal thickness and leaf mesophyll in the different treatments. Therefore, the leaf samples will be fixed in FAA 50, dehydrated in an ethanol series, embedded in hydroxyethyl methacrylate (LeicaHistoresin) and the specimens will be sectioned into 5-10 µm of thickness. The blades will be then stained with 0.05% toluidine blue in phosphate buffer and citric acid (pH between 4.5-6.0) and covered with synthetic resin "Entellan" and cover slip. The carbon is analyzed in leaves and rhizome by histochemistry tests for the detection of starch, such as Lugol iodine and zinc chloride on slides that will be prepared from samples of the different treatments. Starch quantification (carbon) is also determined by chemical analysis.