Banca de DEFESA: POLIANA FERREIRA SANTOS

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : POLIANA FERREIRA SANTOS
DATE: 20/02/2026
TIME: 09:00
LOCAL: Auditório do PPG em Ciência do Solo
TITLE:

Screening of Metal Hyperaccumulators in Brazilian Herbaria Using Portable X-ray Fluorescence

KEY WORDS:

Herbarium specimens. pXRF. Hyperaccumulation. Ionome. Brazilian metallophytes.

PAGES: 51
BIG AREA: Ciências Agrárias
AREA: Agronomia
SUBÁREA: Ciência do Solo
SPECIALTY: Química do Solo
SUMMARY:

Metal hyperaccumulator plants constitute key models for understanding stress tolerance mechanisms and for the development of phytotechnologies. However, the identification of such species in Brazil remains limited due to the lack of large-scale screening efforts. This study aimed to identify native hyperaccumulators of aluminum (Al), cobalt (Co), manganese (Mn), nickel (Ni), and zinc (Zn) in herbarium collections through screening using portable X-ray fluorescence (pXRF). A total of 3,405 herbarium specimens, representing 138 families, 617 genera, and 1,052 species, were scanned by pXRF using calibration suitable for herbarium material. Based on historical hyperaccumulation thresholds, 20 families were identified as potentially hyperaccumulative for Al, of which Marattiaceae, Vochysiaceae, and Melastomataceae were confirmed by inductively coupled plasma optical emission spectrometry (ICP-OES). No family exceeded the hyperaccumulation threshold for cobalt. Manganese concentrations above 10,000 mg kg⁻¹ were confirmed in Onagraceae and Aquifoliaceae, representing the first records of these families as Mn hyperaccumulators in Brazil. A new Ni hyperaccumulator was also confirmed within the family Lamiaceae. Only one representative of Malvaceae exhibited Zn concentrations above 3,000 mg kg⁻¹; however, this value was not confirmed by ICP-OES. In addition, the application of empirical thresholds allowed the identification of 6 families potentially hyperaccumulative for Co, 19 for Mn, 2 for Ni, and 31 for Zn, including Capparaceae, Aquifoliaceae, and Verbenaceae as potential simultaneous hyperaccumulators of Co and Zn, as well as Mn and Zn. These results substantially expand current knowledge on metal hyperaccumulation in the Brazilian flora and open new perspectives for studies on evolution, adaptation, and the application of these species in phytotechnologies.

COMMITTEE MEMBERS:
Presidente - CLISTENES WILLIAMS ARAUJO DO NASCIMENTO
Externo à Instituição - DANILO SOARES GISSI
Externo à Instituição - VENÂNCIO DE LIMA VELOSO