Banca de QUALIFICAÇÃO: Izaias Araujo de Oliveira

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : Izaias Araujo de Oliveira
DATE: 28/09/2022
TIME: 08:00
LOCAL: Videoconferência
TITLE:

Metagenomic analysis of the diversity of Geminiviridae species and subviral agents infecting tomato in different Brazilian biomes and production of infectious begomovirus clones.

KEY WORDS:

Geminiviridae, Solanum lycopersicum, high-throughput sequencing, tolerance.

PAGES: 143
BIG AREA: Ciências Biológicas
AREA: Biologia Geral
SUMMARY:

The tomato crop (Solanum lycopersicum L.) is of great importance for national and international agriculture. Several viruses can affect this vegetable crop causing considerable impacts. Among the viruses that infect tomato, isolates from species classified within the genus Begomovirus (family Geminiviridae) deserve to be highlighted. Begomoviruses have single-stranded circular DNA genomes that can be mono- or bipartite which are separated into two large groups: begomoviruses from the Old World and from the New World. Transmission of begomoviruses occurs via a complex of cryptic species of Bemisia tabaci (Aleyrodidae, Hemiptera) predominantly B. tabaci Middle East Asia Minor 1 – MEAM 1 (former biotype B) and B. tabaci Mediterranean MED (former biotype Q). The range of host plants for begomoviruses is wide, including cultivated and uncultivated dicots. There is a great diversity of begomovirus species already described; and several new species have been characterized in the last decade. This increasing begomovirus variability occurs via three distinct mechanisms: mutation, recombination and reassortment. One of the promising strategies to control begomoviruses is the use of cultivars with resistance/tolerance. With the increasing diversity of species, the use of tools such as High-Throughput Sequencing (HTS) has allowed the large-scale study of viral diversity. Such studies have already shown that tomato plants that carry the Ty-1 gene reduce the number of begomoviruses that infect tomato plants and impact the frequency and prevalence of these viruses, acting as a ‘filter’ on these in tolerant cultivars. In addition, new and/or recombinant species can overcome tolerance factors present in the host plant. The DF-640 isolate is an example, which was recently described by our research team. The present work aims to expand the studies of viral diversity and the impact of tolerant tomato cultivars on the population dynamics of begomoviruses at a nationwide level, since these analyzes are still restricted to the central regions of Brazil. Thus, this work aims to analyze, through HTS, the diversity of begomovirus populations across all five macrogeographic regions of Brazil in plants with and without tolerance factors, as well as the detection and biological and molecular characterization of new viral species. Infectious clones will be obtained to study the host range and confirm the virulence profile of newly described begomoviruses. It is expected to contribute to breeding programs by offering a more precise overview of the diversity of begomoviruses occurring in Brazil in tomato cultivars with and without tolerance factors, as well as generating infectious clones of at least two new species and species widely spread across the country.

BANKING MEMBERS:
Externo à Instituição - AILTON REIS - EMBRAPA
Interno - 1701961 - CLEBER FURLANETTO
Interno - 1351999 - LUIZ EDUARDO BASSAY BLUM
Externo à Instituição - RENATO DE OLIVEIRA RESENDE - UnB
Presidente - 1723060 - RITA DE CASSIA PEREIRA CARVALHO
Interno - 2644635 - ROBERT NEIL GERARD MILLER