Banca de QUALIFICAÇÃO: PLÍNIO BEZERRA PALÁCIO

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
DISCENTE : PLÍNIO BEZERRA PALÁCIO
DATA : 19/12/2019
HORA: 14:00
LOCAL: Centro de Ciências Agrárias e da Biodiversidade (CCAB)
TÍTULO:

RHIZOCTONIA ANASTOMOSIS (AG)  GROUPS  ASSOCIATED WITH COWPEA BEANS FROM SOUTH  CEARA STATE BRAZIL

PALAVRAS-CHAVES:

Rhizoctonia. Vignaunguiculata. Anastomosis group. ITS sequences. Phylogeny.

PÁGINAS: 45
GRANDE ÁREA: Ciências Biológicas
ÁREA: Bioquímica
RESUMO:

The fungus of the genus Rhizoctonia causes one of the main diseases of cowpea,
the most important food legume in the Northeast of Brazil and with large planted area in the
South Cearense region, known as Cariricearense. The identification of this fungus is based
mainly on the classification into hyphal anastomosis groups (AGs). Analysis of the internal
transcribed spacer region (ITS) of ribosomal DNA (rDNA) has been the most used for
molecular characterization of most Rhizoctonia AGs. The present study aimed to determine
Rhizoctonia species and AGs that occur in cowpea production areas in Cariricearense using
ITS-rDNA sequencing. Cowpea plants with stem and root rot symptoms, typical of those
induced by Rhizoctonia, were collected in 55 production areas located in 18 municipalities of
Cariricearense, during 2018 and 2019. From symptomatic plant materials were performed
isolations of the associated fungi and obtained Rhizoctoniapure cultures. Genomic DNA was
extracted from all Rhizoctonia isolates and PCR amplifications from the ITS-rDNA region
were made with the ITS1 and ITS4 primers. PCR products were purified and sequenced.
Nucleotide sequences from Rhizoctonia reference isolates obtained from GenBank were
included in the analyzes and phylogenetic relationships were analyzed by Maximum
Likelihood methods. Seventy-sixRhizoctonia isolates were obtained from cowpea areas in
Cariricearense. Phylogenetic analysis of the ITS region allowed the identification of four
AGs, two from R. solani (AG-4 HGI and AG-4 HGIII) and two from Rhizoctoniabinucleate

(AG-Fa and AG-L). This is the first report worldwide of the association of AG-4 HGIII, AG-
Fa and AG-L with cowpea. The identifications of AGs from 35 Rhizoctonia isolates (46.1%)

remain undetermined, since they were grouped in different clades from the currently known
AGs. Among the 41 isolates with identified GAs, AG-4 HGI was the most frequent (53.7%),
being widely distributed in Cariricearense. Among the cowpea producing municipalities in

this region, Mauriti presented the highest diversity of AGs (AG-4 HGI, AG-4 HGIII and AG-
Fa). To our knowledge, this is the first detailed report of the AG composition of

Rhizoctoniaassociated to cowpea in Cariricearense and improves the knowledge on this
subject in Brazil and worldwide.

MEMBROS DA BANCA:
Externo à Instituição - ELIANE MAYUMI INOKUTI - UFRPE
Presidente - 2185176 - FRANCISCO NASCIMENTO PEREIRA JUNIOR
Interno - 1881416 - JUAN CARLOS ALVAREZ PIZARRO
Interno - 2528282 - MARCOS ANTONIO PEREIRA DE LIMA