Banca de DEFESA: VITOR QUINTELA SOUSA
Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.STUDENT : VITOR QUINTELA SOUSA
DATE: 28/02/2023
TIME: 09:00
LOCAL: Auditório da Fitossanidade, Prédio Otávio Gomes
TITLE:
STATUS and characterization of Phthorimaea absoluta (Lepidoptera: Gelicheiidea) resistance to abamectin
KEY WORDS:
Avermectins, tomato pinworm, Tuta absoluta, genetics, sex linkage, polygenic, heritability, diagnostic dose.
PAGES: 61
BIG AREA: Ciências Agrárias
AREA: Agronomia
SUBÁREA: Fitossanidade
SPECIALTY: Entomologia Agrícola
SUMMARY:
The tomato plant Solanum lycopersicum L. is one of the most important fruit vegetables in the world, its main pest is Phthorimaea absoluta (Meyrick). The use of insecticides continues to be important given the enormous destructive capacity of the pest. Among the most used, abamectin has a neurotoxic action and acts on Glutamate receptors. There are reports of resistance to this molecule. This study sought to understand the inheritance of P. absoluta resistance to abamectin. We conducted reciprocal crosses between GVT-Sel and JDR1-Sus. To test the hypothesis of autosomal or sex-linked resistance, using concentration-mortality curves. The results were compared by equality test. To estimate the number of loci influencing resistance, the F1 and F1' progenies were backcrossed with the parents. The mean degree of dominance was calculated using the LC50 values of the F1 and F1ꞌ progenies and the JDR1-Sus and GVT-Sel parents. The results showed that GVT-Sel presented 25939.43x resistance compared to JDR1-Sus, the LC50 value of F1 (0.070) and F1' (0.023), and the equality test showed rejection of the autosomal inheritance hypothesis. The degree of dominance (-0.421) F1, (-0.640) F1' and (-0.531) F1 pooled, exposed incompletely recessive dominance for all crosses. The direct test for the monofactorial model showed significant differences in all backcrosses, indicating rejection of the model. The heritability h2=0.189 was low for GVT-Sel. At effective dominance, 2.5 mg/L of insecticide killed all heterozygous individuals, and the diagnostic concentration was set to 5 mg/L. High cross-resistance occurred with other avermectins and moderately with insecticides from other classes. Emamectin benzoate showed the highest LC50 (21.02 mg/L) and resistance ratio (RR=1,893,000 vezes), and indoxacarb the lowest LC50 (0.729 mg/L) and (RR=0.084 vezes). The female sex-linked resistance emerges as important information. The use of sex pheromones and the use of insecticides with low cross-resistance potential is essential for maintaining the effectiveness of this molecule.
COMMITTEE MEMBERS:
Presidente - HERBERT ALVARO ABREU DE SIQUEIRA
Externa à Instituição - DEBORA BARBOSA DE LIMA MELO - UFPE
Externo à Instituição - JEFFERSON ELIAS DA SILVA
Externa à Instituição - LÍLIAN MARIA DA SOLIDADE RIBEIRO
Externo à Instituição - TADEU BARBOSA MARTINS SILVA - UESPI