Vivas M.,State University of Norte Fluminense |
Da Silveira S.F.,Laboratorio Of Entomologia E Fitopatologia |
Vivas J.M.S.,Laboratorio Of Entomologia E Fitopatologia |
Viana A.P.,State University of Norte Fluminense |
And 2 more authors.
Bragantia | Year: 2014
Landrace genotypes present sources of genes for adaptation, rusticity and resistance to diseases and environmental stress. This study evaluated the potential of landrace papaya genotypes in contributing to phoma-spot resistance genes. The experiment was a randomized block design with six replications consisted of 24 half-sib progenies of dioecious papaya - which segregated for sex. Only plants with female fowers were evaluated. We used mixed models to estimate variance components and the genetic value of landraces to incidence and severity of phoma-spot. Heritability estimates and selective accuracy demonstrated a favorable situation to the selection of resistant progenies,especially ‘STA-02’, ‘STA-04’, ‘STA-05’, ‘STA-06’, ‘STA-07’, ‘STA-11’, ‘STA-12’, ‘STA-16’, ‘STA-21’ and ‘STA-22’, which showed negative values of additive genetic efects for both incidence and severity of phoma-spot. © 2014, Instituto Agronomico. All Rights Reserved.
Marcelo V.,Laboratorio Of Entomologia E Fitopatologia |
da Silveira S.F.,Laboratorio Of Entomologia E Fitopatologia |
Silvas Vivas J.M.,Laboratorio Of Entomologia E Fitopatologia |
Pereira M.-G.,State University of Norte Fluminense
Tropical Plant Pathology | Year: 2013
Landraces are alternatives for widening the genetic base and for incorporation of disease resistance genes in plant breeding programs. For this the use of screening methods capable of efficiently exploiting the available genetic material are needed. With the goal of selecting half-sib families of papaya for a favorable alleles concentration for resistance to black spot, the selection indices of Smith & Hazel, Pesek & Baker, Williams, and Mulamba & Mock were tested. The proposed use of an index aims to seek a more robust alternative to identify genotypes resistant The selection intensity of 41.66% was defined, corresponding to the number of ten progenies. The indices of Mulamba & Mock and Williams have provided gains more suitable for the evaluated characteristics when used the genetic variation coeficient (CVg) as criterion of economic weight. This two methodologies helped select the following progenies 'STA-02', 'STA-04', 'STA-05', 'STA-08', 'STA-13', 'STA-15', 'STA-16', 'STA-17', 'STA-22' and 'STA-24', to compose a new cycle of selection. © The Brazilian Phytopathological Society.