Development of superior lines of papaya from the Formosa group using the pedigree method and REML/Blup procedure

• Main Authors: Diego Fernando Marmolejo Cortes, Renato Santa-Catarina, Julio Cesar Fiorio Vettorazzi, Helaine Christine Cancela Ramos Ramos, Alexandre Pio Viana, Messias Gonzaga Pereira
• Format: Article
• Language: English
• Published: Instituto Agronômico de Campinas
• Series: Bragantia
• Subjects: Carica papaya; combined selection; segregating populations
• Online Access: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87052019005011102&lng=en&tlng=en

ABSTRACT Developing superior lines based on a simultaneous response from many traits of agronomic importance is a fundamental strategy to expand papaya cultivar supply, mainly the much-needed cultivars belonging to group Formosa. Our goal was to associate the pedigree method with REML/Blup procedure to select plants of progenies F2:3 with superior agronomic performance. The variance components and genetic parameters were estimated using REML approach, and the genetic values were predicted using Blup methodology. The combined selection was performed using the IG2 selection index based on weights associated with agronomic values to indicate the best progenies and lines. The heritability estimates of progeny mean were high in most traits and evidenced significant genetic variability between progenies. The narrow-sense individual heritability was moderate in traits such as commercial fruits and soluble solid contents, which indicates a favorable condition for selections within progenies. The index was consistent in the selection of six superior progenies according to the assessed traits. This index also enabled promising genetic gains in traits of great interest such as yield and pulp thickness. Although the progenies are derived from self generations, they proved to be superior in traits of significant importance such as yield, commercial fruits, and pulp thickness when compared to the Tainung-01 hybrid, which is a worldwide-planted cultivar used as a reference to Formosa representatives. Six lines were selected within the superior progenies to continue the Formosa group-lines development program. The association of the pedigree method with REML/Blup procedure can be useful to assist breeders in an autogamous breeding program.