African Journal of
Biotechnology

  • Abbreviation: Afr. J. Biotechnol.
  • Language: English
  • ISSN: 1684-5315
  • DOI: 10.5897/AJB
  • Start Year: 2002
  • Published Articles: 12196

Full Length Research Paper

Selection of loose-leaf lettuce breeding lines based on non-parametric indexes

Willame dos Santos Candido
  • Willame dos Santos Candido
  • Universidade Federal de Goiás (UFG), Regional Jataí, Rua Riachuelo, Jataí, Goiás, Brasil.
  • Google Scholar
Dora Enith Tobar-Tosse
  • Dora Enith Tobar-Tosse
  • Faculdade de Ciências Agrárias e Veterinárias (FCAV), Universidade Estadual Paulista (UNESP), Jaboticabal, São Paulo, Brasil.
  • Google Scholar
Renato Silva Soares
  • Renato Silva Soares
  • Faculdade de Ciências Agrárias e Veterinárias (FCAV), Universidade Estadual Paulista (UNESP), Jaboticabal, São Paulo, Brasil.
  • Google Scholar
Lucas da Silva Santos
  • Lucas da Silva Santos
  • Departamento de Agronomia, Universidade Federal Rural da Amazônia (UFRA), Capanema, Pará, Brasil.
  • Google Scholar
Carolina Andrade Franco
  • Carolina Andrade Franco
  • Faculdade de Ciências Agrárias e Veterinárias (FCAV), Universidade Estadual Paulista (UNESP), Jaboticabal, São Paulo, Brasil.
  • Google Scholar
Leila Trevisan Braz
  • Leila Trevisan Braz
  • Faculdade de Ciências Agrárias e Veterinárias (FCAV), Universidade Estadual Paulista (UNESP), Jaboticabal, São Paulo, Brasil.
  • Google Scholar


  •  Received: 30 July 2017
  •  Accepted: 21 September 2017
  •  Published: 04 October 2017

Abstract

Non-parametric selection indexes (that is, require no estimation of parameters) can be used to help the selection process in the final stage of genetic enhancement. In this context, the objective of this study was to evaluate the efficiency of non-parametric selection indexes to choose promising lineages of loose-leaf lettuce, so that genetic gain of each lineage can be estimated and then registered in the Ministry of Agriculture. The indexes of Mulamba and Mock, Elston and Schwarzbach were used in the analysis. Ten genotypes of loose-leaf lettuce were evaluated, with eight of them being lineages (L1, L2, L3, L4, L5, L6, L7, L8) and two commercial cultivars (Vanda and Vera). The experiments occurred in six different locations of cultivation during the autumn and winter seasons of 2014. Experimental delineation was composed of random blocks, with four repetitions and the evaluated characteristics were: total production, commercial production, number of leaves, plant volume and stem length. The effects of genotype (G), location (L), and G x L interaction were significant for all characteristics. Indexes were correlated to classify the genotype. The Mulamba and Mock index stood out because it enabled good direct gains for the evaluated characteristics and because of its easy construction. Therefore, this index is recommended for selection of loose-leaf lettuce genotypes in the stage of cultivar recommendation in different locations. As the best lineages of loose-leaf lettuce were L2, L3, L7 and L8, these lineages have been considered promising and are recommended for registration.

 

Key words: Agronomic performance, Lactuca sativa, nonlinear indexes, spearman correlation.