Inheritance of aluminum tolerance in tropical popcorn using Hayman's diallel analysis

• Ano de defesa: 2020
• Autor(a) principal: Almeida, Vinícius Costa
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Universidade Federal de Viçosa
• Palavras-chave em Português: Milho; Raízes; Melhoramento genético; Melhoramento Vegetal
• Link de acesso: https://locus.ufv.br//handle/123456789/28696

Understanding the genetic control of root growth is essential to improve the aluminum (Al) tolerance in crops. The objective of this study was to investigate the inheritance of Al tolerance related traits in tropical popcorn. Eight inbred lines were crossed in a diallel design and jointly assessed with their F 1 s and two checks in a completely randomized design with two replications. The Al tolerance related traits were Al content, relative and net total, lateral, and axial root length, and number of root tips. The diallel analysis followed the Hayman's proposal. There was dominance for all traits. Only the net axial root length had bidirectional dominance. The dominant genes are not symmetrically distributed between the parents. The dominance was negative for relative total, lateral, and axial root length and positive for the other three traits. In general, there was evidence of complete dominance. Only for the relative lateral root length and net axial root length there were overdominance. None of the assessed inbred lines reached the selection limits. Inbred lines 11-133, 11-403, and 11-383 have the higher number of recessive (favorable) genes for relative total, lateral, and axial root length, respectively. Inbred lines 11-403 and 11-383 also have the higher number of dominant (favorable) genes for reduced Al content. Regarding net total and lateral root length and number of root tips, the inbred line 11-142 has the higher number of dominant (favorable) genes. For net axial root length, the inbred lines 11-109 and 11-133 have more favorable dominant and recessive genes, respectively. Our results evidenced that dominance is an important effect determining popcorn root traits and aluminum content in roots and should be explored in hybrid breeding. Keywords: Aluminum tolerance. Genetic control. Relative root length. Net root length.