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Molecular marker assisted selection using the AB-QTL method and genotyping by sequencing (GBS) toward angular leaf spot and antracnose resistance in common beans

Grant number: 14/11145-2
Support type:Regular Research Grants
Duration: October 01, 2014 - December 31, 2017
Field of knowledge:Agronomical Sciences - Agronomy - Crop Science
Principal Investigator:Luciana Lasry Benchimol-Reis
Grantee:Luciana Lasry Benchimol-Reis
Home Institution: Instituto Agronômico (IAC). Agência Paulista de Tecnologia dos Agronegócios (APTA). Secretaria de Agricultura e Abastecimento (São Paulo - Estado). Campinas , SP, Brazil
Assoc. researchers:Alisson Fernando Chiorato ; Sérgio Augusto Morais Carbonell

Abstract

Among the common bean diseases of the, the angular leaf spot (ALS) and anthracnose (ANT) cause reduction in the yield and the quality of grain produced, and due to the great variability of these pathogens, a durable resistance of many cultivars was not achieved. A large number of molecular markers were associated with QTLs for resistance to this disease by our group of research. According to studies of our research group, ALS and ANT showed quantitative inheritance and several QTLs should be introgressed in order to produce a lasting resistance to different races of the pathogen. The AB-QTL (Advanced backcross QTL Analysis) technique is able to select, introgress and simultaneously map the QTLs, through backcrossing, and therefore the effects (epistatic and pleiotropic) of the combination of different QTLs can be measured, and only the QTLs favorable are transferred, without losing the quality of elite cultivar used as the recurrent parent. While the other methods of assisted selection are based on first performing the mapping of the QTLs for then transferring those that are favorable, the AB-QTL method suggests evaluating simultaneously the families and/or progenies that phenotypically superior together with the introgression of QTLs, reducing the problem of linkage drag and negative interactions. Phenotypic selection eliminates the progenies with lower performance; even those that have favorable QTLs introgressed, but can have their values changed by genetic epistatic, pleiotropic effects or by genotype x environment interactions. The objective of this project is to use the technique of AB-QTL to promote a gain on the genetic resistance to ALS in common bean breeding program of the Agronomic Institute of Campinas (IAC). For ALS, the 'IAC Milênio' cultivar (susceptible, recurrent parental) will be crossed with the 'AND 277' cultivar (resistant, parental donor) while for ANT, the 'Pérola' (susceptible, recurrent parent) cultivar will be crossed to the 'IAC-Formoso' (resistant, donor parent) cultivar. Phenotypical selection of plants that have desirable agronomical patterns for common bean will be made in RC1 and RC2, and evaluation with molecular markers in large scale will occur in F2BC22. In this generation, the QTLs will be mapped using GBS, useful for the detection and selection of a high number of SNP markers, and near isogenic lines (QTL-NILs) will be evaluated. The disease phenotyping will be taken in the greenhouse during mapping, but then the selection will be conducted in experimental field conditions with natural infection. It is expected that new cultivars may be recommended for the common bean breeding program of the IAC and that they show effective resistance in harvesting conditions. (AU)