title: Recombinant near-isogenic lines: a resource for the mendelization of heterotic QTL in maize.
abstract: Although heterosis is widely exploited in agriculture, a clear understanding of its genetic bases is still elusive. This work describes the development of maize recombinant near-isogenic lines (NILs) for the mendelization of six heterotic QTL previously identified based on a maize (Zea mays L.) RIL population. The efficient and inexpensive strategy adopted to generate sets of NILs starting from QTL-specific residual heterozygous lines (RHLs) is described and validated. In particular, we produced nine pairs of recombinant NILs for all six QTL starting from RHLs F(4:5) originally obtained during the production of the RIL population mentioned above. Whenever possible, two different NIL pairs were generated for each QTL. The efficiency of this procedure was tested by analyzing two segregating populations for two of the selected heterotic QTL for plant height, yield per plant and ears per plant. Both additive and dominant effects were observed, consistently with the presence of the QTL within the introgressed regions. Refinement of QTL detection was consistent with previous observations in terms of effects and position of the considered QTL. The genetic material developed in this work represents the starting point for QTL fine mapping aimed at understanding the genetic bases of hybrid vigor in maize.
authors.affiliation: Department of Biomolecular Sciences and Biotechnology, University of Milan, via Celoria 26, 20133, Milan, Italy. giorgio.pea@unimi.it
authors.forename: Giorgio
authors.initials: G
authors.lastname: Pea
authors.forename: Paulinesandra
authors.initials: P
authors.lastname: Paulstephenraj
authors.forename: Maria Angela
authors.initials: MA
authors.lastname: Canè
authors.forename: Maria Luisa Savo
authors.initials: ML
authors.lastname: Sardaro
authors.forename: Pierangelo
authors.initials: P
authors.lastname: Landi
authors.forename: Michele
authors.initials: M
authors.lastname: Morgante
authors.forename: Enrico
authors.initials: E
authors.lastname: Porceddu
authors.forename: Mario Enrico
authors.initials: ME
authors.lastname: Pè
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Frascaroli
mesh_terms: D003433:Crosses, Genetic; D018744:DNA, Plant / Q000235:genetics; D006823:Hybrid Vigor; D018598:Minisatellite Repeats; D010641:Phenotype; D040641:Quantitative Trait Loci; D011995:Recombination, Genetic; D003313:Zea mays / Q000235:genetics*
chemical_list: D018744:DNA, Plant