QTL analyses for seed iron and zinc concentrations in an intra-genepool population of Andean common beans (Phaseolus vulgaris L.)

Abstract

Legumes provide essential micronutrients that are found only in low amounts in the cereals or root crops. An ongoing project at CIAT has shown that the legume common bean is variable in the amount of seed minerals (iron, zinc, and other elements), vitamins, and sulfur amino acids that they contain and that these traits are likely to be inherited quantitatively. In this study we analyzed iron and zinc concentrations in an Andean recombinant inbred line (RIL) population of 100 lines derived from a cross between G21242, a Colombian cream-mottled climbing bean with high seed iron/zinc and G21078, an Argentinean cream seeded climbing bean with low seed iron/zinc. The population was planted across three environments; seed from each genotype was analyzed with two analytical methods, and quantitative trait loci (QTL) were detected using composite interval mapping and single-point analyses. A complete genetic map was created for the cross using a total of 74 microsatellite markers to anchor the map to previously published reference maps and 42 RAPD markers. In total, nine seed mineral QTL were identified on five linkage groups (LGs) with the most important being new loci on b02 and other QTL on b06, b08, and b07 near phaseolin. Seed weight QTL were associated with these on b02 and b08. These Andean-derived QTL are candidates for marker-assisted selection either in combination with QTL from the Mesoamerican genepool or with other QTL found in inter and intra-genepool crosses, and the genetic map can be used to anchor other intra-genepool studies.

Linkage disequilibrium based association mapping of micronutrients in common bean (Phaseolus vulgaris L.): a collection of Jammu & Kashmir, India

“…Earlier bi-parental approach also identified the QTLs for mineral concentration in common bean. One of the marker BM185 which was identified as QTL for Fe in RIL population derived by G21242 9 G21078 (Blair et al 2011) was found to be associated with Fe in our study and this validates our results. Moreover, the associated markers identified in this study are found located on chromosomes in which earlier QTLs were detected.…”

Genetic variability for iron and zinc content in common bean lines and interaction with water availability

“…The extent of the correlation varied widely among the different experiments and ranged from no association to intermediate association, indicating the influence of environment and other associations on these characteristics. The results were similar to those found in other studies (Guzman-Maldonado et al, 2003;Gelin et al, 2007;Cichy et al, 2009;Blair et al, 2009Blair et al, , 2011) that examined recombinant lines obtained from crosses between one parent with high CFe and CZn and another with low levels of these minerals. In contrast, some studies using lines with different genetic backgrounds showed that this relationship does not exist (Ribeiro et al, 2008), while others reported a significant relationship (Welch et al, 2000;Silva et al, 2012) between the levels of the two minerals.…”

Nutritionally Enhanced Staple Food Crops

“…Seed weight QTL were associated with these on b02 and b08 Blair et al 2011 A set of across site, overlapping iron and zinc QTL were discovered for a Mesoamerican  Mesoamerican mapping population on LG b06 suggesting a possibly pleiotropic locus and common physiology for mineral uptake or loading. Other QTL for mineral concentration or content were found on LGs b02, b03, b04, b07, b08, and b11…”

“…For example, with increased seed size, the amount of the mineral will be diluted compared to low seed size if the amount of mineral nutrient is fixed. Blair et al (2011) pointed this out in a comparison of content versus concentration among various legumes where model legumes have tended to be small seeded while crop legumes are large seeded, especially as with Andean common beans. This is especially true if there is variability among seed tissues such as the seed coat, embryo, or cotyledonary tissue, unless compensation between these tissues occurs (Ariza-Nieto et al 2007).…”