Descripción: INIA maize Germplasm Collection contained approximately 1200 maize accessions. Most of the collection are landraces that are not the product of modern plant breeding. The accessions in the Collection could be potencial sources of genes for maize improvement not just in the country, but worldwide. Landraces are important reservoirs of new genes for yield, climatic resielence, and food quality, with nutritional and health benfits.In Chile 23 maize landraces were currently grown. These landraces are particularly important from the genetic perspective because they were grown under contrasting environmental conditions. The Chilean landraces thus represent an important element to explore the evolution of the maize genome and could act as a genetic reservoir for further adaing crops to new conditions. However, in order to conserve, monitor and better use this variation it is necessary to understand it at its molecular and eco-geographical levels. The efficient utilization of plant genetic resources is frequently limited by incomplete phenotypic data for traits of interest, which makes the targeted selection of putative useful accessions from large germplasm collections very challenging. The Focused Identification of Germplasm Strategy (FIGS) promises a solution to this phenotyping bottleneck for traits associated with environmental adaation. FIGS has been successfully used in Hordeum vulgare for agro-morphological characteristics and time of heading and maturity, Triticum aestivum for resistances to powdery mildew and stem rust, and Vicia faba for drought tolerance Maize, third most important staple cereal crop across the globe, has been threatened with different environmental constraints including heat and water deficit stress. Higher environmental temperatures negatively affect the most at anthesis, silking and grain filling reproductive phenophases. The situation is further complicated by the variable climatic events, resulting in gradual and sometimes sudden increase in environmental temperature followed by irregular rain/irrigation frequency and intensity, and thus posing a serious threat to global food security. To meet the ever increasing food demand there is an urgent need to develop climate resilient maize varieties and the goal can be achieved by exploiting the pertinent physiological, biochemical and molecular mechanisms. Although some of the chilean landraces have been evaluated for some traits during the past decades, knowledge of molecular variation, diversity, genetic architecture, and selection that may underlie the phenotypic variation in the maize genome based on the entire chilean maize collection is unknown. The distribution patterns of adaative traits might be the result of ecological and evolutionary factors, including, environmental factors, natural selection and local selection pressures such as interaction with humans. Heat tolerance traits are more likely to be influenced by natural selection and thus have a restricted distribution. These traits distribution patterns are not random and could be geographically and spatially structured (Hakes and Cronin, 20). So, it is feasible to hypothesize that for heat tolerance, Chilean maize landraces genetic diversity is structured mostly according to the interaction of latitude and altitude that the Chilean landscape offers. Genomic footprints of this adaation should be better detected if environmental parameters (e.g. temperature) describing plant germplasm collection sites are used as selection criteria to focus on a subset of accessions that potentially harbor phenotypic variation for heat stress tolerance.
