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ABSTRACT: Agronomy is concerned with identifying practical solutions to agricultural constraints. Often this involves subjecting a range of genotypes to particular treatments, selecting the best combinations and moving on. The problem with this focused approach is that the results pertain to the specific (ie a subset of genotypes and environments), rather than the general (representative of the crop and target environment as a whole), and as result it can be difficult to apply the knowledge widely. Agronomic interventions usually aim to change the crop environment to improve productivity. An understanding of crop evolution to specific environments is a good starting point for this type of research. This is illustrated by the case of chickpea as an Australian cool season grain legume.

In Australia chickpea is grown as winter-annual and is subject to biotic (Ascochyta blight) and abiotic stresses (cold and subsequent terminal drought) which reduce yield and yield stability. Early phenology is required to avoid terminal drought and heat stress throughout most Australian cool-season environments. However, early flowering exposes chickpea to temperatures too low to set pods, resulting in unproductive cycles of flowering and subsequent abortion. Chilling tolerance is rare in chickpea because of its early evolution as a spring-sown Mediterranean crop, and subsequent dissemination to warm-winter environments in South Asia and East Africa. However, climatic analysis of global chickpea environments has demonstrated the diversity of habitats in which the crop is grown, and will be used to evaluate chilling tolerance in germplasm from areas with low temperatures during flowering. An alternative approach is to evaluate the wild relatives which have maintained a Mediterranean winter-annual lifecycle. Preliminary results show improved chilling tolerance in lines of Cicer judaicum and C. pinnatifidum, neither of which can be crossed with chickpea at present. More collection of wild relatives in the primary genepool of chickpea is required to advance this work because there are <30 original accessions of C. reticulatum (n=18) and C. echinospermum (n=10) in the world collection.