Triticeae Genomics and Genetics, 2024, Vol.15, No.4, 173-184 http://cropscipublisher.com/index.php/tgg 174 techniques, including molecular biology and genomic selection, holds promise for addressing future agricultural challenges. These advancements can enhance traits such as disease resistance, drought tolerance, and nutrient use efficiency, ensuring sustainable crop production in the face of climate change (Ayalew et al., 2018; Maeda and Nakamichi, 2022). This study synthesizes current knowledge on the spread and adaptation of Triticeae crops from their ancient origins to their present-day global distribution. By examining historical records, genetic studies, and modern breeding efforts, it provides a comprehensive understanding of the factors that have shaped the success of Triticeae crops. Understanding the genetic and environmental mechanisms underlying the adaptation of Triticeae crops is crucial for future crop improvement strategies. This knowledge can inform breeding programs aimed at developing resilient crop varieties capable of thriving in diverse and changing environments. This study highlights the significance of Triticeae crops in global agriculture and their potential contribution to food security and sustainable agricultural practices in the future. 2 Historical Origins and Domestication 2.1 Early evolution and wild relatives The early evolution of Triticeae crops is deeply rooted in the Fertile Crescent, a region that spans modern-day Israel, Jordan, Lebanon, western Syria, southeastern Turkey, and parts of Iraq and Iran. This area is recognized as the cradle of Western agriculture, where wild progenitors of modern cereal species, such as wild wheats (Triticum urartu, T. boeoticum, T. dicoccoides), wild barley (Hordeum spontaneum), and wild rye (S. vavilovii), naturally intersect. The presence of these wild species in early archaeological sites, followed by domesticated forms, provides substantial evidence for the region's role in the advent of agriculture (Ozkan et al., 2002). Molecular evolutionary studies have further elucidated the origins of these crops. Techniques such as amplified fragment length polymorphism (AFLP) have been instrumental in identifying the specific natural stands from which wild crops were domesticated. For instance, AFLP analysis has pinpointed the Karacadag Mountains in southeastern Turkey as the site of einkorn wheat domestication, supported by genetic similarities between wild and domesticated populations. This genetic evidence is complemented by archaeobotanical remains from early settlements in the region, reinforcing the significance of the Fertile Crescent in the early evolution of Triticeae crops (Ozkan et al., 2002). 2.2 Domestication process and regions The domestication of Triticeae crops, including wheat and barley, marked a pivotal transition from hunting and gathering to agriculture, significantly impacting human societies. Wild emmer wheat (Triticumdicoccoides) was among the first cereals to be domesticated in the Fertile Crescent around 12 000 to 10 000 years ago, laying the foundation for subsequent bread wheat evolution. The geographic distribution of wild emmer today spans the western Fertile Crescent, including Jordan, Syria, Israel, southeastern Turkey, and parts of Iraq and Iran, indicating the broad region involved in its domestication (Özkan et al., 2010). The domestication process of tetraploid wheats appears to have been multiregional. Genotyping-by-sequencing (GBS) studies have shown that domesticated tetraploid wheats have genetic affinities with wild emmers from both the northern Fertile Crescent and the southern Levant. This suggests a complex domestication scenario involving admixture and allele sharing between domesticated and wild populations from different regions. Archaeological evidence supports the initial cultivation of tetraploid wheats in the southern Levant, followed by their spread and mixing with wild populations in southeastern Turkey, leading to the fixation of domestication traits (Oliveira et al., 2020). 2.3 Genetic changes during domestication The domestication of Triticeae crops involved significant genetic changes that enhanced their suitability for agriculture. One of the key outcomes of domestication was the increase in yield, driven by traits such as larger seed size, greater plant size, and reduced chaff or pod material. These changes resulted in domesticated cereals and pulses having, on average, 50% higher yields than their wild progenitors. The increase in seed mass and
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