Current research status and emerging trends in wheat: An integrated scientometric analysis based on ploidy uncovers hidden footprints in the scientific landscape

Wheat, a highly versatile staple crop cultivated extensively for its grains on a global scale, is poised to experience increased demand to sustain the burgeoning population, owing to its superior nutritional potential. Modern wheat, a hexaploid species, has evolved through the introgression of numerous preceding ploidies, including Einkorn, Emmer, Aegilops, and others, each possessing distinct qualitative and quantitative traits. Scientometric and topical analyses serve as effective tools to quantitatively evaluate scientific research by measuring the knowledge expressed in scientific publications and keywords. Thus, comprehending the research status regarding wheat domestication events within primary, secondary, and tertiary gene pools is paramount for enhancing wheat production. In this study, we analyze data retrieved from PubMed to elucidate the research status and identify bottlenecks across different ploidy of genomic pools of wheat. The publication trends on wheat have experienced exponential growth over the past three decades, with China emerging as a leading center for publications. In contrast to the publication frequency observed in hexaploid common wheat, scholarly output concerning Einkorn and Aegilops is approximately tenfold lesser, with emmer trailing behind at three times fewer publications. This discrepancy underscores the prioritization of expedited research initiatives targeting these species, aimed at elucidating latent biological characteristics and optimizing their breeding capabilities. Keywords such as "stress," "GWAS," and "gene" are prominent, reflecting the challenges posed by climatic factors on wheat production and their mitigation through molecular breeding and gene manipulation. Notably, the keyword "einkorn" highlights its potential as a donor for fine-tuning traits related to wheat adaptation processes and quality, crucial for modern wheat's survivability under adverse climates. Conversely, higher publication rates on emmer are primarily associated with Italy, possibly due to its favorable Mediterranean climate for tetraploid wheat. Keywords like "Pasta" and "Ochratoxin, DON" are prevalent, with the former being derived from durum wheat and the latter being reported in higher amounts in durum compared to other wheat species, rendering it less suitable for consumption. Enriched keywords such as "genome" and "resistance" underscore the critical characteristics of Aegilops. Other significant keywords like "Aceria tosichella" possibly indicate multiple stages of resistance conferred by Aegilops, while the presence of the grain softness protein "puroindoline" enhances its acceptability for donation by Aegilops. Spelt, a close relative of common wheat, exhibits a research trend with thousands of annual publications and enriched keywords such as "stress" and "yield" reflect the current scientific emphasis on wheat research. Furthermore, hierarchical keywords like "bio-control" and "celiac disease" merit consideration for future research on hexaploid wheat.