Abstract:

Aims: The tribe Triticeae (Poaceae) is a vital repository of wild crop relatives and forage germplasm, with irreplaceable value in agriculture, pastoralism, and ecological conservation. China boasts rich diversity of wild Triticeae taxa. However, the 5 genera and 12 species of Triticeae plants listed in the National Key Protected Wild Plants List (2021) generally suffer from insufficient basic data and difficulties in species identification, which severely restrict their conservation and utilization. This study aims to improve the basic dataset of these nationally protected Triticeae species and provide scientific support for their conservation and sustainable utilization. 

Methods: This study integrated curated herbarium specimen reviews and systematic field surveys to comprehensively analyze key traits of the target taxa, including morphological diagnostic features, geographical distribution, chromosome karyotype, and subgenomic composition. Meanwhile, molecular datasets were constructed to support accurate species identification based on subgenomic signatures and DNA sequence polymorphisms. The threatened categories of each species was re-assessed in accordance with the International Union for Conservation of Nature (IUCN) Red List Categories and Criteria, combined with quantitative data on population size, threat severity, and distribution range. 

Results: Our study clarified the morphological profiles and distribution characteristics of the 12 national key protected wild plants of the Triticeae. We obtained chromosome numbers and karyotypes for 10 species across 4 genera through cytological experiments. We successfully identified the subgenomic composition of 10 species via alignment coverage analysis of whole-genome resequencing data. Our k-mer-based phylogenetic analysis proved effective for molecular identification, while plastid genome “super-barcodes” showed poor resolution between different subgenomes. Studies on reproductive and dispersal capacity showed that species with large and heavy seeds have weak dispersal ability, narrow distribution ranges, and higher extinction risk. After reassessment according to IUCN criteria, the threat status of 10 species was upgraded (e.g. Agropyron mongolicum), 1 was downgraded (Psathyrostachys huashanica), and 1 remained unchanged (Elymus villifer), among which Hordeum innermongolicum was upgraded to Critically Endangered (CR) and was suspected to be extinct in the wild; habitat degradation and fragmentation caused by overgrazing were identified as the main threat factors. We finally proposed conservation recommendations, including implementing differentiated in situ protection management for each species, strengthening systematic collection and preservation of germplasm resources, and establishing a dynamic assessment and update mechanism for species in the National Key Protected Wild Plants List (2021). 

Conclusion: Through the integration of multidisciplinary data, this study clarified the taxonomic basis of national key protected wild plants of the Triticeae, revealed the intrinsic relationship between species adaptability and distribution patterns, and assessed their actual threatened status. These results provide core scientific evidence for formulating evidence-based conservation actions. Facing the dual demands of agricultural sustainable development and biodiversity conservation, the research, conservation, and rational utilization of this important wild genetic resource bank require sustained scientific investment and cross-sectoral collaborative management.

Key words: Triticeae, national key protected wild plants, geographical distribution, subgenome, chromosome karyotype, threatened categories assessment