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ARS Home » Northeast Area » Frederick, Maryland » Foreign Disease-Weed Science Research » Research » Publications at this Location » Publication #416383
Research Project: Integrative Genomic and Biological Approaches to Detect and Manage Emerging Foreign Fungal and Oomycete Plant Pathogens

Location: Foreign Disease-Weed Science Research

Title: Virulence and genotypic diversity of the wheat stem rust pathogen (Puccinia graminis f. sp. tritici) detected in Jordan

Author
item ALANANBEH, KHOLOUD - University Of Jordan
item OLIVERA, PABLO - University Of Minnesota
item AL-ABDALLAT, AYED - University Of Jordan
item TAHAT, MONTHER - University Of Jordan
item Luster, Douglas
item Jin, Yue
item SZABO, LES - University Of Minnesota

Submitted to: Plant Pathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/17/2025
Publication Date: N/A
Citation: N/A

Interpretive Summary: Wheat stem rust (WSR) is an important disease of wheat and other cereal crops. Although WSR has been commonly observed and studied in the Middle East, the last reports in Jordan date from the late 1980s. The objectives of this research were to conduct a national survey of WSR in Jordan. A total of 152 samples from were collected from 49 fields, then tested for host response and DNA fingerprints. This report represents the first national survey of WSR in Jordan in over 30 years. The identification of genetic variants will streamline development of resistant wheat in breeding programs. Future work will continue surveying wheat-growing regions in Jordan, contributing to global WSR surveillance and breeding efforts.

Technical Abstract: Wheat stem rust (WSR), caused by Puccinia graminis f. sp. tritici (Pgt), is an important disease of wheat and other cereal crops. Although WSR has been commonly observed and studied in the Middle East, the last reports in Jordan date from the late 1980s. The objectives of this research were to conduct a national survey of WSR in Jordan and assess the race composition and genotypic diversity of the Pgt population. A total of 78 WSR live samples and 74 dead samples from 49 fields were collected in 2018. In addition, three historical samples were analyzed. One hundred Pgt isolates derived from the live samples were race-typed and 14 representatives of the identified races were SNP genotyped; while the dead and the historical Pgt samples were all SNP genotyped. Five races were identified from the live isolates: PKTTF, TKFTF, TKFTP, TKKTF, and TTRTF. The most frequent race was TKKTF (75%) followed by TKFTF (14%), and TTRTF (9%), whereas races PKTTF and TKFTP were detected from only one isolate. Selected Pgt isolates representing the five races identified were differentiated into five genetic clades/sub-clades: III-B, race TTRTF; IV-C, race PKTTF; IV-E.1, race TKFTP; IV-E.2, race TKKTF; and IV-F, race TKFTF. Using SNP markers, the dead samples were genotyped as clades: IV-E.2 (73.7%), III-B (18.4%), and III-B, IV-F, and Co-A22 at frequencies less than 4%. Minor allelic variations at one or two SNP loci were observed among the dead samples. The dead sample genotyped as Co-A22 was identical to European reference isolates from the early 1980s. From the 36 single uredinial pustules derived from the historical samples, two genotypes were detected: clade III-A and, Co-A22. The northern governorate of Irbid exhibited the highest level of Pgt diversity. Future work will continue surveying wheat-growing regions in Jordan to detect and monitor Pgt races, contributing to global WSR surveillance efforts.