|Abdel Moniem, Hossam - Purdue University|
|Flanders, Kathy - Purdue University|
|Buntin, G - University Of Georgia|
|Subramanyam, Shubha - Purdue University|
Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/30/2016
Publication Date: 5/17/2017
Citation: Johnson, A.J., Abdel Moniem, H.E., Flanders, K.L., Buntin, G.D., Subramanyam, S., Shukle, R.H., Schemerhorn, B.J. 2017. A novel, economical way to assess virulence in field populations of Hessian fly (Diptera: Cecidomyiidae) utilizing H13 as a model. Journal of Economic Entomology. 110(4): 1863–1868. https://doi.org/10.1093/jee/tox129.
Interpretive Summary: Hessian fly is one of the most damaging insect pests to wheat across the world. One of the major problems in the control of Hessian fly is its ability to rapidly overcome resistance genes in wheat. Identifying what resistance genes a Hessian fly population is virulent to is traditionally a time consuming effort. It historically requires live fly caught from a given area and subsequently screening that fly against wheat containing the 25 described resistance genes. In this report, we describe a new way of screening for virulence in a Hf population that rapidly shortens the screening time and the results correspond to the traditional screening results proving it to be an effective means of screening for virulence in fly populations throughout the US.
Technical Abstract: Mayetiola destructor (Say) is a serious pest of wheat in the southeastern United States. The Hessian fly (Hf) uses effector triggered immunity to overcome wheat’s H genes, the resistance genes responsible for providing protection from the Hf. As the most effective form of Hf control employs the planting of resistant wheat cultivars containing one or more H genes, frequent Hf sampling is required to monitor the level of virulence present in locally adapted populations. Here, we present a novel assay for detecting virulence in the field. Hf males were collected in Alabama, North Carolina, and South Carolina using sticky traps baited with Hf sex pheromone. The Hf gene that controls virulence in Hf to resistance gene H13 in wheat has recently been cloned and characterized, and diagnostic molecular markers for the alleles controlling avirulence and virulence are now available. Utilizing two separate PCR reactions, the six alleles for avirulence and virulence can be scored based on band size. Our results support the most recent survey of virulence to H13 as scored through the testing of live insects infesting H13 wheat in the greenhouse. Throughout the southeast, all three avirulence alleles can be identified while the most frequently identified allele for virulence corresponded to a 5kb insertion into exon 1 of vH13. In South Carolina, the PCR assay detected low levels of virulence to H13 despite greenhouse screenings indicating no virulence in these populations.