Identification of new sources of Hessian fly resistance in tetraploid wheat.

Authors: Nemacheck, Jill; Flynn, Rachel; ZAPF, KATHLEEN - US Department Of Agriculture (USDA); Subramanyam, Subhashree

Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/19/2022
Publication Date: 1/20/2023
Citation: Nemacheck, J.A., Flynn, R.D., Zapf, K., Subramanyam, S. 2023. Identification of new sources of Hessian fly resistance in tetraploid wheat. Crop Science. 63(3):1354-1363. https://doi.org/10.1002/csc2.20917.
DOI: https://doi.org/10.1002/csc2.20917

Interpretive Summary: Insect pests pose a threat to global wheat production, a staple crop for an estimated 35% of the world population. Hessian fly (Hf) is one such insect pest resulting in significant yield reduction of wheat crop in both the United States and worldwide, causing losses of hundreds of millions of dollars annually. Planting resistant wheat cultivars is still the most effective and economical approach to manage this insect pest. However, extensive use of resistant cultivars puts enormous selection pressure on Hf populations, leading to the development of new insect biotypes that evolve to breakdown plant resistance. Hence, there is urgent need to continually identify new and novel sources of Hf resistance in wheat plants. In this study, we screened 254 wheat lines and found 10 lines exhibiting high levels of resistance to two Hf larval biotypes, that can be used in wheat breeding programs to develop cultivars for use by farmers to help alleviate insect damage. Additionally, three of these resistant wheat lines were able to withstand high temperatures whereas resistance in several other wheat lines breaks down or is seriously compromised. These temperature-independent Hf resistant wheat accessions can serve as potential candidates for use in geographical locations with higher environmental temperatures and still provide robust resistance to Hf.

Technical Abstract: Hessian fly (Mayetiola destructor Say) is an obligate destructive pest of wheat (Triticum aestivum L.) causing severe economic losses worldwide. Deployment of resistant wheat cultivars harboring Hessian fly (HF) resistance (H) genes is still the most effective and economical method to manage this insect pest. However, extensive use of H genes can impose selection pressure on Hessian fly populations, leading to the development of virulent biotypes that can breakdown plant resistance. Further, increase in environmental temperatures to 25-30'C during the wheat growing season can also negatively impact HF resistance, thereby necessitating the identification of new and novel sources of HF resistance and evaluate them for temperature sensitivity. In the current study, 254 Triticum turgidum (L.) (tetraploid) wheat accessions of African origin were evaluated to Biotype L HF larval attack and ten new accessions identified that exhibited >70% resistance. These accessions were also resistant to vH13 HF attack. Additionally, these HF resistant lines were evaluated for expression of resistance at a higher temperature of 30'C, and three tetraploid wheat accessions that were able to maintain 100% resistance to Biotype L HF at the increased temperature were found. These newly identified HF resistant cultivars offer valuable tools to breeders and farmers that can be used in breeding programs to develop cultivars for durable resistance to HF and efficient crop management.