Search

Hessian fly (HF) (Mayetiola destructor Say) is an obligate destructive pest of wheat (Triticum aestivum L.) causing severe economic losses worldwide. Deployment of resistant wheat cultivars harboring 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 HF 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, we evaluated the phenotypic response of 254 Triticum turgidum (L.) wheat accessions of African origin to Biotype L HF infestation. Of these, 10 accessions exhibited >70% resistance to Biotype L HF infestation. These 10 resistant accessions also showed >70% resistance when screened with vH13 HF biotype. Additionally, these HF resistant lines were evaluated for expression of resistance at a higher temperature of 30°C, and three tetraploid wheat accessions that maintained 100% resistance to Biotype L HF at the increased temperature were identified. These newly identified HF resistant lines 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. Core Ideas: Triticum turgidum wheat accessions were phenotyped to identify new sources of resistance to Hessian fly. Identified 10 and 12 new sources of resistance in wheat to Biotype L and vH13 Hessian fly, respectively. Three of the tetraploid wheat lines maintain Hessian fly resistance at higher temperatures. [ABSTRACT FROM AUTHOR]

Summary: Large structural variations frequently occur in higher plants; however, the impact of such variations on plant diversification, adaptation and domestication remains elusive.Here, we mapped and characterised a reciprocal chromosomal translocation in soybeans and assessed its effects on diversification and adaptation of wild (Glycine soja) and semiwild (Glycine gracilis) soybeans, and domestication of cultivated soybean (Glycine max), by tracing the distribution of the translocation in the USDA Soybean Germplasm Collection and population genetics analysis.We demonstrate that the translocation occurred through CACTA transposon‐mediated chromosomal breakage in wild soybean c. 0.34 Ma and is responsible for semisterility in translocation heterozygotes and reduces their reproductive fitness. The translocation has differentiated Continental (i.e. China and Russia) populations from Maritime (i.e. Korea and Japan) populations of G. soja and predominately adapted to cold and dry climates. Further analysis revealed that the divergence of G. max from G. soja predates the translocation event and that G. gracilis is an evolutionary intermediate between G. soja and G. max.Our results highlight the effects of a chromosome rearrangement on the processes leading to plant divergence and adaptation, and provides evidence that suggests G. gracilis, rather than G. soja, as the ancestor of cultivated soybean. [ABSTRACT FROM AUTHOR]