*mpsilva@inia.org.uy

Triticum monococcum (2n = 2x = 14, AmAm), commonly known as einkorn wheat, represents a reservoir of untapped genetic diversity with promising implications for enhancing wheat breeding aimed at bolstering resistance to pests and diseases. Among these threats, the wheat curl mite poses a significant challenge to wheat production, primarily through its role as a vector for various viral diseases, including wheat streak mosaic virus.

While only five resistance genes against the curl mite have been identified thus far, notably, three of these genes were sourced from a wild relative species of wheat. Given the absence of widespread genetic resistance within wheat germplasm, our study explored the genetic architecture of curl mite resistance within T. monococcum. We tested 214 accessions, comprising 159 from T. monococcum subsp. aegilopoides and 55 from subsp. monococcum.

Under controlled conditions, accessions were infested with Aceria tosichella biotypes 1 and 2. Curl mite symptoms were recorded at the two-leaf stage, utilizing a 0-4 visual scale, where 0 denoted no symptoms (indicative of resistance), while scores ranging from 1 to 4 reflected increasing degrees of curliness or leaf entrapment (indicative of susceptibility).

Phenotypic assessment revealed the presence of both resistant and susceptible accessions within both T. monococcum subspecies, with a broad spectrum of phenotypic variability observed across the entire accession set. Notably, a greater proportion of accessions exhibited susceptibility compared to those displaying resistance, with biotype 1 demonstrating heightened aggressiveness relative to biotype 2. Mean phenotypic values for subsp. aegilopoides were 1.52 and 0.96 for biotypes 1 and 2, respectively, while for subsp. monococcum, mean values for biotypes 1 and 2 were 1.87 and 0.91, respectively.

Our findings highlight significant levels of resistance present within the tested T. monococcum accessions, underscoring the potential of this wild species as a reservoir of novel resistance against curl mite.

Ongoing association analyses, integrating phenotypic data with whole-genome sequencing data, aim to provide further insights. The findings of our study have broad implications for ongoing efforts in wheat breeding, aiming to create wheat varieties that are more resilient against the challenges presented by the wheat curl mite, thus advancing sustainable agricultural production.