Strawberry genotypes with resistance to Tetranychus urticae mediated by leaf trichomes

Abstract

The two-spotted spider mite (Tetranychus urticae) is the main pest encountered in strawberry cultivation in protected environments, causing damage and increasing the cost of production associated with chemical control. Breeding programs are essential for obtaining new cultivars that are more tolerant to two-spotted spider mites. The objective was to evaluate whether the leaf trichomes mediatethe resistance of intraspecific strawberry hybrids to two-spotted spider mites. Preselected hybrids were subjected to infestation by two-spotted spider mites and evaluated via the no-choice assay and the travel test. Resistance was correlated with the density of trichomes, both glandular and non-glandular, present on the surface of the leaflets of strawberry genotypes. The results indicated that there is an influence of hybrids and cultivars on the behavior of the pest, allowing the verification of the existence of resistant genotypes (RVDA#16, RVCS#44 and Camino Real). These treatments resulted in low numbers of eggs deposited and hatched compared with the other treatments and shorter distances traveled by two-spotted spider mites on the surface of leaflets. It was also verified that the glandular trichomes presented a significant negative correlation with the average distance traveled by two-spotted spider mites on the surface of the leaf discs, indicating that these structures alter the behavior of these arthropods. Genotype resistance was associated with the presence of glandular trichomes. In addition to the superiority of the agronomic and postharvest attributes of the preselected hybrids (RVDA#16 and RVCS#44) identified in the previous selection efforts, they proved to be promising materials for achieving resistance to the spider mite, revealing important genotypes for use as cultivars and particularly as parents in breeding programs.

Relationship between salicylic acid and resistance to mite in strawberry

“…The influence of the strawberry foliar glandular and non-glandular trichomes on the resistance to TSSM was suggested by other researchers (Figueiredo et al, 2013;Kumari et al, 2018;Resende et al, 2020). Non-glandular trichomes function as a system of mechanical defence, diminishing oviposition, feeding and locomotion (Krimmel, 2014;Riddick and Simons, 2014), whereas glandular trichomes secrete and release defensive secondary metabolites such as terpenes, alkaloids and phenols (Delgoda and Murray, 2017;Tian et al, 2017).…”

“…The sesquiterpenes Zingiberene, present in some tomato glandular trichomes, was associated with TSSM nymph mortality and diminishing fecundity (Oliveira et al, 2018;Oliveira et al, 2020). The strong correlation observed between the density of non-glandular trichomes and the oviposition and survival of adults are presumably related to the dysfunction caused by these structures to the movement and permanence of the mite on the surface of the leaflet (Resende et al, 2020).…”

Plant Responses to Herbivory, Wounding, and Infection

“…High trichome density further increases plant resistance against attacks. For example, strawberry plant resistance to the two-spotted spider mite (Tetranychus urticae) was increased at higher trichome densities [18]. Both the physical structure of trichomes and their chemical constituents influence plant protection [19].…”

Avances en el cultivo de las berries en el trópico

“…Esto permite hipotetizar que la tolerancia varietal a T. urticae podría estar relacionada con la densidad de cuerpos ergásticos foliares (Neira et al, 2021). Otros estudios mantienen la hipótesis de que la tolerancia varietal en fresa está relacionada a la densidad de tricomas glandulares en los folíolos (Gugole Ottaviano et al, 2013;Resende et al, 2020). Estas características podrían ser la base para la obtención de cultivares de fresa tolerantes a la araña roja.…”