Resistance of strawberry genotypes to the two-spotted spider mite, Tetranychus urticae (Acari: Tetranychidae)

Abstract

Cultivating resistant genotypes can be an efficient method for keeping mite populations below levels that cause economic damage in crop plants because it is inexpensive and can be integrated with other pest control tactics. The present work evaluated the resistance of nine experimental strawberry genotypes (MCA89, MFA444, MCA93–01, MFA443–01, MFA451, MCA111, MOGSC468, MFA443, and MDA22) to the two-spotted spider mite Tetranychus urticae Koch compared to two commercial cultivars (Camarosa and Dover). Laboratory oviposition assays were performed using excised leaf discs. Although significant differences were observed in mite's oviposition, none of the strawberry genotypes stood out for high resistance levels. The lowest oviposition averages were found in the genotype MDA22 (abaxial 17.13 ± 4.20 and adaxial 30.63 ± 6.80), resulting from a cross between cv. Dover and cv. Aromas, genotypes considered to have intermediate resistance to T. urticae. In addition, MDA22, provided neutral stimulus for mite's oviposition on the abaxial and adaxial surfaces. Given the results, MDA22 genotype should be used as a parent for new crossings in breeding programs that aim to increase the genetic basis of genotypes adapted to Brazilian edaphoclimatic conditions and resistant to T. urticae.