Bottom-up effects of breeding tomato genotypes on behavioural responses and performance of Tetranychus evansi population

摘要

The tomato red spider mite, TRSM, Tetranychus evansi Baker & Pritchard (Acari: Tetranychidae), is an invasive tomato pest in several countries, with potential to reduce yield by up to 90% in Africa. Solanum habrochaites, access PI 134417 is a wild tomato genotype resistant to several arthropod pests, including TRSM. There is an interest in increasing the resistance of a tomato genotype (Solanum lycopersicum cv. TLCV15) widely cultivated by smallholder western African farmers to TRSM, through interspecific crossings with that wild genotype. For this purpose, after obtaining the F1 progeny and as well as F2 (SPJ-10-2017) and BC1 back-crossed (SPJ-05-2018) genotypes selected for high glandular trichome densities, we characterized their resistance level to TRSM. We quantified the types and densities of trichomes on the abaxial surface of their leaflets, and examined the subsequent bottom-up effects of these progeny plants attributes on behaviour and demographic parameters of the mite. Our results showed that the densities of glandular trichomes inherited from the resistant genotype (PI 134417) by the progenies were highly variable, with types I, IV and VI being the most prevalent. The progeny SPJ-10-2017 was classified as resistant, while the progenies F1 and SPJ-05-2018 were classified as partially resistant. These findings constitute one of the first steps towards advancing breeding programs in African countries to obtain tomato genotypes resistant to TRSM, targeting more sustainable production.