Trichome and biochemical basis of resistance against Tuta absoluta in tomato genotypes

Abstract

South American tomato moth, Tuta absoluta, a serious pest of tomato (Solanum lycopersicum) in tropics and subtropics, is rapidly spreading world over. Twenty one wild/cultivated/advanced breeding lines of tomato were screened for resistance to T. absoluta under greenhouse conditions (choice bioassay) and promising genotypes were evaluated further for their antibiosis activity through no choice bioassay under in-vitro conditions. From 21 genotypes screened, six wild accessions viz., S. pennellii (LA 1940); S. chilense (LA 1963); S. arcanum (LA 2157); S. lycopersicum (LA1257) and S. corneliomulleri (LA 1292, LA1274) were relatively resistant to T. absoluta based on mean percent damage and were further studied under in-vitro conditions. These genotypes recorded relatively more larval mortality, prolonged larval and pupal duration with reduced adult emergence of T. absoluta. Among these six genotypes, S. pennellii (LA-1940) showed resistance both under choice and no choice bioassays with higher number of type IV trichomes, highest total flavonoids and phenols. In general, glandular trichomes (GTs) (type I, IV, VII) showed negative correlation in different genotypes of tomato with reference to larval number/plant, percent damage and adult activity, whereas type V (non-GTs) showed negative correlation with number of larvae/plant.

Population parameters of the tomato leaf miner Tuta absoluta (Lepidoptera: Gelechiidae) on wild tomato species

“…As a result of the present study, the response of the pest in all the developmental stages may change depending on the host plants. A similar result was found in a recent study (Sridhar et al 2019a) reporting that S. corneliomulleri was resistant to T. absoluta. Nevertheless, we are unable to compare our life table results with the previous study of Sridhar et al (2019a) because they did not include these parameters.…”

TheLanatatrichome mutation increases stomatal conductance and reduces leaf temperature in tomato

“…We found that the Ln mutation increased assimilation rate and stomatal conductance, while reducing leaf temperature. Given the growing interest in altering trichome density in tomato and other crops to increase insect resistance (Glas et al , 2012), and to exploit the production of secondary metabolites (Sridhar et al , 2019), we discuss the physiological and breeding implications of our results.…”

Screening of Elite Genotypes of Tomato against Major TOSPO Vector- Thrips Complex

“…High glandular trichome density has shown resistance to other sucking pest like white flies, Tetranychus mite and also lepidopteran pests like T.absoluta (Rakha et al, 2017, Sridhar et al, 2019. Our field as well as lab studies shows high resistance of thrips population in case of S. galapagense (VI037241) and S. cheesmaniae (VI037240) which can be used as a resistant source for future breeding lines.…”