These descriptors are being used by the Breeding Unit and the Genetic Resources and Seed Unit (GRSU) of WorldVeg to screen for biotic stress in genebank accessions of tomato and its wild relatives. These descriptors have been published by Mohamed Rakha et al. (2017a;b Genetic Resources and Crop Evolution; https://doi.org/10.1007/s10722-015-0347-y; https://doi.org/10.1007/s10722-016-0421-0).
Rakha M, Bouba N, Ramasamy S, Regnard JL, Hanson P (2017) Evaluation of wild tomato accessions (Solanum spp.) for resistance to two-spotted spider mite (Tetranychus urticae Koch) based on trichome type and acylsugar content. Genetic Resources and Crop Evolution, 64(5), 1011-1022. DOI: 10.1007/s10722-016-0421-0.
The taxa of the pest.
There are two types of bioassay: choice and no choice.
| Code | Term | Description |
|---|---|---|
| 12 | choice |
Count of eggs 15 days after infestation.
Count of nymphs 15 days after infestation.
Count of pupae 15 days after infestation.
Count of adults 3 days after infestation.
Count of adults 19 days after infestation.
Count of number of trichome type I in a square millimeter. Determined from the interior middle section of the abaxial surface of the third leaf from the apex.
Count of number of trichome type IV in a square millimeter. Determined from the interior middle section of the abaxial surface of the third leaf from the apex.
Count of number of trichome type V in a square millimeter. Determined from the interior middle section of the abaxial surface of the third leaf from the apex.
Count of number of trichome type VI in a square millimeter. Determined from the interior middle section of the abaxial surface of the third leaf from the apex.
Count of number of trichome type I in a square millimeter. Determined from the interior middle section of the adaxial surface of the third leaf from the apex.
Count of number of trichome type IV in a square millimeter. Determined from the interior middle section of the adaxial surface of the third leaf from the apex.
Count of number of trichome type V in a square millimeter. Determined from the interior middle section of the adaxial surface of the third leaf from the apex.
Count of number of trichome type VI in a square millimeter. Determined from the interior middle section of the adaxial surface of the third leaf from the apex.
Percentage of adult mortality.
Count of eggs from 1 female after two days infestation.
The leaf damage 5 days after infestation.
Legend:
No damage
Few small feeding patches (<20 % of leaf area)
Large feeding patches 20–49 % of leaf area
Entire leaf with feeding marks (>=50 % of leaf area)
Count of eggs from 10 females two days after infestation. Determined from the interior middle section of the abaxial surface of the third leaf from the apex.
Count of eggs from 10 females two days after infestation. Determined from the interior middle section of the adaxial surface of the third leaf from the apex.