Evaluation of host plant resistance against leafhopper, Amrasca biguttula Ishida, (Hemiptera: Civadellidae) among cultivated and crop wild relatives of eggplant (Solanum melongena L.) using conventional and high throughput phenotyping methods)

Evaluation of resistance of cultivated eggplant and wild related species against leafhopper (LH) was compared using conventional standard and digital high throughput phenotyping methods by weekly monitoring the density/plant from 4-6 weeks after transplanting (WAT) and conducting visual damage assessment. LH damage on yield was also measured starting at 7-10WAT. Significant differential reaction was found among the 30 genotypes with PH9405 (Solanum mammosum L.), a crop wild relative (CWR) with the lowest mean LH count (0.0 LH/leaf) and GB56163 with the highest mean count (16.2/leaf). LH counts among cultivated eggplants ranges from 3.7-16.2/leaf. Parallel visual damage assessments showed significant reactions to LH damage among the genotypes. Fruit yield revealed that PHL 9405 had tje mean highest fruit yield (22.4 fruits/plant) and JP33351 had the least mean number (0.1 fruits/plant). Entry PH0014 with 10.8 mean fruits/plant showed tolerance with 10.9 LH count. Percentage hopperburn leaf injury was measured using Compu Eye digital software. Entry, PHL 9405 had the lowest incidence of hopperburn (5.7%) while JP33351 had the highest (50.6%). Percentage hopperburn leaf damage for the other genotypes ranged from 15.8-36.6%. Based on the four parameters, 10 genotypes were evaluated for the caged feeding and ovipositional preference tests based on number of LH adults that alighted 5-7 days after release and number of newly emerged nymphs, respectively. Results showed that JP33351 was most preferred with mean 11.9 adults/plant and PHL9405was the least preferred with no adults alighted on the plant at all. Trichome characteristics was examined among genotypes. There wer grandular and non-grandular trichomes. Type 7 grandular ans stellate non-grandular trichomes was present among the cultivated eggplants and CWRs. entry PHL 9405 has types 4, 6, and 7 glandular trichomes and types 2, 3, and 5 non grandular trichomes. The length and density of trichome is negatively correlated to the density of LH/plant. An EntoLab sup TM digital high phenotyping platform was tested in an no-choice test through tracking LH to investigate the feeding behaviour among the 10 genotypes. Out of the 37 behavior parameters measured, 27 of them showed significant differences among genotypes. From these screening methodologies, results suggested that detailed insect behavior can be discriminated using EntoLab TM for sucking insect such as LH. The platform was robust, precise and results can be generated in such as short time. The entries with insect resistance together with the genotype data are useful in genome-a wide association studies for crop breeding works. The conventional screening method on the other hand is very tedious, erratic and need two seasons relying on high number of test insects.