Af s micro nikkor 105 mm 1 2.8g ed lens

The morphology of at least five plants of each stsr4 mutant line was examined. Single nodes were cut from cultured potato plantlets and cultured in basal MS medium at 24°C, 16 h light/8 h dark photoperiod, and 50% humidity. All plants were photographed daily with a high-resolution camera (Nikon D750 with AF-S Micro Nikkor 105 mm 1:2.8G ED lens; Nikon, Inc., Japan) for up to 30 days. Phenotypic traits including number of branches per plant, number of leaves per branch, stem length, and midrip length were measured using four plants excluding maximum and minimum values from six plants with ImageJ software (https://imagej.nih.gov/ij). Midrip and petiole lengths were measured with an average of three leaves from the first leaf excluding the shoot-tip in each plant. However, the early stage phenotype (0 day-5days) was measured with an average of two leaves in each plant due to the small size plant.

To perform the P. infestans resistance assay, fully expanded leaves of stsr4 mutants (selected based on targeted deep sequencing data) and wild-type Desiree plants, grown in a controlled room at 25°C and 16 h light/8 h dark photoperiod, were inoculated with P. infestans strain 88069 zoospore suspension (3 × 10⁴ sporangia/mL), as described previously (Ha et al., 2017 (link)). The inoculated plants were incubated at 20°C under high humidity (95–100%), and disease symptoms were examined at 5 days after inoculation (DAI). Five days after inoculation, the area of necrotic symptoms to the total leaf area in the whole plant was investigated, and the average ratio (%) of symptom was quantified from high-resolution camera (Nikon D750 with AF-S Micro Nikkor 105 mm 1:2.8G ED lens; Nikon, Inc., Japan) and ImageJ software. All experiments were repeated five times.