Paprika (Capsicum annuum) cannot grow or set fruit in temperatures that are higher than the optimal level. This study assesses the characteristics of 52 paprika accessions introduced from the agrobiodiversity center and the world vegetable center during a high temperature period in order to develop heat tolerant lines. As a result of controlling the temperature in two greenhouses by side ventilation and fogging system, the average daily temperature of the high temperature regime was 34.3℃, which was 2.4℃ higher than that of the normal temperature regime. Plant height, stem diameter, fruit set, fruit weight, fruit shape, pericarp thickness, soluble sugar content, yield, and marketable fruit development rate were all investigated as vegetative and reproductive growth-related parameters. Plant height, fruit weight, pericarp thickness, and yield were all reduced during high temperature treatment. Six germplasm lines (T12, T15, T26, T29, T32, and T36) were selected as high-temperature tolerant lines based on these parameters. The selected lines will be used to breed heat-tolerant cultivars as well as crossbreeding for genetic analysis.

Watermelons are grafted to prevent soil-borne diseases such as Fusarium wilt (FW) and increase their resistance to abiotic stress. Root-knot nematodes (RKN) are a contributing factor to economic loss in several cucurbits, including watermelon. Growing resistance varieties is an effective way to reduce the damage caused by soil-borne diseases. Resistance evaluation was performed on 50 watermelon lines to select rootstocks resistant to FW and RKN. Fusarium oxysporum f. sp. niveum race 2 was inoculated into 10-day-old seedlings using a root dipping method, and resistance was evaluated for four weeks. The 37-day-old watermelon seedlings were inoculated with Meloidogyne incognita and evaluated 60 days later. Three lines (IT199860, PI296341-6, and PI532811) were resistant to FW race 2, while one line (PI494527) was moderately resistant. Three lines (PI296341-5, PI457916-2, and PI457916-5) were RKN resistant. The PI296341-6 line was selected for its resistance to FW and moderate resistance to RKN. These findings imply that the identified resistant lines can be used in rootstock breeding programs against FW and/or RKN.