Determination of Color and Heat Level of Some Resistance Sources and Improved Pepper Genotypes

Abstract

Background: In this study, the capsaicin content, heat level and color of nine pepper genotypes and varieties belonging to Capsicum annuum and Capsicum chinense were described at different ripening stages. Heat level and color is a desirable feature for Turkish pepper consumers. Therefore, knowledge on the heat level and of Turkish pepper genotypes is important for a future breeding project aiming variety development. Methods: Turkish materials (Alata 10, 15 and 111) were improved from the pepper collection of Alata Horticultural Research Institute-Turkey. The Rwandan variety Pili-Pili is consumed in Rwandan cuisine. The capsaicin content of the Alata collection and Pili-Pili were identified both at immature and red ripening stages. In addition, some accessions carrying various resistances to diseases were evaluated: namely Er-Fu-Tou (Cucumber Mosaic Virus), C29 (Phytophthora capsici and Potato Virus Y), PI 260429 (Tobacco Mosaic Virus) and PI 152225 (Tomato spotted wilt virus); for these accessions, sampling was done at red ripening stage. High-performance liquid chromatography (HPLC) was used for identifying capsaicinoids and extraction was performed by sodium acetate saturated ethanol. ASTA 20.0 method was applied to measure the extractable color of improved lines. Results: •Results demonstrated that there was considerable variation among genotypes. •The highest capsaicin content and heat level were detected in the genotype PI 152225. For dihydrocapsaicin content, Er-Fu-Tou variety was the first and followed by PI 260429 and PI 152225. •Heat level in pepper involves the relationship between capsaicin and dihydrocapsaicin and therefore, it is important to convert to the Scoville Heat Unit (SHU). The most pungent genotype PI 152225 was followed by Pili-Pili variety (red stage), Er-Fu-Tou, Rwandan Pili-Pili variety (immature stage), Alata 111 (red stage) and PI 260429. •The highest ASTA value was detected in mature fruits of Er-Fu-Tou genotype with 217 ASTA color value and it was followed by improved line Alata 111 from Kahramanmaras pepper population with 173 ASTA. Conclusions: At the end of study, Er-Fu-Tou (CMV resistant) and PI 152225 (TSWV resistant) lines were found to be useful to improve varieties having both quality properties and resistance to diseases from the Kahramanmaras red pepper population via short term breeding program while they were not suitable to improve sweet pepper with rapid breeding program. Rwandan variety Pili-Pili was not found appropriate to improve varieties producing high quality dried pepper.