Agronomic, Morphological, and Nutritional Characterization of Greek Traditional Pepper (Capsicum annuum L.) Landraces at Commercial and Physiological Maturity for Sustainable and Climate-Smart Vegetable Systems

Climate change poses a significant threat to agricultural productivity, particularly in low-input systems where resilient cultivars are crucial. Traditional pepper (<i>Capsicum annuum</i> L.) landraces represent a valuable genetic reservoir for adaptation, yet their agronomic and nutritional potential remains underexplored. In this study, twenty-five Greek pepper landraces and commercial varieties were comprehensively evaluated for morphological traits, early and total yield characteristics, and key fruit quality parameters. The results revealed substantial phenotypic diversity in both vegetative and reproductive traits, as well as considerable variation in fruit nutritional composition across the tested genotypes. Notably, 'Skopos', 'Mesoropi', and 'Lygaria' demonstrated superior yield performance, while 'Pogoniou', 'Lyra', and 'Kantanou' excelled in several nutritional quality traits, including high phenolic content, vitamin C, and antioxidant capacity. Heatmap analysis further identified 'Pogoniou', 'Filuria', 'Lyra', 'Lagada', and 'Lygaria' as consistently ranking among the top performers across yield and quality traits. These findings highlight the dual agronomic and nutritional value of traditional pepper landraces, underscoring their importance as a genetic resource for breeding programs. Overall, the study highlights the importance of conserving and utilizing local pepper germplasm as a sustainable approach to improve productivity, nutritional quality, and resilience in the face of climate change and low-input cultivation systems.