Integrating Reproductive, Physiological, and Oil Quality Traits Identifies Promising Peanut (Arachis hypogaea L.) Germplasm for Crop Improvement

Peanut (Arachis hypogaea L.) is an important oilseed crop whose diversity provides opportunities to identify germplasm combining high yield, physiological performance, and desirable oil quality. This study evaluated the morphophysiological, productive, and biochemical diversity of ten peanut accessions under field capacity conditions. Traits included leaf area, root number, nodulation, gynophores, pods per plant, stomatal number and opening state, photosystem II photochemical activity, and fatty acid composition. Gynophore number was strongly related to pods per plant (R2 = 0.6688), while pod number explained 43.09% of yield variation (R2 = 0.4309). INIAP-ECU-11465 and INIAP-ECU-11832 achieved yields exceeding 4000 kg ha−1. Nodulation showed limited association with yield, whereas stomatal traits and photochemical performance revealed distinct physiological responses among accessions. Oleic acid predominated in the lipid profile (40.77–53.54%), indicating variability relevant to oil quality and oxidative stability. The agronomic, physiological, and biochemical diversity identified provides useful criteria for selecting promising peanut germplasm and supports further evaluation of these accessions in breeding strategies aimed at improving productivity and oil quality.