Consistency of farmer-named sweet potato cultivars and their physicochemical and color differentiation within a production region: a multivariate approach
摘要
Sweet potato is a crop of high nutritional and functional value widely grown in tropical regions. This study aimed to characterize sweet potato farmer-named cultivars grown by local farmers in Bahia, Brazil, based on physicochemical and color traits, and to evaluate the agreement of farmer-based classifications using multivariate approaches. Twenty samples representing different cultivars, collected in the municipalities of Cruz das Almas and Maragogipe and grown under crop cycles ranging from 90 to 120 days, were evaluated for resistant starch, moisture content, total carotenoids, antioxidant activity, and color parameters (L*, a*, and b*) of peel and pulp. Data were analyzed using analysis of variance, correlation analysis, principal component analysis, and hierarchical clustering. Substantial variability was observed, with color-related traits emerging as key components associated with physicochemical differentiation. Orange-fleshed germplasm (Cenoura and Abóbora) exhibited high carotenoid content and strong positive associations with chromatic parameters, particularly b*. The purple-fleshed cultivars (Polpa Roxa) was distinguished by high antioxidant activity and a unique multivariate profile. White- and cream-fleshed cultivars showed greater heterogeneity and lower differentiation based on color attributes. Resistant starch and moisture content were not associated with color traits, indicating independence from pigmentation-related attributes. Multivariate analyses revealed consistent patterns of variation, while variation across municipality and crop cycle did not show consistent patterns across traits. Farmer-named classifications showed a high degree of agreement with multivariate grouping for strongly pigmented cultivars, but lower agreement for those with less distinct phenotypic characteristics. Overall, physicochemical and color traits effectively characterized sweet potato diversity and support their use in germplasm evaluation and selection.