Fruit composition profile of pepper, tomato and eggplant varieties grown under uniform conditions.

The study of the diversity within and between major Solanaceae crops (pepper, tomato, eggplant) is of interest for the selection and development of balanced diets. We have measured thirty-six major fruit composition traits, encompassing sugars, organic acids, antioxidants and minerals, in a set of 10 accessions per crop for pepper, tomato and eggplant, grown under the same cultivation conditions. The aim was to evaluate the diversity within species and to provide an accurate comparison of fruit composition among species by reducing to a minimum the environmental effect. Pepper, tomato and eggplant had a clearly distinct composition profile. Pepper showed the highest average content in total sugars and organic acids. Fructose and glucose were the major sugar compounds in the three species, although in pepper and tomato sucrose was present only in trace amounts. Citric acid was the major organic acid in pepper and tomato, while in eggplant it was malic acid. Pepper and eggplant had the highest total antioxidant activity. Vitamin C content was much higher in pepper than in tomato and eggplant, while eggplant accumulated high concentrations of chlorogenic acid. Furthermore, eggplant was the species with higher content in most minerals, particularly for K, Mg and Cu, while pepper was the richest in Fe. Due to their complementary nutritional profiles, a combined regular consumption of the three vegetables would supply more than 20% of the Dietary Reference Intake of several of the analysed phytochemicals. The large diversity within each species is of interest for selecting varieties with better nutritional and organoleptic profiles, as well as for breeding new cultivars.

A Comparison of Landraces vs. Modern Varieties of Lettuce in Organic Farming During the Winter in the Mediterranean Area: An Approach Considering the Viewpoints of Breeders, Consumers, and Farmers.

The interest of farmers in growing lettuce landraces is increasing, as landrace varieties prove particularly appealing to consumers striving to purchase natural, local, and high-quality produce. Although high genetic diversity exists in the landrace gene pool, this has scarcely been studied, thus hindering landrace utilization in agriculture. In this study, we analyzed the genetic diversity and the agronomic and quality traits of lettuce landraces in organic agrosystems, by characterizing 16 landraces and 16 modern varieties. We compared 29 morphological descriptors, and several traits relating to agronomic behavior (total and commercial weight, resistance to Bremia lactucae) and quality (color, chlorophyll, dry matter, and total sugars). Trials were conducted in two localities and managed following organic farming practices. Moreover, farmers and consumers participated in the phenotyping of accessions by scoring yield, resistance to B. lactucae, appearance, and taste acceptance. Results show that cultivar group, rather than the genetic origin (modern vs. landrace), is the major source of variation for all agronomic and quality traits. Batavia and Butterhead were highly homogeneous cultivar groups, while Cos accessions showed a much higher intra-varietal diversity. There was also a clear separation between modern and landrace varieties of Oak leaf. Fifteen out of the 16 evaluated landraces presented a high susceptibility to the particular B. lactucae race isolated from the experimental field - a new race not reported before. Breeding programs intended to introgress genetic resistance to this pathogen are a major priority to recover the cultivation of lettuce landraces. Principal component analysis (PCA), conducted on all quantitative data, showed a clear differentiation between modern varieties and landraces, mostly related to their commercial weight and susceptibility to B. lactucae. These seem the most important traits influencing farmer and consumer evaluations. Farmers showed a high capacity for characterizing the samples and agreed with consumers when scoring for the external appearance. It is proposed that farmers and consumers should be included in the phenotyping platforms in future research projects aiming for recovery of landraces.