Ana Maria Adalid-Martínez

Sweet peppers (Capsicum annuum L.) are an important dietary source of antioxidants. Optimizing fruit antioxidant quality under reduced inputs is essential to valorize sustainable pepper production. Here, we evaluated seven Spanish genotypes (traditional/local, derived experimental hybrids and commercial hybrids) across six treatments combining two fertilization (100% and 50%) and irrigation (100% and 75%) regimes, with plant growth-promoting rhizobacteria (PGPR) applied under reduced fertilization treatments. Vitamin C and flavonoids were quantified by HPLC at the green-ripe and fully ripe stages, and carotenoids were determined spectrophotometrically at the fully ripe stage. Several genotypes largely maintained antioxidant content under stress treatments, whereas specific genotype × ripening stage combinations showed maximum increases in vitamin C (+102%), flavonoids (+86% for kaempferol) and carotenoids (+67% for yellow-orange carotenoids) under certain low-input treatments compared to the control. The PGPR effects on vitamin C and carotenoids were generally small, with occasional reductions. However, the PGPR increased total and some individual flavonoids by up to 96% (luteolin) in green-ripe Piquillo and 128% (quercetin) in fully ripe Isabel F1 fruits compared to the corresponding non-inoculated treatments. This multi-genotype, two ripening-stage evaluation identifies Spanish traditional germplasm and derived hybrids with stable or improved antioxidant profiles under low-input conditions and provides insight into PGPR effects. These results support the use of traditional genotypes in breeding for sustainable production.

The excessive use of irrigation water and fertilizers in agriculture raises serious environmental concerns, emphasizing the need for more sustainable practices. Screening genotypes with reduced nutrient and water requirements, combined with favorable responses to plant growth-promoting rhizobacteria (PGPR), offers a promising strategy for developing more sustainable farming systems. Seven sweet pepper genotypes (Capsicum annuum L.) were evaluated under six treatments, involving two fertilization levels (100% and 50% standard dose), two irrigation regimes (100% and 75% full irrigation), and PGPR inoculation applied under reduced fertilization. Yield, fruit weight, rhizosphere enzymatic activities, and soluble sugars in green and red fruits were evaluated. The genotype effect contributed significantly to all traits. Combined reductions in fertilizer and irrigation decreased average yield by 21.7%, while PGPR did not fully compensate for these losses. Alkaline phosphomonoesterase activity increased by 22.9% under low fertilization, whereas averaged catalase and dehydrogenase remained relatively stable regardless of PGPR. In green fruits, PGPR inoculation under combined stress conditions increased glucose and fructose concentrations by 11.6% and 13.9%, respectively, compared to uninoculated stressed plants, although sucrose decreased. At fully ripe stage, sugar composition was less responsive to treatments. These findings underscore the importance of genotype evaluation and the exploitation of genotype × treatment interactions in peppers breeding for sustainable farming.

Modern Solanum melongena varieties have been developed to improve the content of phenolics, sugars, and nutritionally relevant minerals in fruit. However, fruit composition might be altered due to abiotic stresses like salinity. Physiological and fruit quality traits were evaluated in four eggplant landraces under usual irrigation and moderately salty irrigation conditions (80 mM NaCl). Growing parameters measured included root length, leaf surface, and fresh weight, while fruit composition traits included sugars, phenolics, and mineral content determinations. Few differences were observed for agronomic traits, probably due to the mild tolerance of eggplant to salinity. Some varieties showed signs of salt tolerance like an increase in primary root length to overcome salt stress. Glucose was the metabolite more affected by the salt treatment in the fruit, while phenolic compounds and other metabolites studied were not altered. Significant differences were observed in the main minerals Na, K, Ca, P, and Mg, both between genotypes and treatments. Although salinity produced changes in some physiological and developmental traits, the composition of the fruit was not significantly modified for the accessions tested. Mineral, sugar, and phenolic contents were not particularly altered in unripe fruits, indicating tolerance of eggplant varieties to salinity in terms of fruit quality.

Peppers (Capsicum sp.) are used both as vegetables and/or spice and their fruits are used in a plethora of recipes, contributing to their flavor and aroma. Among flavor-related traits, pungency (capsaicinoids) and lately volatiles have been considered the most important factors. However, the knowledge of sugars is low, probably due to the fact peppers were historically considered tasteless. Here, using HPLC, we studied the content and profile of major sugars and capsaicinoids in a comprehensive collection of varietal types (genotype, G), grown under different growing systems (environment, E) in two years (Y) and considered the two main ripening stages (R). We found a major contribution to the ripening stage and the genotype in total and individual sugars and capsaicinoids. The year was also significant in most cases, as well as the G × E and G × Y interactions, while the growing system was low or nil. Ripening increased considerably in sugars (from 19.6 to 36.1 g kg⁻¹ on average) and capsaicinoids (from 97 to 142 mg kg⁻¹ on average), with remarkable differences among varieties. Moreover, sugars in fully ripe fruits ranged between 7.5 and 38.5 g kg⁻¹ in glucose and between 5.2 and 34.3 g kg⁻¹ in fructose, and several accessions reached total sugars between 40 and 70 g kg⁻¹, similar to tomatoes. The results reveal the importance of the genotype and the ripening for these traits, particularly sugars, which should be considered key for the improvement of taste and flavor in peppers.

The wild species Solanum incanum has been used as a donor parent for the development of a set of eggplant introgression lines (ILs), which are of interest for breeding for stress tolerances and relevant morpho-agronomic traits but could also be useful for breeding for fruit quality, due to the generally higher content in health-promoting compounds of S. incanum. The use of eggplant ILs with introgressions from S. incanum requires ensuring that glycoalkaloids levels are below safety limits. We evaluated 25 fruit composition traits, including proximate composition, sugars, acids, phenolics, glycoalkaloids, and minerals in a set of 16 eggplant ILs with S. incanum, both parents and the F₁, grown under two environments (open field and screenhouse). The results demonstrated that the parents were significantly different regarding most fruit composition traits. Large variation was found among the 16 ILs for all traits analyzed and a strong influence of the environment accounted for the variation of 17 out of the 25 traits evaluated. Although the S. incanum parent produced fruits with high levels of glycoalkaloids, the 16 ILs showed mean values of total glycoalkaloids below the currently accepted safety limit for human consumption (200 mg kg⁻¹ fresh weight). Overall, the ILs produced fruits that are safe for consumption, with nutritional and functional quality similar to the recipient parent. Furthermore, six putative QTLs were detected spread over chromosomes 3 for crude protein, 5 for malic and total acids, and 7 for chlorogenic acid and solamargine, and potential candidate genes were spotted for most of them, which provide new relevant information for eggplant breeding.

Information about the paper titled "INTRODUCTION AND DEVELOPMENT OF A PRACTICAL LESSON FOR IMPROVING THE COMPETENCE OF MASTER STUDENTS IN PLANT BREEDING: THE USEFULNESS OF SPECIFIC SOFTWARE IN PHENOTYPING TASKS" at IATED Digital Library

Background: Fool’s watercress (Apium nodiflorum) is an edible vegetable with potential as a new crop. However, little information is available regarding the antioxidant properties of the plant and the individual phenolics accounting for this capacity are unknown.Methods: The antioxidant properties of twenty-five wild populations were analysed and individual phenolics present in the species reported and compared with celery and parsley. The antioxidant activity was measured as the 2,2-diphenyl-1-picrylhydrazyl hydrate (DPPH) free radical scavenging capacity, and the total phenolics content (TPC) via the Folin-Ciocalteu procedure. The individual phenolics constituents were determined via high performance liquid chromatography (HPLC) as aglycones.Results: The average DPPH and TPC of fool’s watercress were 28.1 mg Trolox g⁻¹DW and 22.3 mg of chlorogenic acid equivalents g⁻¹DW, respectively, much higher than those of celery and parsley. Significant differences for both DPPH and TPC, which may be explained by either genotype or environmental factors, were detected among groups established according to geographical origin. Quercetin was identified as the major phenolic present in the leaves of the species, unlike parsley and celery, in which high amounts of apigenin and luteolin were determined. Quercetin represented 61.6% of the phenolics targeted in fool’s watercress, followed by caffeic acid derivatives as main hydroxycinnamic acids.Discussion: The study reports the high antioxidant properties of fool’s watercress based on a large number of populations. Results suggest that quercetin accounts for an important share of the antioxidant capacity of this potential new crop. The study also provides a basis for future breeding programs, suggesting that selection by geographical locations may result in differences in the antioxidant properties.

Capsicum peppers is one of the most important vegetables, with a well known nutritional properties, including phenolics. Breeding peppers adapted to organic agriculture and rich in bioactive compounds is of paramount importance for this sector since the demand of organic and healthy food is increasing in many countries. This is a preliminary study on the effect of genotype, growing conditions and their interaction on the main phenolics of peppers. Fruits from four Capsicum annuum (BGV-10582, Bierzo, Bola and Piquillo) and one C. chinense (ECU-994) accessions, were cultivated under organic and conventional practices and main phenolic compounds quercetin and luteolin were analysed by high performance liquid chromatography (HPLC). Differences were found among accessions for both compounds in the studied accessions, particularly ECU-994. Differences for each phenolic compound were also detected between growing systems. Moreover, considerable interaction between genotype and growing conditions was found, suggesting that there are ample opportunities for selecting peppers with high content in phenolics and specifically adapted to organic cultivation.

Diplotaxis erucoides is an edible plant with potential for marketing. Here, we analysed the influence of the growing conditions in this species, D. tenuifolia and Eruca sativa, and studied the relation among the ascorbic (AA) and dehydroascorbic (DHA) acid forms. Plants were grown in the late winter-spring season under two conditions, greenhouse and field. The contents in AA, DHA and vitamin C (VC) were analysed by HPLC. The content of VC and AA were, in general, remarkable higher in the plants grown in the field. On the other hand, the mean percentage of DHA was less than 11%, being in this case higher for plants grown in the greenhouse. Thus, growing this potential crop in the field seems a better option in order to increase the content in VC, being AA the main form present at the moment of gathering.