The influence of genotype, cooking method, and storage treatments on potato compounds associated with improved human health was analyzed. Antioxidant activity (AA), total phenolics (TP), and total carotenoids (xanthophyll carotenoids, CAR) were determined in eight genotypes using 2,2-diphenyl-1-picrylhydrazyl (DPPH), Folin-Ciocalteu reagent, and spectrophotometric absorbance, respectively. Individual phenolic and carotenoid composition was analyzed using high performance liquid chromatography (HPLC) in three genotypes of potato. Samples were subjected to a combination of storage conditions for approximately 4 months (non-stored or stored for 110 days at either 4°C, 4°C with an additional 10 days of reconditioning at 20°C, or 20°C storage) and cooking methods (baking, boiling, frying, or microwaving); an uncooked sample was used as a control. The non-stored samples had lower amounts of CAR, AA, and TP along with the individual compounds compared to the various storage regimes, while the recondition storage treatment produced equal or higher levels of TP and individual phenolics than any other storage regime. No cooking and boiling resulted in significantly lower AA and TP, as compared to baking, frying and/or microwaving. Baking, frying and/or microwaving also increased the levels of chlorogenic acid, caffeic acid, (-) epicatechin, p-coumaric acid and vanillic acid, but decreased quercetin dihydrate when compared to uncooked samples. Most health promoting compounds were enhanced by one or both postharvest processing parameters (storage and cooking); however, t-cinnamic acid, and lutein were not affected.Resumen Se analizó la influencia del genotipo, del método de cocinado y de tratamientos en el almacén, sobre los compuestos de papa asociados con el mejoramiento de la salud humana. Se determinó la actividad antioxidante (AA), fenoles totales (TP), y carotenoides totales (carotenoides xantofílicos, CAR), en ocho genotipos, usando 2,2-difenil-1-picrilhidrazilo (DPPH), el reactivo de Folin-Ciocalteau, y la absorbancia espectrofotométrica, respectivamente. Se analizaron los fenoles individuales y la composición de los carotenoides usando cromatografía de líquidos de alta resolución (HPLC) en tres genotipos de papa. Las muestras estuvieron sujetas a una combinación de condiciones de almacenamiento por aproximadamente cuatro meses (sin almacenar, o almacenadas por 110 días ya fuera a 4°C, a 4°C con diez días adicionales de reacondicionamiento a 20°C, o a 20°C en el almacén), y métodos de cocinado (horneadas, hervidas, fritas, o en el horno de microondas); se usó una muestra sin cocinar como testigo. Las muestras sin almacenar tuvieron las cantidades más bajas de CAR, AA, y TP, junto con los compuestos individuales comparados a los diversos regímenes de almacenamiento, mientras que el tratamiento de reacondicionamiento en el almacén produjo niveles iguales o mayores de TP y de fenoles individuales que cualquier otro régimen de almacenamiento. Sin cocinar y hervidas resultaron en contenido más bajo de AA y TP, comparadas ...

Total antioxidant activity was evaluated in 40 tuber-bearing Solanum species. Accessions identified in a broad screen as having high antioxidant activity were fine screened via high performance liquid chromatography (HPLC) to determine specific phenolic compounds present. The objective of the study was to identify tuber-bearing Solanum species that are higher in antioxidants than in currently available cultivated varieties and breeding lines, and to investigate the variability for this trait among accessions within species and genotypes within accessions. The identified accessions will be used as a source of germplasm to develop potato cultivars containing increased levels of antioxidant compounds. In a broad screen for total antioxidant activity, the 40 tuber-bearing species showed a wider range of variability than cultivated varieties and breeding lines. Solanum pinnatisectum and S. jamesii accessions consistently ranked among the highest in antioxidant activity and phenolic content. Based on the 2, 2-diphenyl-1-picrylhydrazyl (DPPH) assay, antioxidant activity in the wild species ranged from 48 to 824 μg trolox eq/gfw. HPLC analysis revealed that the phenolic content of these species was primarily composed of chlorogenic and caffeic acids. Other phenolics identified were p-coumaric acid, rutin hydrate, vanillic acid, epicatechin, t-cinnamic acid, gallic acid, and salicylic acid. The highest phenolic content found among the accessions was five-fold higher than the highest of the cultivated genotypes.Resumen La actividad antioxidante total fue evaluada en 40 especies tuberíferas de Solanum. Las accesiones que mostraron actividad antioxidante en un tamizado amplio fueron sometidas a un tamizado más fino por medio de cromatografía líquida (HPCL) para determinar los compuestos fenólicos específicos presentes. El objetivo de este estudio fue identificar las especies tuberíferas de Solanum que tienen contenido más alto de antioxidantes que las variedades y líneas de mejoramiento e investigar la variabilidad de esta característica entre las accesiones dentro de especies y genotipos. Las accesiones identificadas serán usadas como fuente de germoplasma para desarrollar cultivares de papa que contengan niveles altos de compuestos antioxidantes. En un tamizado amplio para actividad total antioxidante, las 40 especies tuberíferas mostraron un rango más amplio de variabilidad que las variedades cultivadas y que las líneas mejoradas. Las accesiones de Solanum pinnatisectum y S. jamesii dieron consistentemente grados más altos en actividad antioxidante y contenido fenólico. En base a la prueba 2, 2-difenil-1-picrilhidrazil (DPPH), la actividad antioxidante en las especies silvestres fue de 48 a 824 μg trolox eq/gfw. El análisis HPLC reveló que el contenido de estas especies estaba principalmente compuesto de los ácidos clorogénico y cafeico. Otros fenoles identificados fueron ácido pcumárico, rutina hidrato, ácido vanílico, epicatequín, ácido t-cinámico, ácido gálico y ácido salicílico. El contenido fenólico en las accesiones...

Some tuber-bearing wild potato species are reportedly higher in potential health-promoting traits, such as antioxidant activity (AOA) and total phenolic content (TP), than commercial cultivars; therefore, they could be used as parental material in breeding for high AOA and TP. However, using wild species might result in progenies that are toxic for human consumption because of the presence of high total glycoalkaloids (TGAs) and other unknown compounds. Therefore, wild potato accessions should be screened for cytotoxicity before their introduction into breeding programs. The objective of this study was to investigate antiproliferative activity and cytotoxicity of tuber extracts from 15 Solanum jamesii accessions on human HT-29 colon and LNCaP prostate cancer cell lines in vitro. Also, correlations among AOA, TP, TGA, and antiproliferative activity were determined. The tuber extracts significantly inhibited proliferation of HT-29 and LNCaP cell lines and were not cytotoxic to the cells compared to the control (DMSO). The antiproliferative activity exhibited by tuber extracts was not due to necrosis, because the amount of lactate dehydrogenase (LDH) released from cells incubated with the extracts was not significantly different from that released from cells incubated without extracts (control). Colon cancer cells were more responsive to tuber extract treatment than prostate cancer cells. In both HT-29 and LNCaP cells, there were no observable significant correlations between antioxidant activity (DPPH and ABTS) and inhibition of cell proliferation or between TP and cell proliferation inhibition. Also, glycoalkaloids did not exhibit significant correlations with the inhibition of cancer cell proliferation. Findings of this study show that S. jamesii accessions probably pose no cytotoxic effects when used as parental material in improving the nutritional value of potato cultivars. Correlation results, along with cell proliferation data, suggest that not only the compounds measured in this study but also other bioactive compounds present in the matrix acting additively or synergistically may be more responsible for the antiproliferative effects of potato tuber extracts than higher concentrations of a single or group of compounds.

Over the last three decades, broccoli (Brassica oleracea L., Italica Group) hybrids made by crossing two inbred lines replaced open-pollinated populations to become the predominant type of cultivar. The change to hybrids evolved with little or no understanding of heterosis or hybrid vigor in this crop. Therefore, the purpose of the present study was to determine levels of heterosis expressed by a set of hybrids derived by crossing relatively elite, modern inbreds (n = 9). An additional objective was to determine if PCR-based marker derived genetic similarities among the parents can be useful to predict heterosis in this crop. Thirty-six hybrids derived from a diallel mating design involving nine parents were evaluated for five horticultural characters including the head characteristics of head weight, head stem diameter, and maturity (e.g., days from transplant to harvest), and the plant vigor characteristics of plant height, and plant width in four environments. A total of 409 polymorphic markers were generated by 24 AFLP, 23 SRAP and 17 SSR primer combinations. Euclidean distances between parents were determined based on phenotypic traits. About half of the hybrids exhibited highparent heterosis for head weight (1-30 g) and stem diameter (0.2-3.5 cm) when averaged across environments. Almost all hybrids showed highparent heterosis for plant height (1-10 cm) and width (2-13 cm). Unlike other traits, there was negative heterosis for maturity, indicating that heterosis for this character in hybrids is expressed as earliness. Genetic similarity estimates among the nine parental lines ranged from 0.43 to 0.71 and were significantly and negatively correlated with highparent heterosis for all traits except for stem diameter and days from transplant to harvest. Euclidean distances were not correlated with heterosis. With modern broccoli inbreds, less heterosis was observed for head characteristics than for traits that measured plant vigor. In addition, genetic similarity based on molecular markers was more highly correlated with plant vigor characteristics than head traits. Unlike with molecular marker-based estimates of genetic similarity, euclidean distance determined using phenotypic trait data was not predictive of heterosis. In conclusion, this study has documented heterosis in Brassica oleracea L., and the ability to predict heterosis in this crop using molecular marker-based estimates of genetic similarity among parents used in producing the hybrid.

The inheritance of antioxidant activity (AOA) and its association with seedcoat color was investigated in cowpea [Vigna unguiculata (L.) Walp.]. Four advanced cowpea lines, ARK95-356 (black seedcoat) and ARK98-348 (red seedcoat), which were high (H) in AOA, and ARK96-918 (cream seedcoat) and LA92-180 (cream seedcoat), which were low (L) in AOA, were selected from the 2002 Regional Southernpea Cooperative Trials. They were crossed in a complete diallel mating design, generating F 1 , F 1´ (1st generation and 1st generation reciprocal cross, respectively), F 2 , F 2´ (2nd generations from F 1 , F 1´) , BC 1 , and BC 2 (backcrosses to parents 1 and 2, respectively) populations. Individual seeds were ground and samples were extracted in methanol and analyzed for AOA using the free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH) method. Combining ability tests using Griffi ngʼs Method I Model I indicated presence of highly signifi cant general combining ability (GCA), specifi c combining ability (SCA), and reciprocal (RE) and maternal (MAT) effects, with pigmented lines exhibiting positive GCA and MAT, while nonpigmented lines exhibited negative GCA and MAT. AOA in the F 1 was not signifi cantly different from the maternal parent, with seedcoat color also resembling the maternal parent. Segregation for seedcoat color was observed in the F 2 and F 2´. Additive, dominance, and epistatic effects were signifi cant. The broad sense heritability estimate was 0.87. Minimum number of genes responsible for AOA was estimated at fi ve. Factors governing high AOA appeared to be the same as those responsible for seedcoat color, with apparent pleiotropic effects. In conclusion, breeding for high AOA in cowpea is possible using highly pigmented parental lines.