Genotype-by-environment interaction (G×E) is a fundamental concern in plant breeding since it hinders developing genotypes with wide geographical usefulness. Analysis of variance (ANOVA) has been widely used to interpret G×E, but it does not elucidate the nature and causes of the interaction. Stability analysis provides a summary of the response patterns of genotypes to different growing environments. Two classes of phytochemicals with putative health promoting activity are carotenoids and tocopherols that are relatively abundant in broccoli. Growing clinical and epidemiological evidence suggests that vegetables with enhanced levels of these phytochemicals can reduce the risk of cancer, cardiovascular, and eye diseases. The objective of this study is to have better understanding of the genetic, environmental and G×E interaction effects of these phytochemicals in broccoli to determine the feasibility of the genetic enhancement. The ANOVA and Shukla's stability test were applied to a set of data generated by the HPLC analysis of different carotenoid and tocopherol forms for six broccoli accessions grown over three environments. The ANOVA results show a significant G×E for both phytochemicals that ranged from 22.6% of the total phenotypic variation for beta-carotene to 54.0% for delta-tocopherol while the environmental effects were nonsignificant. The genotypic effects ranged from as low as 1% for alpha-tocopherol to 31.5% and 36.0% for beta-carotene and gamma-tocopherol, respectively. Stability analysis illustrated that the most stable genotype for all phytochemicals is Brigadier. The results suggest that feasibility of the genetic enhancement for major carotenoids and tocopherols. A second experiment that includes a larger set of genotypes and environments was conducted to confirm the results of this study.
Khalid E. Ibrahim, Kanta Kobira, and John A. Juvik
Claire H. Luby, Rachael Vernon, Hiroshi A. Maeda, and Irwin L. Goldman
Vitamin E is a group of eight lipid-soluble antioxidants (α-, β-, γ-, and δ- tocopherols and tocotrienols, collectively known as tocochromanols) that are synthesized in the plastids of plants, algae, and some cyanobacteria ( Mène-Saffrané and
Thomas C. Koch* and Irwin L. Goldman
Carotenoids (provitamin A) and tocopherols (vitamin E) are powerful antioxidants in plants and in the human diet. Carrot (Daucus carota) has been selected for increased levels of carotenoids, contributing to its orange color and reported health benefits. Selection for increased tocopherol has shown success in seed oils, but little progress has been made in the edible portions of most vegetable crops. HPLC measurement following a simultaneous heptane extraction of both compounds has shown a significant (P ≤ 0.001) positive correlation of α-tocopherol with α-carotene (r = 0.65) and β-carotene (r = 0.52). To increase both the tocopherols and carotenoids in plants, 3 populations have been established from select open-pollinated varieties grown in 2002. These populations consist of half-sib families with these differing selection schemes: based strictly on increased α-tocopherol levels; an index to increase α-carotene, β-carotene and α-tocopherol; and a random population in which no selection is occurring. After one cycle of selection, populations were grown on muck soil during the summer of 2003. Compared with the random population, an increase of 24.68% in α-tocopherol concentration was recorded for the population selected strictly on α-tocopherol while increases of 8.47% in α-tocopherol, 9.31% in α-carotene and 7.31% in β-carotene were recorded for the population with index selection. The continuation of these carrot populations shows promise to produce carrot germplasm with improved human nutritive value.
Cristián Vela-Hinojosa, Héctor B. Escalona-Buendía, José A. Mendoza-Espinoza, Juan M. Villa-Hernández, Ricardo Lobato-Ortíz, Juan E. Rodríguez-Pérez, and Laura J. Pérez-Flores
Tomato fruit are an excellent source of antioxidants and contribute significantly to human health because of their anti-inflammatory, antiallergenic, and antithrombotic properties. Carotenoids and tocopherols are among the major lipophilic
Vanessa E.T.M. Ashworth, Haofeng Chen, Carlos L. Calderón-Vázquez, Mary Lu Arpaia, David N. Kuhn, Mary L. Durbin, Livia Tommasini, Elizabeth Deyett, Zhenyu Jia, Michael T. Clegg, and Philippe E. Rolshausen
from ground level to the tip of the tree. Canopy diameter was determined at the widest part of the canopy in two orientations: parallel to the orchard row and perpendicular to the row, with the two values averaged. Fruit nutrient composition [α-tocopherol
Myung-Min Oh, Edward E. Carey, and C.B. Rajashekar
, including α-tocopherol, β-carotene, and flavonoids, in a wide range of plant species ( Keles and Öncel, 2002 ; Munné-Bosch et al., 2001 ; Tattini et al., 2004 ; Zobayed et al., 2007 ). Because lettuce is the most commonly consumed fresh leafy vegetable
Carmen Mena, Alejandra Z. González, Raúl Olivero-David, and María Ángeles Pérez-Jiménez
methanol extraction and subsequent reaction with Folin–Ciocalteu reagent and measured at a wavelength of 725 nm ( Vázquez-Roncero et al., 1975 ). Results are expressed as milligrams of caffeic acid equivalents per kilogram of oil. Total tocopherol content
Shiva Ram Bhandari, Bo-Deul Jung, Hum-Young Baek, and Young-Sang Lee
and dihydrocapsaicin were obtained from Fluka. Standards for fatty acid methyl ester were acquired from Supelco, and vitamin E (α-, β-, γ- and δ-tocopherols) standards were purchased from Merck (Germany). Chemicals such as acetonitrile, acetic acid, n
Charles R. Brown, David Culley, Meredith Bonierbale, and Walter Amorós
as nanoMoles of α-tocopherol equivalents/100 g FW. Statistical analysis. Analysis of variance following a randomized complete block design and Duncan's multiple range test was applied to the means ( Steel and Torrie, 1980 ). Correlations were
Flavonoid content and antioxidant activity in peel and pulp samples of four different cactus pear fruit varieties were investigated. Major cactus fruit flavonoids were quercetin, kaempferol, and isorhamnetin. Greater amount of quercetin was found in the pulp compared with the peel samples in all varieties examined. Both kaempferol and isorhamnetin were found in at least three of the varieties (Opuntia ficus-indica; O. lindheimeri; O. streptacantha) exclusively in the peel samples. Generally, pulp tissue samples of all the cactus fruit varieties contained greater ascorbic acid, glutathione, alpha-tocopherol and beta-carotene and antioxidant activities than the peel tissue samples. Total flavonoids correlated well with antioxidant activity (r 2 = 0.89). Ascorbic acid had the highest antioxidant activity, followed by glutathione, beta-carotene, and alpha-tocopherol on equimolar basis.