-grown grapevines ( Hellman et al., 2006 ). ABA has also been sprayed on table grape clusters during the veraison stage to promote anthocyanin accumulation and thus enhance color development ( Peppi et al., 2007 ). Based on a greenhouse study, ABA has been reported
Yi Zhang and Imed Dami
Maria Papafotiou, Barbara Avajianneli, Costas Michos and Iordanis Chatzipavlidis
ones have all three colors. We found no reports in the literature on the type of pigments involved in the coloration of croton leaves; thus, anthocyanins, which usually are responsible for red coloration in plant tissues ( Mulder–Krieger and Verpoorte
Creighton L. Gupton
Anthocyanin-deficient dewberries in Mississippi were evaluated for possible use as a source of marker genes for blackberries. Ratios of normal to anthocyanin-deficient plants from test crosses suggested single-locus control of stem color, with anthocyanin deficiency a recessive trait. Its simple inheritance and easy identification in seedlings provide potential for anthocyanin deficiency (t) to be used as a marker gene in blackberry genetic studies.
Genes for reduced carotene content (white, yellow, and pale orange) and for anthocyanin pigmentation were identified in Daucus carota PI 173687 and in progeny derived from crosses of this Plant Introduction with orange-rooted inbred lines. Monogenic inheritance for each of these root color variants was examined. Mixed cell cultures of callus derived from white and orange roots indicated autonomy of carotene gene expression in carrot cell cultures. Strategies for incorporation of carrot genes conditioning pigment content will depend upon gene combinations sought.
Aparna Gazula*, Matthew D. Kleinhenz, Joseph C. Scheerens, Peter P. Ling and John G. Streeter
In addition to their physiological and metabolic roles, anthocyanin (Antho) levels in lettuce contribute to visual and nutritional value-based assessments of crop quality. Although 7 genes are now thought to help regulate Antho synthesis, deposition and/or degradation in lettuce, the genetic and abiotic controls of Antho levels remain less well characterized in lettuce than other plants. Previous greenhouse studies demonstrated that Antho levels in diverse lettuce varieties are a function of temperature and lighting regimen. Here, three strongly related Lolla Rossa-type varieties (`Lotto', `Valeria', and `Impuls') varying in the number of genes controlling intensity of anthocyanins were subjected to differential temperature conditions in growth chambers to better discern the independent and interactive effects of temperature (T) and variety (V) on Antho levels. Fifteen day-old seedlings were placed into one of three chambers maintained at 20 °C day/night (D/N), 30 °C/20 °C D/N or 30 °C D/N. Antho levels were measured in leaf tissue collected 30 d after transplanting. The entire experiment was replicated twice. Although significant, the T x V interaction resulted from differences in the magnitude, not direction, of the change in Antho concentrations among varieties with changes in T. This suggests that T was a main driver of Antho levels in this study. Regardless of V, Antho concentrations were highest, moderate and lowest after growth at 20 °C D/N, 30 °C/20 °C D/N and 30 °C D/N, respectively. Likewise, regardless of T, Antho levels followed the pattern `Impuls' (three genes) > `Valeria' (two genes) > `Lotto' (one gene). Correlations among instrumented and human eye-based evaluations of color are also being tested in samples from both studies.
Zen-hong Shü, Cheng-chung Chu, Lee-juan Hwang and Ching-shung Shieh
A study was conducted to assess the combined effects of light, temperature and sucrose on color, weight, diameter, and soluble solids of the skin of wax apple (Syzygium samarangense Merr. & Perry) fruits. Skin disks were cultured in a factorial arrangement of two light levels [dark or light (300 μmol·m-2·s-1)] as subplots and three sucrose concentrations (0%, 3%, or 6%) as sub-subplots within three temperature levels (20, 25, or 30 °C) as whole plot treatments. Weight, diameter, soluble solids concentration (SSC), and anthocyanin content were measured 2 weeks after incubation. Light increased SSC and anthocyanin, but reduced the increase in weight and diameter. Increasing the temperature limited increase in diameter and anthocyanin content. Weight, SSC, and anthocyanin contents increased in a linear fashion with concentration of sucrose in the culture solution. However, none of the three factors played a unique role in anthocyanin synthesis in wax apple. Among the 18 combinations, light/20°C/6% sucrose gave the highest SSC and anthocyanin content, while dark/20°C/6% sucrose produced the largest diameter.
Shawn A. Mehlenbacher and Maxine M. Thompson
A chlorophyll deficiency expressed as yellowing of leaves was observed in hazelnut (Corylus avellana L.) progenies. Segregation ratios approximated 3 green: 1 yellow, indicating control by a single recessive gene designated chlorophyll deficient #1, for which the symbol c, is proposed. `Barcelona', `Butler', `Compton', `Lansing', Willamette', and the ornamental selection `Redleaf #3' are heterozygous. Pedigree analysis strongly suggests that all heteroxygotes inherited the recessive allele from `Barcelona'. A cross of `Barcelona' with the yellow-leafed ornamental Corylus avellana L. var. aurea Kirchn. produced no yellow-leafed seedlings, indicating that the chlorophyll deficiencies from these two sources are controlled by different loci. Progenies segregating simultaneously for this trait and the gene controlling presence of anthocyanin indicated that the two traits are inherited independently. Seedlings deficient in chlorophyll but with anthocyanin were able to survive under field conditions, while leaves of yellow-leafed seedlings lacking anthocyanin became scorched and the trees died.
I. Iglesias, J. Graell, G. Echeverría and M. Vendrell
The influence of supplemental sprinkler irrigation on fruit color of `Oregon Spur Delicious' (Trumdor) apples (Malu×domestica Borkh.) was evaluated in the area of Lleida (NE Spain) over a 3-year period. Cooling irrigation was applied for 2 hours daily for 25-30 days preceding the harvest. Three treatments were evaluated: 1) control without overtree sprinkler irrigation; 2) sprinkler irrigation applied at midday; and 3) sprinkler irrigation applied at sunset. Fruit color was significantly affected by the cooling irrigation and also by the weather of the particular year. Increased red color and higher anthocyanin content resulted from sprinkler irrigation, especially when applied at sunset. At harvest, anthocyanin content was correlated with a*/b* and hue angle, suggesting that the colorimeter measurements could provide a nondestructive estimate of anthocyanin content.
Hallie G. Dodson, J.B. Murphy and T.E. Morelock
Anthocyanins are naturally occurring plant pigments that are classified as flavonoids. Anthocyanins have important antioxidant properties which may help in prevention of cancer, arthritis, and cardiovascular disease. Finding common sources and possibly increasing levels of anthocyanins in food could be important to human health. This research project determined amount and type of anthocyanins in 16 cultivars and breeding lines of cowpeas (Vigna unguiculata). The information obtained from this research project will be used to improve anthocyanin content of cowpeas by breeding. Of the 16 cultivars and breeding lines, only a black cowpea breeding line, 95-356, contained measurable levels of 3 types of anthocyanins: delphinidin, peonidin, and an unknown anthocyanin. Total anthocyanin content was 0.00242 mg·g–1, which is equal to 0.21 mg per ½-cup serving. In another study with 95-356 Rabi A. Musah, found a total anthocyanin content of 121.26 mg per serving and also found three other types of anthocyanins. The difference in the studies could be explained by the storage time of two weeks after the anthocyanins were extracted, but before they were eluded in this study. Additional studies are needed to determine if cowpeas can provide anthocyanin levels comparable to other fruits and vegetables.
David L. Ehret, Brenda Frey, Tom Forge, Tom Helmer and David R. Bryla
irrigation and water management, on blueberry fruit quality attributes such as berry size, firmness, and shelf life remain largely undefined. Blueberries contain high levels of anthocyanins and other flavonoids, which show anticarcinogenic properties and are