flavonoids (anthocyanins) ( Iwata et al., 1979 , 1985 ) or copigmentation of both carotenoids and flavonoids ( Kamemoto and Kuehnle, 1996 ) as seen in the cultivars ‘Honduras’ and ‘Terra’. The anthocyanin pigments are mainly pelargonidin 3-rutinoside and
Winston Elibox and Pathmanathan Umaharan
Mustafa Özgen, Karim M. Farag, Senay Ozgen and Jiwan P. Palta
Highly colored cranberries are desired for both fresh and juice markets. Berries accumulate more color when allowed to stay on the vines longer. However, early fall frosts often force growers to harvest before the fruit has reached its optimal color. This is especially true for the berries under the canopy. No product is currently available for grower to accelerate the color development in cranberries. Result from recent studies suggests that a natural lipid, lysophosphatidylethanolamine (LPE), can accelerate color production in fruit and, at the same time, promote shelf life. LPE is a natural lipid and is commercially derived from egg and soy lecithin. The influence of LPE on anthocyanin accumulation and storage quality of cranberry fruit (Vaccinium macrocarpon Ait. `Stevens') was studied. Cranberry plants were sprayed with LPE at about 4 weeks before commercial harvest at multiple locations. Experiments were conducted in 1997, 1998 and 1999. Fruit samples were taken at 2 and 4 weeks after spray application to determine the changes in the fruit color. Plots were wet harvested using a standard commercial method and stored in a commercial cold storage facility. Marketable fruit were evaluated at 1 and 2 months after cold storage to determine effect of LPE on shelf life of cranberries. In general, a preharvest application of LPE resulted in a 9% to 27% increase in fruit anthocyanin concentration compared to the control. LPE treatments also resulted in 8% to 12% increase in marketable fruit compared to the control following cold storage. Influence of LPE on fruit quality was more apparent after 1 month of storage. These results are consistent with the observed effects of LPE on tomatoes. Interestingly ethanol application also enhanced storage quality. Our results suggest that a preharvest application of LPE may have the potential to enhance color and prolong shelf life of cranberry fruit.
Surawit Wannakrairoj and Haruyuki Kamemoto
Mark J. Bassett
The inheritance of intensified anthocyanin expression (IAE) in a syndrome of plant organs of common bean (Phaseolus vulgaris L.) was investigated. A selection from accession line G07262, having white flowers with blue veins on the wing petals and a long, white micropyle stripe on black seedcoats, was used as the source of IAE syndrome. G07262 was crossed with three genetic tester stocks based on Florida dry bean line 5-593, which has the flower and seedcoat genotype T P [C r] Z J G B V Rk. The tester stocks were 5-593 (black seed and bishops violet flowers), t z bip bipunctata BC1 5-593 (a partly colored seedcoat), and v BC2 5-593 (mineral brown seedcoat and white flowers). Analysis of the F1 and F2 data from the test cross G07262 × t z bip bipunctata BC1 5-593 demonstrated that 1) G07262 has genotype t p mic V; 2) genotype t/t prevents expression of IAE syndrome by a dominant gene (Prp i -2) carried cryptically by G07262, i.e., T/-is required for expression of the gene; and 3) Prp i -2 may (preliminary data) express blue veins on white flowers with t V. From the cross with v BC2 5-593, an F4 selection for white flowers with red banner back and mineral brown seedcoats (due to v) was made. When the F4 selection was crossed with 5-593, analysis of the F2 progeny demonstrated that G07262 carries a dominant gene for IAE syndrome, which expresses with V/- but not with v/v. From the test cross 5-593 × G07262, a series of additional cycles of selection and test crosses (including the dark red kidney tester c u b v rk d BC1 5-593) were made, and two new two-colored seedcoat patterns were developed that have never been previously reported. In a test cross with one of them, F2 data demonstrated that the dominant gene for IAE syndrome from G07262 is independent of the C locus, and the gene symbol Prp i -2 is proposed for this IAE syndrome gene to distinguish it from the previously reported IAE syndrome gene [c u Prp i]. A gene symbol reconciliation was made for all previous work with inheritance of IAE syndrome and purple pod genes without the syndrome.
Matthew D. Kleinhenz, Aparna Gazula, Joseph C. Scheerens and Darla G. French
Shading effects on chlorophyll a (ChlA), chlorophyll b (ChlB) and anthocyanin (Antho) concentrations were examined at three developmental stages in four varieties of lettuce (Lactuca sativa) grown under contrasting temperature regimens in the greenhouse. Seedlings were transplanted to pots and grown at 30 °C (86.0 °F) day/night (D/N) (Study 1) or 30/18 °C (86.0/64.4 °F) D/N (Study 2). One-half of all plants in each study were positioned under bottomless shade boxes which reduced incoming light intensity by 50%. Pigment concentrations were measured in leaf tissue 9, 16, and 23 days after transplanting. Each study was repeated twice. Regardless of temperature regimen, variety influenced all pigment concentrations, while shading affected, primarily, Antho concentrations. ChlA and ChlB concentrations were influenced by growth stage. In Study 1, chlorophyll concentrations were significantly greater in `Green Vision' than `New Red Fire' or `Rolina', but not `Galactic'. Also, Antho concentrations were significantly greater in `Galactic' than the other varieties. In Study 2, chlorophyll concentrations were greatest in `Green Vision', with similar concentrations among the remaining varieties. Antho concentrations were greatest in `Galactic', intermediate in `New Red Fire' and `Rolina', and lowest in `Green Vision'. Shading significantly reduced Antho concentrations in `Galactic' and `Rolina' under both temperature regimens and `New Red Fire' at 30/18 °C D/N, but increased Antho concentrations in `Green Vision'. Chlorophyll concentrations tended to decrease with plant age. Pigment concentration data clarified what was apparent to the unaided eye—namely, that the amount and intensity of green and red color varied among plants subjected to different shading and temperature treatments. Therefore, these data may aid in developing strategies to achieve targeted levels of pigmentation (especially red) in lettuce, an important criterion of crop quality and potential market value.
James O. Denney and George C. Martin
Fruit removal force (FRF) and percent leaf drop (LD) of fruit-bearing olive (Olea europaea L.) shoots were examined 120 hours after being sprayed with ethephon at 600 mg·liter-1 and held under controlled-environmental conditions analogous to those found in the field in California at harvest time in mid-October. FRF was not significantly affected by solution pH, but FRF of all treated shoots was significantly lower than that of the untreated controls. Only at pH 5 was percent LD significantly greater than that of the controls, but, of the shoots treated with ethephon, the lowest percent LD occurred at pH 3. Percent LD after treatment with ethephon at pH 3 was not affected by application time, but FRF was significantly less than the controls' when shoots were treated at 7 am or 12 pm but not at 5 pm or 10 pm. Adding NAA to the ethephon solution raised FRF and adding BA lowered FRF compared to ethephon alone. Adding NAA or BA did not mitigate percent LD significantly. Adding BA advanced anthocyanin production in fruit. Ethephon penetration of rachides was ≈70% that of petioles. Correlation between ethephon penetration of petioles and percent LD was greater than that between penetration of rachides and FRF. Correlation was significant for both tissues only in the 12 pm pH 3 treatment; correlation was also significant for petiole penetration and percent LD at pH 5. Autoradiographic studies of the 14C-ethephon penetration showed no pH effect, greater penetration into petioles than rachides, and that radioactivity was limited largely to intercellular spaces, with accumulation in vascular bundles, especially xylem. Regardless of treatment, FRF and percent LD are negatively correlated (r 2 = 0.615). Mean results to be expected using ethephon as an olive harvest aid under these conditions are an FRF of ≈3 N and a percent LD of ≈15%. The desired low FRF and percent LD were obtained by applying ethephon alone at pH 3 at 7 am. Raising ethephon solution pH does not increase harvest effectiveness. Chemical names used: (2-chloroethyl)phosphonic acid (ethephon), naphthalene acetic acid (NAA), 6-benzylaminopurine (BA).
P.W. Simon, V.E. Rubatzky, M.J. Bassett, J.O. Strandberg and J.M. White
Jo Ann Robbins and Patrick P. Moore
During storage for 16 days at 0 or 4.5C or storage for 8 days at 20C, fresh raspberry (Rubus idaeus L. var. idaeus) fruit became darker, less red, and more blue as recorded in L* a* b* CIE coordinates. Cultivars maintained their relative at-harvest ratings throughout storage. Rates of change for cultivars during storage did not differ. Color changes depended on temperature, with rates of change fastest at 20C, especially during the first 4 days. Fruit stored 16 days at OC was more red and less blue than that stored at 4.5C. Maximum color change was reached after 8 days at 0 or 4.5C and after 4 days at 20C.