Abstract
A pink (whitish)-fruited blueberry seedling that appeared in a hybrid highbush blueberry progeny in North Carolina is described. The major anthocyanins (Acy) detected in this seedling were arabinosides and galactosides of delphinidin, petunidin, and malvidin. The pink seedling had the same 15 possible combinations of 5 aglycones and 3 sugars previously reported for the normally blue-fruited cv. Croatan, but in smaller quantities. Total Acy contents of the pink seedling and 9 siblings ranged from 2.5 (pink fruit) to 49 (blue fruit) mg/10-g fruit. Acy content among the different clones was independent of berry pH, acidity (Ac), soluble solids (SS), or SS/Ac ratio. One hundred and seventy-five seedlings in this same progeny were scored for maximum berry color development. The results suggest that Acy expression is dependent on 1 or 2 major genes and that Acy content may be quantitatively inherited. For cultivars whose fruits are normally blue, the commercial use of blue fruit color as the major criterion of marketability (ripeness) may not be valid since color development is not necessarily related to berry ripeness and quality.
Potted plants of 53 highbush and half-high blueberry cultivars were screened for resistance to the blighting phase of mummyberry, Monilinia vaccini-corymbosii under controlled nursery conditions over an 18 day infection period. Significant differences were observed in the susceptibility of different cultivars, with `Bluehaven', `Bluegold', and `Blueray' being among the most susceptible, and `Bluejay', `Jersey', and `Duke' being among the most resistant. Differences were also observed in the latent periods and rate of disease progress which may have a bearing on the severity of the secondary fruit infection phase. Preliminary observations suggest that shoot blighting and fruit infection frequencies are not strongly correlated under high inoculum conditions.
The antioxidant properties of blueberries have been examined only in ripe fruit, although fruit of different maturities are used in processed food products. In this study, highbush blueberry cultivars Bergitta, Bluegold, and Nelson highbush blueberry fruit at different stages of ripeness were examined to characterize differences in oxygen radical absorbing capacity (ORAC) and the phenolic components responsible for ORAC. Underripe fruit at different stages of maturity were also stored at 20 °C for up to 8 days to assess changes in ORAC and phenolic content. Anthocyanin content was substantially higher in fruit of more advanced stages of ripeness. In contrast, the phenolic content and ORAC were lower in the riper fruit. Anthocyanins continued to form during storage, although rate of pigment formation declined after about 4 days. Less anthocyanin pigment was formed in the less ripe fruit. After 8 days of storage, the anthocyanin content of fruit harvested 5% to 50% or 50% to 95% blue exceeded that of ripe fruit. Up to 60% of the total phenolic content could be accounted for by anthocyanins. ORAC was positively correlated with total phenolic content (R 2 = 0.78), but not with anthocyanin content.
Abstract
‘Jersey’ blueberry plants were greenhouse-grown through 1 season with treatments consisting of a factorial combination of 4 soil factors: inoculation with a mycorrhiza-forming fungus; high or low nutrient regime; with or without leachate from a native blueberry soil; and soil porosities corresponding to a clayey, silty, or sandy, and a native blueberry soil, Berryland, as a standard comparison. Although very low in nutrient elements, Berryland soil or its leachate significantly increased plant growth. There was no significant effect on growth from mycorrhizal inoculation at either high or low nutrient levels and only a slight effect from varying the soil free-pore space.
Abstract
GA3 (0, 250, and 500 ppm) was applied at 75% full bloom to blueberry bushes caged with and without bees and to open pollinated bushes. GA3 significantly increased fruit yield per bush, reduced seed wt per fruit, and increased the rate of berry enlargement as compared to fruit not pollinated. No effect was observed on soluble solids and titratable acidity. GA3 appeared to substitute for the effect of pollination and fertilization.
Abstract
Blueberry seedlings were inoculated with Pezizella ericae and grown in peat and pumice potting mix at 3 fertilizer treatments. Fungal inoculation stimulated shoot growth and dry matter production most at 1 application of fertilizer and increased N, S, and Ca shoot concentrations by 17, 47, and 14%, respectively. Increasing application of fertilizer tended to depress mycorrhizal infection levels in inoculated plants.
blueberry ( Vaccinium angustifolium Aiton), highbush blueberry ( Vaccinium corymbosum and their hybrids), and rabbiteye blueberry ( Vaccinium virgatum Aiton). Since the establishment of blueberry breeding programs, genes from various wild blueberry
crosspollinated. Tetraploid forms of V. virgatum were found to be self-sterile but gave a fruit set of 1% to 27% when cross-pollinated with tetraploid V. corymbosum . Vaccinium tenellum Aiton (2x) gave a fruit set below 29% when selfed, but when crossed with
Thekopsora minima inside leaf tissue of overwintering Vaccinium pallidum. Fig. 3. Urediniospores of Thekopsora minima with dense spinules on the lower leaf surface of ( A ) Vaccinium corymbosum , ( B ) Vaccinium tenellum , ( C ) Vaccinium elliottii
genus Vaccinium ( V. angustifolium , V. boreale , V. corymbosum , V. myrtilloides , and V. pallidum ), which have been described taxonomically as being closely related ( Vander Kloet, 1983 ), were collected. For V. angustifolium , four cultivars