The sources of photosynthate for fruit growth in cranberry (Vaccinium macrocarpon Ait.) can be spatially partitioned as new growth, old leaves and woody stems, or adjoining uprights. New growth, l-year-old leaves, or both were removed at the time of fruit set and following fruit set. Removing new growth at the time of fruit set reduced fruit set, fruit count, and yield. Removing old leaves at fruit set generally did not reduce fruit set, fruit count, or yield. Removing both often had an additional effect. Removing new leaves after fruit set did not affect fruit set or count, but did reduce fruit size. Removing old leaves after fruit set did not reduce fruit set, fruit count, or size. These data suggest that new growth is an important source of photosynthate for fruit set.
Teryl R. Roper and John S. Klueh
Catherine C. Neto, Christine A. Dao, Michelle R. Salvas, Wesley R. Autio, and Justine E. Vanden Heuvel
The american cranberry is a fruit grown commercially in a wetland setting in Massachusetts, Wisconsin, New Jersey, Washington, and Oregon ( Eck, 1990 ). The low-growing non-deciduous vine covers bog floors, forming a dense mat. Fruit is borne on
Michael Marcotrigiano and Susan P. McGlew
In an effort to accelerate breeding programs and to study somaclonal variation, a micropropagation system was devised for cranberries (Vaccinium macrocarpon). Using a factorial design, explants taken from greenhouse grown plants were placed on Anderson's medium containing different concentrations of 2ip' GA3, and IBA, with 4 cultivars tested over 3 subcultures. In other experiments, explant source, macro and micro salt formulations, and rooting treatments, were studied. Optimal multiplication and shoot quality occurred when single node explants taken from greenhouse grown plants were placed on Anderson's media containing 150 uM 2iP, 1.0 uM IBA and no GA3. Histological examinations indicate that initial response is axillary bud proliferation but upon subculture adventitious shoot formation may be possible. Proliferated shoots could be rooted ex vitro in plug trays under plastic tents and without hormone treatments. Optimal rooting occurred under high light conditions in a 1:1 (v:v) peat:sand mix. Plants were easily transplanted into the field in spring and will be evaluated by comparison to conventionally propagated material.
Elissa M. Novy and Nicholi Vorsa
Accurate estimates of yield and yield components for parental selection would facilitate cranberry breeding efforts. A study was designed to obtain value estimates for traits related to yield. Ten commonly-cultivated varieties grown in a replicated planting, were evaluated in 1991 and 1992 for fruit yield per unit area (FY), average berry weight (BW) and number of berries per unit area, or berry concentration (BC). Averaged over all varieties, FY was significantly greater in 1992. BC was responsible for higher yields in 1992. Regression analysis revealed that BC accounted for more of the variation in FY than did BW in both years. BW accounted for some variation, however, in 1991 when FY was lower. Varieties differed significantly in FY, BW and BC. Hybrid varieties bad significantly greater FY and BW than wild selections. Variation for yield components exists among varieties tested, suggesting genetic gain is possible for yield with additional breeding efforts. In particular, greater fruit set should be emphasized as a breeding objective.
Joan R. Davenport and Daniel E. Schiffhauer
Surface sand application to cranberry (Vaccinium macrocarpon Ait.) is commonly practiced for a combination of vine and insect management. However, the efficacy of sanding on crop production has been poorly documented. This study determined the effect of three rates of sand application using a barge sanding technique on two different cultivars—`Early Black' and `Stevens'. Beds were sanded to a depth of 0, 1.3, or 2.5 cm in November and monitored at the end of the following three growing seasons for yield, berry weight, and upright distribution. The 2.5-cm sanding rate adversely affected yield in `Early Black' during the first two growing seasons. In `Stevens' yields were not reduced until the third season and then only by the 2.5-cm rate. Although the 2.5-cm sanding rate increased vegetative upright density in both cultivars in the first growing season, yield and number of fruiting uprights were not significantly influenced the next year. Application of 1.3 cm of sand could improve insect pest management without negatively impacting yields of `Early Black' and `Stevens'.
Lisa J. Rowland, Anik L. Dhanaraj, James J. Polashock, and Rajeev Arora
Expressed sequence tag-polymerase chain reaction (EST-PCR) markers for DNA fingerprinting and mapping in blueberry (Vaccinium sp.) had previously been developed from expressed sequence tags (ESTs) produced from a cDNA library, derived from RNA from floral buds of cold acclimated plants. Because EST-PCR markers are derived from gene coding regions, they are more likely to be conserved across populations and species than markers derived from random regions of DNA, such as randomly amplified polymorphic DNA (RAPD) or amplified fragment length polymorphism (AFLP) markers. In this study, we tested whether many of the EST-PCR primer pairs developed for blueberry are capable of amplifying DNA fragments in other members of the family Ericaceae. In addition, we cloned and sequenced a selection of 13 EST-PCR fragments to determine if they showed homology to the original blueberry cDNA clones from which the EST-PCR primer pairs were derived. Closely related cranberry genotypes (two wild selections of V. oxycoccus L. and two cultivars of V. macrocarpon Aiton, `Early Black' and `Stevens') and more distantly related rhododendron genotypes (one wild selection each of Rhododendron arboreum Marsh, R. maximum L., and R. ponticum L. and three complex species hybrids, `Sonata', `Grumpy Yellow', and `Roseum elegans') were used. Of 26 primer pairs tested in cranberry, 23 (89%) resulted in successful amplification and eight of those (35%) amplified polymorphic fragments among the cranberry genotypes. Of 39 primer pairs tested in rhododendron, 29 (74%) resulted in successful amplification and 21 of those (72%) amplified polymorphic fragments among the rhododendron genotypes. Approximately 50% of the 13 sequenced EST-PCR fragments were found to be homologous to the original blueberry cDNA clones. These markers should be useful for DNA fingerprinting, mapping, and assessing genetic diversity within cranberry and rhododendron species. The markers which are shown to be homologous to the blueberry cDNA clones by DNA sequencing should also be useful for comparative mapping and genetic diversity studies between some genera of the family Ericaceae.
Eric Hanson, Carolyn DeMoranville, Benjamin Little, David McArthur, Jacques Painchaud, Kim Patten, Teryl Roper, Nicholi Vorsa, and David Yarborough
Since up to 2.4 m (8 ft) of water may be applied annually to cranberry beds for various production purposes, water quality can alter soil chemical properties and potentially affect plant health. Many cranberry plantings have recently been developed in nontraditional production regions and on atypical sites, wherechemical properties of the available water may differ from those in cranberry sites in the traditional production regions. Water currently being used for cranberry production was sampled from farms in most major production regions to characterize its chemical characteristics. High alkalinity in many samples was a concern, since alkalinity can increase soil pH above the desired level for cranberries. Total soluble salt concentrations and sodium adsorption ratios were seldom high enough to be of concern. Water samples from long-established plantings were lower in alkalinity, pH, and soluble salt concentrations than samples from newer plantings without production histories.
J. R. Davenport and C. J. DeMoranville
Like many fruit crops, the difference between vegetative and reproductive production in cranberry is strongly influenced by nitrogen supply, as is fruit quality. However, the optimal supply for this crop has not been established. Further, there have been mixed results on whether or not cranberry can metabolize nitrate nitrogen. Within the past 6 years there has been an upsurgence in research on cranberry nitrogen nutrition and it has started to provide answers to some of these unknowns. Results from the lab of L. Peterson (U Wi - Madison) have shown that cranberry will take up nitrate nitrogen, however the uptake is minimal unless ammonium nitrogen is present. The work from Peterson's lab has also shown that there is some nitrate reductase activity in cranberry leaves, albeit at very low levels. Work that we have conducted and work by J. Hart's group (OSU) have been the basis for establishing optimal nitrogen rates and timings for cranberry in the different growing areas in North America. Overall, the work from these different groups has shown that except in extreme situations, 22 - 33 kg N/ha is optimal for cranberry production. However, timing of application varies widely due to weather conditions in the different growing areas.
Piero A. Spada, Beth Ann A. Workmaster, and Kevin R. Kosola
Cranberry (Vaccinium macrocarpon) plants colonized with ericoid mycorrhizal fungi are capable of utilizing organic nitrogen sources that are unavailable to non-mycorrhizal plants. Despite the importance of mycorrhizal colonization in the nitrogen nutrition of wild cranberry, almost all measurements of cranberry nitrogen uptake and assimilation have been carried out with non-mycorrhizal plants. We have found that cranberry can be inoculated directly in solution culture. We cultured the ericoid mycorrhizal fungus Hymenoscyphusericaein liquid culture, harvested and rinsed hyphae, and added ≈200 mg fresh weight hyphae per rooted cranberry cutting (cv. Stevens) growing in a modified Johnson's solution. After 6 weeks, newly developed roots were most heavily colonized. We examined the effects of NH4 + concentration (5, 10, 20, 50, 100, and 500 μm NH4 +) in solution on colonization rates. Colonization (% root length) increased with increasing ammonium concentration in solution, with maximum colonization at 50 and 100 μm NH4 +; colonization was much lower at 500 μm NH4 +. Cranberry inoculated with H. ericaein solution culture will be used for analysis of the effects of mycorrhizal colonization on uptake kinetics of NH4 +, NO3 -, and amino acids.
Brent H. McCown and Eric L. Zeldin
1 Gottschalk Distinguished Professor, E-mail ad dress: email@example.com 2 Researcher. This research was funded by the Wisconsin Cranberry Board, Ocean Spray Cranberries, The Gottschalk Endowment, and the Univ. of Wisconsin College