We have characterized the seasonal accumulation of transcripts and proteins in peach (Prunuspersica), particularly a 60 kDa dehydrin (PCA60; PpDhn1). Recently, we have isolated another dehydrin gene (PpDhn2). The present report compares the structural organization of the two dehydrin genes, their promoters, and the response of the genes to temperature, photoperiod, and water deficit. Trees were exposed for 3 or 5 weeks to either short day (SD) or long day (LD) photoperiods at either 25 or 5 °C. Additional experiments exposed trees to a period of water deficit followed by recovery. Transcript abundance of both genes, as assessed by RT-PCR, was determined, in response to the different photoperiods and temperatures as well as a prolonged SD/5 °C regime, from monthly-collected field samples, and trees subjected to water deficit. Results indicated that water deficit increased transcript abundance of both genes, but their abundance differed dramatically in response to low temperature and seasonal cues. Surprisingly, neither gene exhibited a significant elevation in transcript abundance in response to SD conditions. The lack of response of PpDhn1to SD is problematical given the observation that transcript levels in field-collected samples begin to increase substantially in September, prior to the onset of cold temperatures. Analysis of the promoter regions and cis-acting elements suggest that ABA may play an important role in seasonal expression, interacting with photoperiod in field conditions. Two CRT/DRE elements are present in the promoter region of PpDhn1, but absent in the promoter of PpDhn2.
Strawberry (Fragaria × Anaassa cv. Tribute) plants were planted in 15 cm standard pots filled with overburden soils from three West Virginia surface mine sites. Initial pH levels were 6.5, 4.4, and 3.6. Prior to planting pH levels were adjusted with CaCO3 to 6.5-6.7 in each soil. Each soil was amended by mixing in 60.85 g/pot (62.5 dry kg/ha) of sewage sludge, Sudan-sorghum hybrid green manure crop, hardwood residues, or unamended. A dry fertilizer (.10-.045-,089, N-P-K) was also mixed into the soil at a rate of 0.5 g/pot (454 kg/ha). Plants were grown from 3-6 to 10-16, 1992, on which date harvests and measurements were performed. The sludge treatments significantly increased fresh and dry weight accumulation, number of leaves, leaf area, and number of runners per plant above that of the control plants. The hardwood residues amendment delayed first date of ripe fruit and decreased average fruit fresh weight in one of the soils. Hardwood residues also decreased leaf number in another soil. The pH levels were raised to 6.8-7.3 by the sludge in all soils and remained at or near these values during the growing period.
Experiments were conducted on the Easter lily cultivars (Lilium longiflorum thunb.) Ace and Nellie White over a 4-year period to compare ancymidol bulb dips to media drenches and foliar spray applications. Several bulb dip concentrations and durations were used. ‘Ace’ plants responded more than ‘Nellie White’ plants to bulb dips, primarily because of more natural vigorous growth of ‘Ace’ plants. A 1-hr dip at 33 ppm gave adequate height control, but flowering was delayed. Reliance on bulb dips to achieve optimum height control may be questionable because ancymidol must be applied before one is certain excessive height will be a problem. Chemical name used: α-cyclopropyl-α-(4-methoxyphenyl)-5-pyrimidinemethanol (ancymidol).
Methanol extracts of fresh tissues of ‘Mazzard’ (Prunus avium L.) and ‘Mahaleb’ (P. mahaleb L.) were examined for phenolic composition. The 2 sweet cherry rootstocks differed in 3 phenolic groups; phenolic acids, coumarins, and flavonoids. ‘Mazzard’ contained 5 acids; p-coumaric, o-coumaric, caffeic, p-coumarylquinic and chlorogenic, whereas ‘Mahaleb’ contained mostly o-coumaric acid. ‘Mahaleb’ tissues were rich in coumarin and herniarin, but these were absent in ‘Mazzard’. Three flavonoids; dihydrowogonin, kaempferol and quercetin, were found in ‘Mazzard’. ‘Mahaleb’ contained only kaempferol. These differences in phenolic composition between the 2 rootstocks seemed related to graft-incompatibility.
., 2006 ). Pine bark has been observed to be a suitable medium for plant growth ( Pokorny et al., 1986 ), especially in southern nurseries, and is accepted as the primary component of most soilless substrates in container production ( Bilderback et al
objective of this research was to determine flurprimidol dissipation rates from a flurprimidol-coated granule and to compare directly the movement of flurprimidol in sand, pine bark, and hardwood bark. Materials and Methods Greenhouse studies were conducted
the quality of the underlying soil. Oliveira and Merwin (2001) reported reduced soil bulk density, increased infiltration and porosity, but no change in water-holding capacity in a silty clay loam under deep bark mulch (15 cm reapplied every 3 years
Composted organic wastes have the potential to substitute for peat and bark as components of the growth substrates in containerized plant production systems ( Carlile, 2008 ; Clark and Cavigelli, 2005 ; Estévez-Schwarz et al., 2009 ; Fitzpatrick
.1536) between optimal production K (Ψ = −75 hPa) and measured K s for bark-based substrates ( Fields, 2017 ). This is due to K being a limiting factor for water uptake by roots in soilless substrates ( Raviv et al., 1999 ) and field soils ( Campbell and