Cecil Stushnoff

• PhD
• Colorado State University

Using reclaimed water to irrigate food crops presents an exposure pathway for persistent organic contaminants like perfluoroalkyl acids (PFAAs) to enter the human food chain. This greenhouse study used reclaimed water augmented with varying concentrations (0.2-40 µg/L) of PFAAs, including perfluorocarboxylates (C3F7COO- to C8F17COO-) and perfluoros...

Secondary metabolites in potato have been reported to possess bioactive properties, including growth inhibition of cancer cells. Because potatoes are widely consumed globally, potential health benefits may have broad application. Thus we investigated growth inhibition of HT-29 colon cancer cell cultures by extracts from 13 diverse genetic breeding...

While there is ample evidence that woody plant dormant bud survival following cryopreservation depends upon inherent capacity for cold hardiness and desiccation tolerance, several additional variables may contribute to success or failure including; sampling time and interval, pre-freezing and cryopreservation protocols. Much less is known about the...

Background: Twelve Colorado-grown specialty potato clones were evaluated for total phenolic content, antioxidant activity and ascorbic acid content at harvest and after 2, 4, 6 and 7 months cold storage at 4 °C. Potato clones were categorized as pigmented ('CO97226-2R/R', 'CO99364-3R/R', 'CO97215-2P/P', 'CO97216-3P/P', 'CO97227-2P/P', 'CO97222-1R/...

Our previous research revealed that two solid pigmented skin and flesh selections, a red selection (POTR) and a purple selection (POTP) inhibited HT-29 colon cancer cells in culture when harvested as immature tubers. Potentially bioactive classes of metabolites have been found in potato by others, to induce antiproliferative activity in cancer cell...

(Malus x domestica Borkh. cv Braeburn) apples grown at Royal City, WA, USA under biologically enhanced organic (BEO) methods with nutrient and microbial enhancements were compared with apples produced using conventional methods. Apples from the outer and inner tree canopies were evaluated for antioxidant capacity, soluble solids content (SSC), shel...

Background and Aims: Spring freeze events can result in substantial grapevine yield losses in many parts of the world. Understanding vine responses following early spring freeze events will aid in the development of decision support systems for vineyards damaged by freezing temperatures. Methods and Results: The date of budburst of spur-pruned Char...

While greenhouse production of minitubers has markedly improved production of disease free seed, minituber dormancy can be an issue. This study tested application of abscisic acid (ABA), ethylene (E), gibberellic acid (GA) and the combination of E+GA on release of dormancy in potato minitubers, sprout development, and subsequent effects on field pl...

Sensory properties, quality attributes (color, texture, total soluble solids, dry weight) and indicators of secondary metabolites (total phenolic compounds, radical scavenging capacity) of eight specialty leafy greens were evaluated in this study. Because of its commercial availability and consumer familiarity, red iceberg lettuce was chosen as the...

Differential thermal analysis is used to detect low-temperature exotherms, the nucleation of supercooled aqueous fractions, indicative of lethal freezing temperature in certain plant tissues. However, in plant tissues that do not supercool at low temperatures, there has been no analytical technique to detect events during lethal freezing. Simultane...

Callus cultures of strawberry cv. Redcoat (2n = 8x = 56) initiated from greenhouse and in vitro leaf explants were examined at various culture periods for morphogenic response, changes in nuclear DNA content, and isozyme banding patterns of four enzymes. The flow cytometric analysis of nuclear DNA content revealed the occurrence of polyploid and an...

Flower-bud dehardening of saskatoon-berry (Amelanchier alnifolia Nutt. ‘Smoky’ and ‘Pembina’) was studied under natural and controlled conditions. Flower buds were hardy to −45 °C until the middle of March, after which hardiness gradually declined to −12 °C by the beginning of May. Petal expansion was associated with a loss of hardiness, even thoug...

Export Date: 18 October 2014

Tomatoes (Solanum lycopersicum L.) are widely consumed and well known for their health benefits, many of which have been associated with the high levels of antioxidants present in tomatoes. With a growing interest in local and organic foods, it would be helpful to determine whether farmers could naturally improve the quality and antioxidant content...

Leafy vegetables are particularly good sources of bioactive compounds since in addition to being principal photosynthesis sites, leaves are major accrual areas of metabolites. Plants synthesize various secondary metabolites for functions such as defense mechanisms against insects, pathogens, and photooxidation. Effects of these compounds on human h...

Association between human health and bioactive compounds of leafy greens has been the focus of several academic and industry studies in recent years. Phenolic compounds, the largest group of plant phytochemicals, are of great importance both in plant physiology and human nutrition. Plants use these compounds as defense mechanisms against insects, p...

The molecular mechanisms responsible for selenium (Se) tolerance and hyperaccumulation were studied in the Se hyperaccumulator Stanleya pinnata (Brassicaceae) by comparing it with the related secondary Se accumulator Stanleya albescens using a combination of physiological, structural, genomic, and biochemical approaches. S. pinnata accumulated 3.6-...

Butterhead, crisphead, green leaf, red leaf, and romaine types of lettuce (Lactuca sativa L.) are all commonly available in U.S. markets. Sensory properties of lettuce may vary in response to environmental factors that often fluctuate widely throughout the growing season. Bitterness is generally thought to increase in lettuce grown at higher temper...

Anthocyanin content of potato tubers is a trait that is attracting increasing attention as the potential nutritional benefits of this class of compound become apparent. However, our understanding of potato tuber anthocyanin accumulation is not complete. The aim of this study was to use a potato microarray to investigate gene expression patterns ass...

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Fruits of the date palm are very commonly consumed in many parts of the world and are a vital component of the diet. Date fruits were found to be a good source of antioxidant components. The antioxidant properties of date fruits vary depending on their content of phenolic components, vitamin C and flavonoids. Fruits of ten cultivars from USA and fr...

Antioxidant properties and quality attributes were evaluated for 10 melon (Cucumis melo L.) cultivars grown under conventional and certified organic conditions in a 2-year field study. Differences among cultivars, produced either by conventional or organic methods, contributed the largest sources of variation in antioxidant properties. A 2.1-to 2.2...

Effects of freeze-dried potato powder, prepared from baked potato with skin and incorporated into a purified diet, on the post-initiation phase of chemically induced breast carcinogenesis in rats, were evaluated for both dose dependence and variation in anticancer activity among cultivars. Associations among anticancer activity, select phytochemica...

Experiments reported herein tested the hypothesis that cultivars of apple (Malus domestica Borkh.) would demonstrate anticancer activity in vivo as predicted by in vitro measures. Freeze dried powders of Red Delicious (RD), Fuji (FJ), Golden Delicious (GD), and Granny Smith (GS) apple cultivars were evaluated. Significant differences were noted amo...

Consumers have become increasingly aware of potential health benefits from diets rich in fruits and vegetables. While potato has not yet surfaced as a headline-grabber in this respect, there is increasing evidence that some genotypes may possess health attributes that warrant attention. Plant breeders rely on germplasm biodiversity to advance their...

Fresh apple (Malus spp.) juice potentially contains similar phenolic compounds as the fruits from which it is derived, although some phenolic compounds may be lost or changed in quality during juice production, especially during pasteurization, which is necessary because apple juice is a chemically and microbiologically sensitive product. Juice was...

Total phenolic content (TPC) and antioxidant capacity of lettuce were evaluated using the Folin–Ciocalteu method and DPPH assay, respectively, on 25 cultivars of lettuce, including leaf, romaine, crisphead, and butterhead types, cultivated over two harvest periods. Leaf lettuce possessed the highest TPC and highest DPPH scavenging ability, followed...

Cultivar response to storage temperature is a major determinant of potato (Solanum tuberosum L.) tuber dormancy, storage life and soluble sugar content. Considerable genetic variability for storage traits is extant among cultivars, thus to optimize economic returns the release of new potato introductions for grower production should ideally be conc...

The influence of storage temperature and length of time in storage on anthocyanin tuber concentration were investigated in seven potato genotypes. These genotypes were cultivars `All Blue' and `Yukon Gold' plus five selections that were various skin/flesh color types of red/red, purple/purple, white/yellow, and two red/yellow types. The red, blue,...

The effect of photoperiod and temperature on growth and induction and development of frost hardiness in cloudberry (Rubus chamaemorus L.) was examined in two experiments. The photoperiods were 8, 12 or 24 h and the temperatures were 18, 15, 12, 9, 4, 3, –3 or –4°C depending on the experiment. The level of hardiness was expressed as LT66 or LT50 (th...

The effect of ascorbic acid applied by 2 hydrocooling methods on chemical and physical properties of‘Waldmann's’dark green leaf lettuce (Lactuca sativa L.) during cold storage was evaluated. Lettuce was immersed (in 1% ascorbic acid or tap water) or sprayed (with 1% ascorbic acid or tap water) or left untreated (control). Treatment solutions for im...

Phlorizin is known for its role in reducing glucotoxicity and has a long history of use in diabetes research. In addition, its contribution to the pool of total phenolics adds to the overall health benefits attributed to fruit. Phlorizin is limited to Rosaceae family plants, of which apple comprises its current commercial source; however, limited i...

Petunia xhybrida (Hook) Vilm. cv. Mitchell was transformed with an E. coli gene encoding mannitol-1-phosphate dehydrogenase (mtlD). Four plant lines that grew on kanamycin and contained the mtlD transgene were identified. Two of these lines contained high levels of mannitol [high-mannitol lines M3 and M8; mean mannitol = 3.39 μmol·g-1 dry weight (D...

Petunia xhybrida (Hook) Vilm. cv. Mitchell was transformed with an E. coli gene encoding mannitol-1-phosphate dehydrogenase (mtlD). Four plant lines that grew on kanamycin and contained the mtlD transgene were identified. Two of these lines contained high levels of mannitol [high-mannitol lines M3 and M8; mean mannitol = 3.39 mu mol(.)g(-1) dry wei...

Phlorizin is known for its role in reducing glucotoxicity and has a long history of use in diabetes research. In addition, its contribution to the pool of total phenolics adds to the overall health benefits attributed to fruit. Phlorizin is limited to Rosaceae family plants, of which apple comprises its current commercial source; however, limited i...

Extracts from Petunia × hybrida plants, which had been subjected to cold pretreatment to induce chilling tolerance, were analyzed for specific phenolic acids, such as gentisic acid, and assessed for their antioxidant capacity by their ability to reduce (decolorize) the 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid)diammonium salt radical (AB...

Twelve-week-old Malus seedlings were induced to cold harden by exposure to low temperature and freezing environments. The effectiveness of induced acclimation by exposure to stimuli such as low temperature (3 to 5°C), frequency of exposure to freezing temperatures (-3°C), storage time before and after induction and the effects of different screenin...

Previous studies of plant tolerance to low temperature have focused primarily on the cold acclimation response, the process by which plants increase their tolerance to freezing in response to low nonfreezing temperatures, while studies on the deacclimation process have been largely neglected. In some plants, cold acclimation is accompanied by an in...

Salinity, drought and temperature frequently limit crop productivity. Transgenic Petunia ×hybrida cv. Mitchell with altered endogenous raffinose family oligosaccharides (RFO) due to over-expression (sense) or under-expression (antisense) of the tomato α-galactosidase gene show that antisense increases in RFO are associated with greater tolerance to...

Basil (Ocimum basilicum L.) is used in traditional medicine, as a culinary herb and a well-known source of flavouring principles. Total antioxidant activity in 23 Iranian basil accessions was determined as Trolox equivalent antioxidant capacity (TEAC). Total phenolic contents were determined using a spectrophotometric technique, based on the Folin-...

Previous studies of plant cold hardiness have focused mainly on the cold acclimation response, while studies on the deacclimation process have been limited. Alpha-galactosidase a key catabolic enzyme of the raffinose family oligosaccharides (RFO), cleaves the terminal-linked moiety from galactose-containing oligosaccha- rides. A cDNA clone petgal,...

Alpha-galactosidase (alpha-Gal; EC 3.2.1.22) is involved in many aspects of plant metabolism, including hydrolysis of the alpha-1,6 linkage of raffinose oligosaccharides during deacclimation. To examine the relationship between endogenous sugars and freezing stress, the expression of alpha-Gal was modified in transgenic petunia (Petunia x hybrida c...

Tomato (Lycopersicon esculentum Mill.), a potent source of antioxidants in the diet, is characterized by remarkable genetic biodiversity, especially in fruit size and color. Horticultural practices and breeding efforts hold the potential to enhance antioxidant content in tomato fruit, but which antioxidants are most important? Lycopene content, tot...

Embryonic axes of Citrus sinensis L. were successfully cryopreserved. While fully hydrated unfrozen axes germinated 100%, survival decreased as axes water content dropped, and total loss of viability was observed when the water content dropped to 0.04 and 0.10 mg H2O/mg dry mass, for axes without and with sucrose preculture, respectively. Fully hyd...

Regular consumption of fruit and vegetables containing naturally occurring antioxidants has been recommended to intervene in the onset and development of lifestyle diseases, such as cancer and cardiovascular diseases. While apples have long been recognized as beneficial to human health, data on antioxidant content and radical scavenging activity, a...

NO information is available regarding endogenous soluble carbohydrate accumulation in buffalograss [Buchloe dactyloides (Nutt.) Engelm.] during cold acclimation. The objective of this study was to determine composition of soluble carbohydrates and their relationship to freezing tolerance in two buffalograss cultivars, 609 and NE 91-118, with differ...

Changes in metabolism that accompany cold acclimation and deacclimation, such as increasing levels of raffinose family oligosacharides (RFO) during cold acclimation demonstrated in several woody species, are of interest in a search for genetic control of environmental adaptation by cold-hardy woody plants. This study examined the relationship of te...

Seasonal change in cold hardiness has frequently been associated with metabolic induction of osmolytes that may play a role in acclimation to low temperatures in cool season crop plants. The present research was aimed to examine the association of common endogenous sugars with cold hardiness in acclimated and non-acclimated plants of winter-hardy a...

This study describes the development of a highly repeatable cold screening procedure for lentil (Lens culinaris Medik.) using controlled conditions which involve first, acclimation of the plants at the vegetative stage in a growth chamber and second, freeze testing in a freeze chamber. The seeds were first germinated in Petri dishes and then plante...

Unlike cold-hardy apple germplasm, dormant vegetative buds from cold-tender accessions require stabilization of meristematic tissue to protect against injury during desiccation and cryopreservation. Dormant buds of six apple cultivars [Malus sylvestris (L.) Mill. var. domestica (Borkh.) Mansf. 'Cox's Orange Pippin', 'Einshemer', 'Golden Delicious',...

The influence of plant size on recovery following defoliation of `Tainung 1' papaya was used to study the role of respiratory sink size relative to photosynthetic surface area and the carbohydrate pool size available for remobilization. Defoliated (D) plants at three different ages: oldest, 24 weeks posttransplant (PT), supporting ≈8 weeks of fruit...

Clonally propagated crops, unlike seed-propagated crops, require intense and costly maintenance, generally in ex situ field gene banks. Consequently, large germplasm collections of tree species especially, are difficult to conserve in a well-replicated fashion and are vulnerable to damage from environmental stresses. Accordingly, long-term storage...

Purpose: First, to investigate the role of sucrose in stabilizing protein structure (as measured by changes in the amide I band of lysozyme) caused by dehydration encountered during lyophilization. Second, to demonstrate the utility of internal reflection spectroscopy as a tool for conducting controlled lyophilization experiments. Methods: A cus...

Economically, citrus is the second most-important fruit crop grown worldwide; thus germplasm conservation of commercial cultivars, as well as of wild relatives, is essential. Presently, citrus germplasm has been conserved mainly in field genebanks. This approach is helpful; however, it is costly, exposes germplasm to climatic and biological hazards...

Tobacco plants (Nicotiana tabacum L.) were transformed with a mannitol-1-phosphate dehydrogenase gene resulting in mannitol accumulation. Experiments were conducted to determine whether mannitol provides salt and/or drought stress protection through osmotic adjustment. Non-stressed transgenic plants were 20–25% smaller than non-stressed, non-transf...

Cold hardy woody plant species possess remarkable capacity to acclimate and survive seasonal stresses. While growth and development are normally most active under fully hydrated conditions, plant tissues are also least adapted to cope with environmental stresses in the hydrated state. Reduction in moisture content must be accompanied by endogenous...

Various carbohydrates have been shown to be associated with stress tolerance in some plant species. Specifically, the content of soluble sugars have been correlated with desiccation tolerance and winter hardiness. We have previously demonstrated that radicles of cucumber seed become progressively more sensitive to chilling injury during the early s...

The USDA–ARS germplasm collection of cold-hardy Vitis held at the Plant Genetic Resources Unit, Geneva, N.Y., has over 1300 clonal accessions maintained as field-grown vines. Security back-up using field-grown or potted vines at remote sites or via in vitro methods is costly. Cryopreservation offers a safe, cost-effective alternative. While we rout...

Cold hardiness and endogenous levels of soluble sugars were monitored during the dormant season for Chardonnay and Riesling (Vitis vinifera L) dormant buds and stem cortical tissues. Endogenous levels of glucose, fructose, raffinose, and stachyose were strongly associated with cold hardening, increasing from the onset of cold acclimation in August...

The response of Vitis vinifera cultivars to methanol was investigated at the Orchard Mesa Research Center in Grand Junction, Colorado. Sublethal methanol doses, based on visual observations, were 90% for leaves and 100% for trunks. The accumulation of total soluble solids (TSS) in berries was also monitored weekly until harvest. There was no signif...

Apples are grown in virtually all temperate climates and with modern storage and transportation are found in every country, essentially year-round. The origin of modern cultivars can be traced to a few centers where genetic diversity flourished because of environmental conditions conducive to the evolution and sustenance of diverse genotypes. Globa...

Spectral changes for a 49.4 mg/ml solution of lysozyme with 10% sucrose in D2O were followed in real time during the course of lyophilization by using infrared spectroscopy. A low-temperature, single reflection, horizontal, attenuated total reflection (SRHATR) accessory, connected to a lyophilizer provided the capability to probe the effects of deh...

The response of grapevines to methanol was investigated at the Orchard Mesa Research Center in Grand Junction, CO. Optimum sublethal methanol dose levels, based on visual assessments, were 90% for leaves and 100% for trunks for 10 cultivars. Total soluble sugars (TSS) of the berries, monitored every week until harvest, showed significant difference...

Cryopreservation of mature dormant vegetative buds is a useful method to preserve germplasm of a large number of cold hardy apple cultivars. However, cold tender cultivars have proven to be much more difficult to cryopreserve. Eight cultivars were harvested in September 1993 at Geneva, NY before developing cold hardiness naturally. The twigs were e...

Strawberry plantlets, regenerated from leaf disks, were used as a model system to study the effect of high concentrations of sugars and dehydration on survival during cryopreservation. After cold acclimation, plantlets imbibed for 3 days (one day each) in 0.5, 0.7 and 1.2 M sucrose and (1.0M sucrose + 0.2M raffinose) and desiccated to 25 % moisture...

Strawberry cultivars, Redcoat and Veestar, propagated by meristem culture (MC), callus culture (CC) and direct shoot regeneration (DR) from leaf disks were compared for their vegetative and reproductive characters with standard runner (SR) propagated plants under field conditions. In the planting year, in vitro propagated plants of both cultivars h...

Water loss during lyophilization of a 49.4 mg/mL solution of lysozyme in D2O was studied with ir spectroscopy using a low-temperature, single reflection, horizontal, attenuated, total reflectance accessory. Four regions of water loss were identified and assignable to different forms of bound water. The amide I band begins to shift to higher frequen...

When acclimated strawberry plants (Fragaria × ananassa Duch. ’Redcoat’) from the field were placed in a programmable freezer, mother strawberry crowns were as hardy or hardier than daughter crowns when frozen to −11 °C. However, under field conditions, daughter plants expressed consistently greater hardiness than mother plants. Mulching had no effe...

Differential scanning calorimetry was used to study the effects of sucrose and dehydration on biophysical aspects during cryopreservation of strawberry plantlets, regenerated from leaf disks. Plantlets were encapsulated in alginate beads, soaked 24, 48, 72 and 96 hours in sucrose solutions (0 to 2.0 M) and dehydrated. Imbibition in 1.0 - 2.0 M sucr...

Dormant buds of 64 apple accessions from the National Germplasm Repository (NGR), Geneva, NY were cryopreserved at the National Seed Storage Laboratory (NSSL), Fort Collins, Co. Initial tests after 1 mon, 1, 2, and 3 years of LN 2 storage showed no decline in viability. Storage of 16 cultivars (1988/89 and 1989/90 dormant seasons) with a broad rang...

Acclimation and de-acclimation of woody plants is correlated with endogenous levels of raffinose family oligosaccharides (RFO), but not to total sugars or other oligosaccharides. Synthesis begins at the onset of cold acclimation and reaches a maximum in mid-winter at peak hardiness. RFO levels decline as cortical stem tissues de-acclimate. Exposure...

Low temperature and frost are among the most important environmental constraints limiting the productivity and distribution of plants on the earth’s surface. Although future climatic changes are difficult to predict with certainty, it is clear that, if global warming increases the frequency and severity of mid- and late-winter fluctuations, especia...

The relationship between freezable water and cold hardiness during acclimation was studied using vegetative buds from several apple (Malus domestica Borkh) cultivars and from one saskatoonberry (Amelanchier alnifolia Nutt. cv. Smoky) cultivar. According to leakage data and visual assessments of cortical browning, vegetative buds of all cultivars we...

Cryopreservation of woody-plant, dormant buds may provide cost-effective, long-term, back-up conservation of germplasm for vegetatively propagated crops that are presently maintained as trees in field gene banks. Dormant buds can be recovered quickly by grafting to dwarfing rootstocks, thus producing flowers for breeding purposes, with minimum pote...

Woody plants can be induced to cold-acclimate by exposure to sublethal low temperatures, but only after the onset of vegetative maturity. We monitored seven woody plant taxa, at monthly intervals, to determine the date of vegetative maturity, freeze-killing temperature, cell membrane electrolyte leakage, and the quantity and diversity of endogenous...

Plant survival, bloom response and fruit yield following fall application of a plastic row cover, plastic row cover covered with barley straw, conventional straw, and no cover were compared for two strawberry cultivars, Fragaria × ananassa Duch. Bounty and Hecker. Response was highly dependent on weather conditions. Plastic row cover + barley straw...

The effect of plant growth regulator concentrations and ageing of callus on the extent and nature of variation among callus culture regenerants of strawberry (Fragaria ananassa) cv. Redcoat was examined. Plants regenerated from callus culture had reduced plant vigour, shorter petiole length and smaller leaf size, but more leaves and runners under g...

Aqueous fractions in dormant buds of Amelanchier alnifolia Nutt. `Smoky', may exist either as liquid, ice or glass phases depending on the temperature history and the water content of the tissue. Phase diagrams for these states were constructed from differential scanning calorimetry (DSC) freezing and warming scans. The diagrams show that glass tra...

Polyacrylamide gel electrophoresis (PAGE) was used for analysis of isozyme banding patterns of leucine aminopeptidase (LAP), phosphoglucomutase (PGM), phosphoglucoisomerase (PGI), esterase (EST) and 6-phosphogluconate dehydrogenase (6-PGD) in strawberry leaves. The extracts prepared from young leaf tissues using polytron homogenization and an extra...

Plant regeneration was studied using immature leaf explants taken from in vitro shoots and greenhouse grown plants of the strawberry cv. Redcoat. Both types of explants formed callus and multiple shoots at various frequencies in the presence of benzyladenine (BA) and 2,4-dichlorophenoxyacetic acid (2,4-D) at different concentrations. Highest shoot...

An efficient genetic transformation protocol has been developed for strawberry cv. Redcoat using Agrobacterium tumefadens. The protocol relies on a high frequency (84%) shoot regeneration system from leaf disks. The leaf disks were inoculated with a non-oncogenic Agrobacterium tumefadens strain MP90 carrying a binary vector plasmid pBI121 which con...

Cryopreservation of dormant buds has potential to provide back-up conservation of vegetatively propagated genetic resources for fruit crop species. This system may be useful where clonal integrity must be maintained and where it is desirable to rapidly recover plants with flowers for crossing purposes. In 1988, a pilot project involving the Nationa...

There is need for backup storage of clonally propagated plant cultivars of numerous taxa. Initial tests, using a protocol developed for dormant apple buds that includes desiccation and slow freezing prior to immersion in liquid nitrogen (-196 C), was not effective with `Valiant' grape. Accordingly, replicates of V. vinifera `Riesling', V. riparia,...

Transformed calli and shoots of strawberry (Fragaria × ananassa Duch.) cv. Redcoat were obtained using Agrobacterium tumefaciens carrying plasmid pB1121. Inoculated leaf explants produced transgenic calli at a frequency of 3% on selection medium containing 50 μg/ml kanamycin. Twenty per cent of selected caili regenerated, giving rise to transgenic...

An efficient and reproducible method of direct shoot regeneration from leaf disks in strawberry ( Fragaria × ananassa cv. Redcoat) has been developed. The influence of hormone concentration, light intensity, orientation of leaf disk, and age of explant source on shoot regeneration was examined. Regeneration of leaf disks reached 94%, with an averag...

Onset of vegetative maturity and its relationship to cold acclimation was studied in the saskatoon berry (Amelanchier alnifolia Nutt.). Red-osier dogwood (Cornus stolonifera Michx.) and Rescue crabapple (Malus domestica × baccata) were also included in the study for comparison. The onset of vegetative maturity was on 29 May 1985. This was 2 mo earl...

Survival in liquid nitrogen of dormant vegetative buds from several cold-hardened apple cultivars was greater with buds which were dehydrated prior to cryopreservation than with nondehydrated buds. Buds collected early in the cold-acclimating period suffered injury as a result of dehydration, but the percent survival of the dehydrated buds, after s...

The survival of dormant, vegetative apple buds frozen to −30 °C or −40 °C for 5 min or 24 h prior to immersion in liquid nitrogen was investigated for 15 apple cultivars. Although survival after immersion in liquid nitrogen was optimum for the majority of cultivars when prefrozen to −30 °C for 24 h, some cultivars had low survival regardless of the...