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An efficient procedure for the conservation of mature American elm (Ulmus americana L.) trees that have survived the epidemics of Dutch elm disease and are potential sources of disease resistance is reported. The model utilizes in vitro proliferation of fresh and dormant buds from mature trees for cloning nearly 100 year old American elm trees. The key factors that influenced sustained growth and multiplication included optimization of culture process and auxin metabolism in the source tissue. Blocking the action of endogenous auxins through the addition of antiauxin in the proliferation medium was crucial for high multiplication rate and optimum shoot development. Addition of antiauxin also mitigated the decline in productivity observed with multiple subcultures, which will enable long-term conservation of selected germplasm. The most effective medium for long-term proliferation contained 5.0 umol/L p-chlorophenoxyisobutyric acid with 2.2 umol/L benzylaminopurine and 0.29 umol/L gibberellic acid. Medium with 2.5 umol/L indole-3-butyric acid was the best for rooting microshoots (89%). Rooted plantlets were readily acclimatized to the greenhouse environment with a 90% survival rate. The strategy developed for American elm will aid in increasing multiplication of resistant clones, facilitate long-term conservation of elite genotypes, and also provide an approach to improve conservation of other endangered tree species. Resume: Une methode efficace pour conserver les ormes d'Amerique (Ulmus americana L.) matures qui ont survecu aux epidemies de la maladie hollandaise de l'orme et qui constituent des sources potentielles de resistance a la maladie est rapportee. Le modele utilise la propagation in vitro de bourgeons frais et dormants provenant d'arbres matures pour cloner des ormes d'Amerique qui ont presque 100 ans. Les facteurs cles qui assurent une multiplication et une croissance soutenues incluent l'optimisation du processus de culture et du metabolisme des auxines dans les tissus souches. Il etait essentiel de bloquer l'action des auxines endogenes par l'addition d'antiauxine dans le milieu de propagation pour obtenir un taux eleve de multiplication et un developpement optimal des pousses. L'addition d'antiauxine a egalement attenue le declin de productivite observe a cause des multiples souscultures, ce qui rendra possible la conservation a long terme du germoplasme selectionne. Le milieu le plus efficace pour la propagation a long terme contenait 5,0 umol/L d'acide p-chlorophenoxyisobutyrique avec 2,2 umol/L de benzylaminopurine et 0,29 umol/L d'acide gibberellique. Le milieu contenant 2,5 umol/L d'acide indole 3-butyrique etait le meilleur milieu pour enraciner les micropousses (89 %). Les plantules enracinees s'acclimataient facilement en serre avec un taux de survie de 90 %. La strategie qui a ete developpee pour l'orme d'Amerique pourra contribuer a accro?tre la multiplication des clones resistants, a faciliter la conservation a long terme de genotypes elites et egalement a fournir une approche pour ameliorer la conservation d'autres especes d'arbre menacees. [Traduit par la Redaction], Introduction The American elm (Ulmus americana L.) is a North American species belonging to the family Ulmaceae and is highly prized as an urban landscaping tree admired for its arching [...]

The study objective was to determine the effects of field application of hexanal on pre-harvest market attributes of orange (Citrus sinensis L.) fruits. The first factor was hexanal concentration (0.01, 0.02, 0.04% and controls – untreated fruits), the second factor consisted of time of hexanal application prior to fruit harvest (7, 21, 42 and 60 days to harvest) and the third factor was season (1st and 2nd season). Tested orange varieties were Early Valencia ('Msasa'), Jaffa and Late Valencia varieties. A fruit tree for each orange variety constituted a treatment for hexanal application and time of its application prior to fruit harvest. The results show that hexanal application at 0.01, 0.02 and 0.04% equally improved fruit marketable yields by increasing fruit firmness and number of marketable fruit of Early Valencia, Jaffa and Late Valencia varieties. Number of marketable fruit increased by 34.89%, 34.04% and 42.48% over the controls for Early Valencia, Jaffa and Late Valencia, respectively. Similarly, fruit firmness increased by 11.38, 11.03 and 11.92 N/mm2 over the control for Early Valencia, Jaffa and Late Valencia, respectively. It is recommended that farmers should treat Early Valencia, Jaffa and Late Valencia with hexanal at 0.01% in order to increase marketable yield and fruit quality. [ABSTRACT FROM AUTHOR]

Mango (Mangifera indica L.) production is constrained by several pre-harvest factors. This study determined the effects of enhanced freshness formulation (EFF) on yield losses in "Apple," "Palmer" and "Keitt" varieties. Factorial experiments tested the effects of EFF concentrations, seasons, varieties, and times of EFF application on percentage of dropped fruit, non-marketable yield and incidences of pest defects. Percentage of dropped mango was significantly (p < 0.001) affected by EFF concentration, time of application and season, EFF × season, EFF × variety, time × season, time × variety, and time × variety × season interactions. Non-marketable mango fruits were significantly (p < 0.001) affected by EFF concentration, variety, EFF concentration × season, variety × season and variety × time of application. Incidences of pest defects were significantly (p < 0.001) affected by EFF concentration and EFF concentration × season and variety × season. EFF concentration of 0.01% is recommended to reduce yield losses. [ABSTRACT FROM AUTHOR]

Experiments were conducted to assess the effects of hexanal, calcium chloride, and smoke on the post-harvest quality of oranges under ambient (room) temperature (28±2°C) and reduced temperature storage (18±2°C) conditions on two varieties of sweet orange (Citrus x sinensis (L.) Osbeck) cvs 'Msasa' and 'Jaffa'. Fruit were dipped in enhanced freshness formulation (EFF) containing hexanal as the key ingredient at 0.01%, 0.02%, and 0.04% (volume/volume), or calcium chloride solution at 1%, 2%, and 4% (weight/volume) for five minutes each, or subjected to a smoking regime, simulating a popular traditional practice, by burning 0.5 kg, 1.0 kg, and 1.5 kg of dried banana leaves, or left untreated (control). Various parameters including physiological weight loss, fruit firmness, total soluble solids (TSS), titratable acidity (TA), and the TSS/TA ratio were assessed to determine effects on post-harvest quality of fruit. Results indicate that hexanal and calcium chloride treatments significantly (p < 0.001) reduced physiological weight loss, maintained fruit firmness and significantly higher TSS in both varieties compared to smoke treatment and untreated controls. Reduced temperature storage also significantly (p < 0.001) lowered physiological weight loss of hexanal- and calcium chloride-treated oranges. Based on the results of this study, post-harvest dip treatments with hexanal solution at 0.02% or calcium chloride solution at 2% coupled with reduced temperature storage at 18°C are recommended to maintain the quality of fresh oranges in Tanzania. On the contrary, the application of smoke is highly discouraged as it reduces the quality of oranges. [ABSTRACT FROM AUTHOR]

A laboratory study was undertaken to determine the effects of a nano-emulsion carrying hexanal, an enhanced freshness formulation (EFF), as a post-harvest dip technology to minimize the post-harvest losses and to extend the shelf life of bananas. The banana fruits were harvested at three maturities (95%, 85%, and 75%), dipped or not dipped in the EFF, and studied under both ambient and reduced temperature storage conditions. During the experiments, the fruit's physical, physiological, and biochemical parameters were periodically evaluated. The treated fruit had lower physiological loss of weight and higher firmness throughout the study period, regardless of maturity level at the start. Treated fruit had higher total soluble solids and total sugars, and less acidity indicating improved fruit quality during storage, in addition to an extended shelf life. High resolution imaging using scanning electron microscopy showed that EFF-treated fruit exhibited well maintained structural lenticels on the fruit skin and deposition of starch granules in the fruit pulp, regardless of maturity level at the start. Overall, the results clearly indicated that the EFF-treated banana fruit were delayed in the ripening process and had an extended shelf life of up to six days in ambient conditions and nine days in cold storage conditions. Post-harvest dipping using hexanal formulation is a potential technology that could be adopted in pack houses for domestic and export markets. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Plant Science is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Plant Science is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Plant Science is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The article discusses a study which tested 11 cultivars of potato with a wide range of skin and flesh colours and grown over two years in 2008 and 2009 in Elora, Ontario for the total phenolic content (TPC), total anthocyanin-content (TAC) and total antioxidant activity (TAA). Results showed significant variations among cultivars for both years. The results suggested that purple/red potato cultivars have a greater potential as functional foods for enhanced human health benefits.

The article discusses the results of a study on the storage and harvest stability of potatoes. The authors explain that reducing sugar content of potatoes determined their processing quality for French fries. The study reveals that the stability and color of potatoes in French fries changed after planting harvest dates. The significance of genotypes stability for French fry color is also discussed.

Primocane-fruiting (PF) red raspberries (Rubus idaeus L. cvs. Summit and Heritage) at two locations in Southern Ontario were maintained in a hedgerow or trained to a V-trellis to determine the effect of trellising on productivity. Trellising increased yield per cane in 'Heritage' at Cambridge by 56% with a concomitant increase in fruit number per cane, but did not significantly affect yield of either 'Heritage' or 'Summit'at Campbellville. Plots at Campbellville had significantly greater cane densities than plots at Cambridge, and so light penetration into the walls of the V-trellis at Campbellville was likely diminished due to crowding and competition between canes. Response of PF raspberries to V-trellising may be dependent on cane density of the planting. [ABSTRACT FROM PUBLISHER]

Post-harvest technologies play a key role in enhancing shelf life and maintaining quality characteristics of tender fruits such as nectarines ( Prunus persica [L.] Batsch var. nectarina). This research investigated the effects of an ‘Enhanced Freshness Formulation’ (EFF) with hexanal as the key ingredient in enhancing shelf life of field grown nectarines. Pre-harvest sprays of EFF on ‘Fantasia’ nectarines, conducted at two commercial orchards in the Niagara region, ON, showed improvement in shelf life. Application of hexanal formulation delayed the incidence of chilling injury symptoms (internal browning and mealiness/woolliness) by one week. As well, treated fruits maintained significantly higher firmness until 38d post-harvest. There were no differences in total soluble solids, titratable acidity and color values between treated and control fruits. qRT-PCR was conducted to evaluate the expression levels of 22 genes potentially involved in ripening, to understand the regulatory effects of the hexanal formulation. EFF application induced a highly significant reduction in transcript levels of three Phospholipase D genes, five N-glycoprotein group genes, and other genes involved in ripening and softening processes. These findings indicate that, a delay in the ripening process caused by hexanal formulation, may be associated with the modulation of the expression of key ripening related genes, enhancing shelf life and quality of nectarines. [ABSTRACT FROM AUTHOR]

Primulina dryas ( P. dryas ), a popular ornamental plant species has recently gained interest among hobbyists and collectors due to its attractive foliage and flowers. An efficient protocol for in vitro regeneration of P. dryas from leaf and petiole explants was developed using thidiazuron (TDZ) as the sole inductive stimulus. The objective of this study was to evaluate the potential of P. dryas for mass propagation in vitro. Orientation of the explants on the culture medium also affected regeneration with significant enhancement in the number of shoots and somatic embryos when the abaxial surface of the leaf was in contact with the culture medium. Explants also showed a capacity to regenerate on a medium devoid of growth regulators indicating active endogenous hormone metabolism sufficient to stimulate de novo differentiation. The inhibitors of auxin biosynthesis and transport, p -chlorophenoxyisobutyric acid (PCIB) and 2,3,5-triiodobenzoic acid (TIBA) significantly reduced regeneration in an optimal growth environment suggesting the involvement of endogenous auxin in regeneration of P. dryas . Growth and development of regenerants was further improved in temporary immersion bioreactors and the resulting plants were successfully transplanted in the greenhouse. High efficiency and reproducibility of Primulina regeneration system reported here may facilitate large scale production of this ornamental species. [ABSTRACT FROM AUTHOR]

Abstract: Three advanced raspberry (Rubus idaeus L.) lines from the University of Guelph breeding program (‘88-18’, ‘88-117’, ‘88-134’) and one advanced line from the Quebec fruit breeding program (‘SJR942-7’) were tested for their winter hardiness, fruit quality, horticultural characteristics and antioxidant activity compared to four commercially grown cultivars (‘Festival’, ‘Boyne’, ‘Nova’ and ‘Killarney’) recommended for Quebec. Lines ‘88-18’ from Guelph and ‘SJR942-7’ from Quebec had higher antioxidant activity, larger fruit size, better fruit quality and longer shelf life than all other lines and cultivars tested. The ellagic acid content of ‘SJR942-7’ was approximately two times higher than that of the commercial cultivars grown in Quebec. [Copyright &y& Elsevier]

In order to gain an understanding of the capacity of severely shaded leaves to be productive in dense canopies, the effects of increased shading on morphology, dry-matter partitioning, and whole-plant net carbon exchange rate (NCER) were investigated on greenhouse-grown Vitis vinifera L. `Chardonnay' grapevines. Vines were subjected to whole-plant shading levels of 0%, 54%, 90%, and 99% of direct sun 3 weeks after potting. Data were collected 8 to 10 weeks after potting. Nonlinear regression was used to investigate the relationship of leaf morphological traits and organ dry weights to increased shading. Leaf size was maintained with increased shading to approximately the 90% shading level, while leaf fresh weight, volume, density, and thickness were immediately reduced with increased shading. Root dry weight was most affected by increased shading, and root to shoot ratio was reduced. When nonlinear regressions were produced for light response curves, light compensation point was reduced by approximately 49% by moderate shading, and 61%% by severe shading. Shaded leaves approached the asymptote of the light response curve more quickly, and had reduced dark respiration rates, indicating that the morphological compensation responses by the vine allow shaded leaves to use available light more efficiently. However, the long-term ramifications of reduced root growth in the current year on vines with shaded leaves may be significant. [ABSTRACT FROM AUTHOR]

• Hexanal formulation increased the fruit retention in Honeycrisp apples. • Pre-harvest spraying of Honeycrisp apples reduced the incidence and progression of bitter pit. • Hexanal reduced the phospholipase D enzyme activity and ethylene evolution. • Hexanal application helps retain the integrity of the cell wall. 'Honeycrisp' is a popular apple variety among consumers due to its desirable flavour and characteristic texture. However, this variety is highly prone to pre-harvest fruit drop, bitter pit and decline in quality during long-term storage. This research investigated the effects of hexanal as a formulation (named by us as Enhanced Freshness Formulation -EFF) on fruit retention and post-harvest shelf-life in 'Honeycrisp' apples. Hexanal is a known inhibitor of phospholipase D (PLD). Our results indicated that hexanal application reduced PLD enzyme activity from 30 days post-harvest to the end of the storage period compared to the other treatments. Ethylene production was reduced with hexanal treatment from 0 to 90 days post-harvest. An increase in total soluble solids and a decrease in physiological loss in weight was observed with hexanal application. A significantly lower occurrence of progression and severity of bitter pit was observed, while incidence of bitter was reduced by 70 %. Further electron micrographs revealed that hexanal treated apples had higher structural integrity overall. Our results reveal that application of hexanal can reduce bitter pit incidence in Honeycrisp apples, while increasing the post-harvets storage. [ABSTRACT FROM AUTHOR]

The article presents information on St-Jean D'Orleans', a new June-bearing strawberry cultivar that was introduced because of its fruit that has an excellent shelf life and resistance to leaf diseases. Data on the origin of St-Jean d-Orleans' is presented. The description and performance of the plant is discussed, as well as area of adaptation and uses.

'Clé des Champs' is a new June-bearing strawberry cultivar (Fragaria xananassa Duch.) bred for Eastern Central Canada and climates similar to Quebec conditions. 'Clé des Champs' was released for pick-your-own and shipping because it has very attractive light red, glossy (Fig. 1), and firm fruit, which have an excellent shelf life compared with 'Kent'. [ABSTRACT FROM AUTHOR]

The article features the Saint-Laurent d'Orléans' strawberry from a new June bearing strawberry cultivar released by Agriculture and Agri-Food Canada. It has a large, very firm, light red shiny fruit. The strawberry has an excellent shelf life and resistance to leaf diseases. It was named after the village of Saint-Laurent d'Orléans in Quebec.

Raspberry (Rubus spp.) is an economically important crop with a restricted growing season and very limited fruit shelf-life due to its extreme tenderness. In order to prolong its shelf life, an aqueous composition containing hexanal as the key active ingredient (HC) was applied as a preharvest spray during fruit development. The effects of HC were assessed using physiological, biochemical and anatomical parameters on the treated fruits and compared with the effects of mock inoculation which lacked hexanal. Sugars and acidity did not show a significant change in response to HC treatment, while the pulling force (the tension required to detach the berry from the receptacle) significantly improved in the HC-treated fruits, compared to control. Scanning electron microscope (SEM) analysis revealed a high correlation between the presence of rigid epidermal hairs and a stronger degree of attachment between berries and their receptacle in the HC treated fruits. Further, electron micrographs also showed abnormal crystalline depositions on the epidermal drupelets of the treated berries. Energy Dispersive X-ray Spectroscopy (EDS) analysis showed those crystals to be largely composed of calcium. HC treatment also resulted in the reduction of transcript level of three phospholipase D genes, as well as altered expression pattern of five members of the annexin gene family, and four calmodulin-binding transcription activators. Quantification of PLD activity showed that hexanal inhibited PLD activity in treated berries. The potential crosstalk between hexanal, phospholipase D activity and calcium and this crosstalk's role in delaying fruit softening and in prolonging storage life of fruits shelf life is discussed., Competing Interests: The authors declare no conflict of interest.

Greenhouse and field experiments with American ginseng (Panax quinquefolius L.) stratified seed sown at depths of 10 to 100 mm were carried out to determine effects of seeding depth on seedling emergence, growth and development and to calculate optimum seeding depth. The time to 50% seedling emergence (E50) in the field increased linearly from 17 d at 20 mm seeding depth to 42.5 d at 80 mm. Seedling emergence and root weight (economic yield) at the end of the first year each increased quadratically with the increase of seeding depth. Maximum emergence and root yields were produced at sowing depths of 26.9 and 30.6 mm respectively. In a greenhouse pot experiment, increasing seeding depth from 10 to 100 mm increased partitioning of dry matter to leaves from 23.6% to 26.1%, to stems from 6.9% to 14.2%, and decreased dry matter to roots from 69.5% to 59.7%. Optimum seeding depth was 31.1 mm for a corresponding maximum root weight of 119.9 mg. A predictor equation [X (seeding depth, mm)=Y (seed weight, mg)/9.1+20.96] for seeding depth for ginseng, based on data for ten vegetable crops, their seed weights and suggested seeding depths, predicted a seeding depth of 28.3 mm for ginseng similar to that reported above for most pot and field experiments.

Micropropagation is an important tool for rapid multiplication and the creation of genetic variability in African violets (Saintpaulia ionantha Wendl.). Successful in vitro propagation depends on the specific requirements and precise manipulation of various factors such as the type of explants used, physiological state of the mother plant, plant growth regulators in the culture medium, and growth conditions. Development of cost-effective protocols with a high rate of multiplication is a crucial requirement for commercial application of micropropagation. The current chapter describes an optimized protocol for micropropagation of African violets using leaf explants obtained from in vitro grown plants. In this process, plant regeneration occurs via both somatic embryogenesis and shoot organogenesis simultaneously in the explants induced with the growth regulator thidiazuron (TDZ; N-phenyl-N'-1,2,3-thidiazol-5-ylurea). The protocol is simple, rapid, and efficient for large-scale propagation of African violet and the dual routes of regeneration allow for multiple applications of the technology from simple clonal propagation to induction or selection of variants to the production of synthetic seeds.

The purpose of this study was to investigate whether the effects of cooling and reheating on the glycaemic index (GI) of novel potato clones (selections) differed depending on selection and whether cooling altered starch absorption in vivo. We conducted 3 experiments using 4 novel potato clones in healthy subjects. Experiment 1: the GI of 4 selections each prepared in 3 ways (freshly boiled, cooled, or cooled and reheated) was measured in 2 groups of 10 subjects (each group tested 2 selections). Experiment 2 (n=10): two selections from Experiment 1 were re-tested one year later, by a different subject group. Experiment 3 (n=10): two selections from Experiment 1 were tested by subjects from Experiment 2 to assess the rate and extent of starch absorption using the second-meal effect and the breath hydrogen method, respectively. Experiment 1 demonstrated a selection×treatment interaction for GI (p=0.024); cooling reduced the GI of two selections by 40-50% (p<0.05) but reduced GI of the other 2 by only 8-10% (ns). Experiment 2 confirmed the selection×treatment interaction (p=0.018) seen in Experiment 1. Experiment 3: cooling reduced the GI by an average of 37% (p<0.05) but only increased starch malabsorption in vivo from 3% to 5% (p=0.021); there was no significant second-meal effect. It is concluded that the effect of cooling on the GI of potatoes may vary from 0-50% depending on selection. However, the mechanism for the effect is not clear: the 2% increase in starch malabsorption seen upon cooling potatoes was not nearly enough to account for the 37% reduction in GI., (This journal is © The Royal Society of Chemistry 2011)