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1.
Blueberry can readily be shaded as a bush type plant, maybe affecting its growth and photosynthesis. Growth and photosynthetic characteristics of ‘Bluecrop’ blueberry grown under various shade levels were investigated to understand acclimation under shade conditions and to determine the optimal light conditions for agricultural purpose. Shade decreased the number of shoots per shrub, but increased shoot length. However, shade did not affect the number of leaves on the main axis. With increasing shade level, leaf length, width and area increased, but leaf thickness decreased. However, there was no obvious tendency in leaf length/width ratio with increasing shade level. Shade leaves had less dense stomata than sun leaves, but stoma was bigger in shade leaves than in sun leaves. With increasing shade level, non-photochemical quenching in blueberry leaves increased and the values were higher at low photosynthetic photon flux densities (PPFDs) in shade leaves than in sun leaves, resulting in the decreases in quantum yield, electron transport rate and net CO2 assimilation rate (An). The maximum An at 31, 60, 73 and 83% shade levels was 11.8, 11.0, 8.4 and 7.5 μmol m−2 s−1, respectively. Following the slight decrease up to 100 μmol m−2 s−1 PPFD, stomatal conductance (gs) linearly increased up to 600 μmol m−2 s−1 PPFD and became saturated at all shade levels. The leaves of the shrubs grown under the 83% shade level had a significantly lower gs as compared to the leaves of the shrubs grown under the 31, 60 and 73% shade levels. Transpiration rate (E) linearly increased up to 600 μmol m−2 s−1 PPFD and was saturated at the 73 and 83% shade levels. However, E increased linearly at both 31 and 60% shade levels with increasing PPFD. The reproductive growth characteristics such as number of flowers, fruit set rate per flower bud and fruit yield also significantly decreased with increasing shade level. For agricultural purpose, therefore, shade level above approximately 60% of full sunlight must be avoided for optimal photosynthesis and growth of the ‘Bluecrop’ blueberry.  相似文献   

2.
The effects of mean daily temperature (MDT) and mean photosynthetic daily light integral (MDLI) on flowering during the finish stage of two petunia (Petunia × hybrida) cultivars were quantified. Petunia ‘Easy Wave Coral Reef’ and ‘Wave Purple’ were grown in glass-glazed greenhouses at 14–23 °C or 14–26 °C and under 4–19 mol m−2 d−1 with a 16-h photoperiod. The flower developmental rate was predicted using a model that included a linear MDT function with a base temperature multiplied by an exponential MDLI saturation function. The flower developmental rate increased and time to flower decreased as MDT increased within the temperature range studied. For example, under a MDLI of 12 mol m−2 d−1, as MDT increased from 14 to 23 °C, time to flower of ‘Easy Wave Coral Reef’ and ‘Wave Purple’ decreased from 51 to 22 d and 62 to 30 d, respectively. Flower developmental rate increased as MDLI increased until saturation at 14.1–14.4 mol m−2 d−1. Nonlinear models were generated for effects of MDT and MDLI on flower bud number and plant height at flowering. The number of flower buds at flowering increased as MDT decreased and MDLI increased. For example, at an MDT of 14 °C with 18 mol m−2 d−1, plants had 2.5–2.9 times more flower buds than those grown at 23 °C and 4 mol m−2 d−1. Models were validated with an independent data set, and the predicted time to flower, flower bud number, and plant height were within ±7 d, ±20 flowers, and ±4 cm, respectively, for 96–100%, 62–87%, and 93–100% of the observations, respectively. The models could be used during greenhouse crop production to improve scheduling and predict plant quality of these petunia cultivars.  相似文献   

3.
An in vitro plant regeneration protocol for pansy (Viola wittrockiana) cultivar ‘Caidie’ from petioles was established as following: callus induction on a half-strength MS medium supplemented with 0.45 μmol l−1 2,4-d plus 8.9 μmol l−1 BA, callus subculture on medium F (1/2MS with 4.5 μmol l−1 2,4-d, 2.7 μmol l−1 NAA and 0.44 μmol l−1 BA) and then on medium T (1/2MS with 4.5 μmol l−1 2,4-d, 2.7 μmol l−1 NAA and 2.2 μmol l−1 BA), shoot regeneration on medium D3 (MS media supplemented with 2.9 μmol l−1GA3, 23.6 μmol l−1 AgNO3, 0.02% active charcoal and 4.5 μmol l−1 TDZ), shoot multiplication on medium M (half-strength MS medium containing NAA 1.1 μmol l−1, TDZ 9.1 μmol l−1 and GA3 8.7 μmol l−1), and then shoot elongation and rooting on medium R (MS medium supplemented with 1.1 μmol l−1 NAA and 1.1 μmol l−1 BA). Subculture on appropriate medium was found to be important for successful shoot regeneration.  相似文献   

4.
Closed cycle soilless techniques can be adopted to minimize water and fertilizer losses in greenhouse cultivation. There is a general lack of information regarding the soilless cultivation of vegetables with closed cycle subirrigation techniques, specifically when using saline water. In this study, a trough bench subirrigation system (SUB), with two fertilizer concentrations (“100%”, containing 9.8 mol m−3 N-NO3, 1.6 mol m−3 P-H2PO4, 8.7 mol m−3 K+, 2.8 mol m−3 Ca+, 1.8 mol m−3 Mg+, 4 mol m−3 S-SO4, and “70%”, containing 70% of the macronutrient concentration) in the nutrient solution (NS), was compared with open cycle drip-irrigation (DRIP with “100%” NS). For all the three treatments, NS was prepared using rain water (0.05 dS m−1) and adding NaCl (1 g L−1), in order to simulate moderate saline irrigation water. The effect of the treatments on tomato (Solanum lycopersicum L.) plant growth, yield, fruit quality, water use efficiency (WUE) and fertilizer consumption was evaluated. Substrate and recirculating NS composition were also studied. Subirrigation, regardless of NS concentration, reduced plant height (by 30 cm), leaf area (by 1411 cm2), total fresh and dry weight (by 429 and 48.5 g plant−1, respectively) but not dry matter percentage of the whole plant, with respect to DRIP. Yield was reduced when plants were subirrigated with the higher concentrated NS, but no differences with open cycle DRIP were recorded when the lower NS concentration was used in SUB. Fruit quality was not affected by irrigation system or NS concentration. The higher WUE was obtained with subirrigation. NaCl accumulated similarly over the crop cycle in recirculating NS of both SUB treatments and in growing substrates of all the three treatments. Higher salt concentration was found in subirrigated substrates, in particular in the upper part of the substrate profile. Fertilizers accumulated in the subirrigated substrates when the higher NS concentration was used, but not when the NS concentration was reduced by 30%. The results of this study indicate that tomato can be grown successfully in a closed cycle subirrigation system, using saline water, by reducing the fertilizer NS concentration normally used with traditional open cycle systems.  相似文献   

5.
Difficulties to develop an easy and reproducible protocol to get healthy and well formed plants from somatic embryos of papaya (Carica papaya L.) had included low germination, callus production at the base of the embryo radicle and the occurrence of hyperhydric plantlets among others, and by consequence unsuccessful transfer to the field. With the aim of improving a propagation method, the effects of light quality, gelling agent and phloridzin concentration on the germination of somatic embryos of hermaphrodite C. papaya L. var. Maradol were studied. Somatic embryos were grown on half strength MS medium, with the addition of Chen vitamins [Chen, M.H., Wang, P.J., Maeda, E., 1987. Somatic embryogenesis and plant regeneration in Carica papaya L. tissue culture derived from root explants. Plant Cell Rep. 6, 348–351], solidified with three distinct gelling agents: Sigma® Agar–Agar, Difco® Bacto agar and Phytagel®; supplemented with phloridzin and exposed to different light qualities: blue (54 μmol m−2 s−1), red (65 μmol m−2 s−1), gro-lux (68 μmol m−2 s−1), red + blue, white (32 μmol m−2 s−1) and wide spectrum (49 μmol m−2 s−1) during a period of 4 weeks. Results show that light quality and gelling agent had important effects on germination and plant growth, while 3.0 mg L−1 phloridzin had an important role on germination as well as in root development. Somatic embryos exposed to white light, culture medium solidified with 3.0 mg L−1 phytagel and 3.0 mg L−1 phloridzin showed longer roots. Meanwhile, germination and plant length were promoted on an improved culture medium solidified with 7.5 g L−1 Difco® Bacto agar, 3.0 mg L−1 phloridzin and exposed to gro-lux lamps. Under these conditions, 70% of somatic embryos germinated and developed normal roots without hyperhydricity. The regenerated plantlets with well developed roots and shoots were successfully transferred to a greenhouse with a survival rate of 95%.  相似文献   

6.
Propagation in liquid culture, especially bioreactors, is one possible way to produce clonal propagules of Cyclamen persicum Mill. at a low cost. The current propagation method for C. persicum is from expensive hybrid seeds. This paper presents models of the potential effects of oxygen concentration, daily mean temperature, the difference between day and night temperature (DIF), and daily light integral on the development of proembryogenic masses of C. persicum Mill. in bioreactors. Each of the four growth factors was observed at three levels; oxygen concentration (50, 100 and 150% of fully oxygen saturated medium without cells), daily mean temperature (15, 20 and 25 °C), DIF (+10, 0 and −10) and daily light integral (0, 1.3 and 2.6 mol m−2 day−1). Two response variables, biomass growth and cell viability, were measured at day 0, 7, 14, 21 and 28 after start-up. The optimal values for biomass growth were 150% oxygen, 25 °C, 1.11 mol m−2 day−1 and DIF + 10. There was a stable positive linear effect from temperature. Oxygen showed a similar, but less stable effect. DIF gave maximum effect at the outer levels, and its optimum was the upper level +10. The optimal values for light were between 1.03 and 1.19 mol m−2 day−1. The optimal time for cell viability in the bioreactors was 10–11 days. Temperature and daily light integral had stable optima of 20.8 °C and 1.10 mol m−2 day−1. For oxygen the optimum was more unstable, but in most cases it was below 100%. There was no significant effect of DIF on cell viability.  相似文献   

7.
Fruit cracking after rain limits the production of a number of crops, including some Ribes species. To gain a better understanding of the factors involved in cracking, fruit growth, deposition of the cuticular membrane (CM), water uptake and fruit cracking were studied in black currant (Ribes nigrum L. cv. Zema), gooseberry (Ribes uva-crispa L. cv. Rote Triumph), and jostaberry (Ribes nidigrolaria B. cv. Jostine). Fruit surface area and fresh mass increased continuously throughout development, whereas deposition of the CM was biphasic. CM mass per fruit increased rapidly up to 42, 41, and 49 days after full bloom (DAFB) in black currant, gooseberry, and jostaberry, respectively. Thereafter, CM mass per fruit remained constant in gooseberry and jostaberry or increased at a lower rate in black currant. The cessation of or reduced rate of CM deposition resulted in a decrease in CM mass per unit area in all berries. Elastic strain of the CM at maturity averaged 23.8% and 19.5% in gooseberry and jostaberry, respectively, and only 8.2% in black currant. Microcracks in the CM were observed first in gooseberry and jostaberry 64 DAFB, whereas there were no microcracks in black currant. Water uptake into mature detached berries was linear over 2 h of incubation. Rates of uptake were highest in gooseberry followed by black currant and jostaberry. Relative uptake was similar via the cut end of the pedicel (32.1%), the apex of the fruit (34.7%) and the fruit surface (33.2%). Rates of water uptake through the fruit surface were positively related to surface area. Average fruit water potential for black currant, gooseberry, and jostaberry was −2.14 ± 0.17, −1.24 ± 0.03, and −1.89 ± 0.20 MPa, while the permeability for osmotic water uptake was 7.7 ± 0.4 × 10−8, 5.2 ± 0.1 × 10−8, and 3.3 ± 0.3 × 10−8 m s−1. Incubating whole fruit in deionized water for 72 h resulted in more cracked jostaberries (94%) than black currants (74%) or gooseberries (50%). A comparison of our findings in Ribes berries with published data for the sweet cherry drupe revealed that the berries fitted the relationships established in sweet cherry among fruit growth, cuticle deposition, strain of the cuticle, microcracking, permeability for osmotic water uptake, frequency of stomata and cracking. The Ribes berries were less susceptible to cracking than sweet cherry.  相似文献   

8.
Three greenhouse experiments were carried out to determine the growth, yield, nitrate, total N and S concentration in shoots, and water uptake of hydroponically grown Brassica rapa L. subsp. nipposinica var. chinoleifera and Brassica juncea L. In each experiment, daily photosynthetically active radiation (PAR) level was 5.0 mol m−2 (low), 6.8 mol m−2 (medium) or 9.0 mol m−2 (high). Plants were supplied with nutrient solutions having equal N concentrations of 11 mM in different forms: 100% NH4, 50% NH4 + 50% NO3, and 100% NO3. Nitrogen supplied as 100% NH4 reduced fresh and dry shoot biomass, leaf area, and leaf number in both Brassica species, especially at low and medium PAR levels. In both Brassica species, S concentrations were highest, while nitrate concentrations were lowest in leaves of plants grown at N supplied as 100% NH4. No differences in leaf nitrate concentrations were observed between 50% NH4 + 50% NO3 and 100% NO3 treatments. Low and high PAR levels increased the nitrate concentrations and decreased the N/S ratio in leaves of both crops compared to medium PAR level. Fresh shoot biomass was maximized in Brassica rapa when PAR level was above the medium value and nitrate was supplied in the nutrient solution as NO3 or as a mixture of 50% NO3 and 50% NH4. The highest fresh shoot biomass of Brassica juncea was observed in all nutrient solution treatments at high PAR level.  相似文献   

9.
The flowering responses of Brunonia australis (blue pincushion) and Calandrinia sp. to vernalization, photoperiod, temperature and plant age were investigated to provide a foundation for manipulating flowering in these potential potted plants. Plants were vernalized at 4.8 °C for 0, 3 or 6 weeks at the plant age of 1–4 or 8–14 leaves. Following vernalization, plants were grown at 25/10 or 35/20 °C (day/night) under short days (11 h, ambient daylight averaged 380 ± 44 μmol m−2 s−1) or long days (16 h) provided by an additional 5 h night break (21:00–2:00 h at <4.5 μmol m−2 s−1 from incandescent lamps), for 85 days. This is the first work to investigate flowering of these ornamental species. Both species showed enhanced flowering following vernalization and a quantitative requirement for long days. The reduction of the time until the first visible inflorescence (Brunonia) or flower (Calandrinia) buds by 8–13 days was affected by vernalization for 3 or 6 weeks, respectively. Long days were effective for reducing the time to first visible floral bud and increasing the number of inflorescence or flowers per plant for both species. For Brunonia, LDs replaced vernalization when applied to plants with 1–4 leaves. Raising temperature from 25/10 to 35/20 °C increased the number of flowers per plant of Calandrinia by 2–2.5-fold for plants with 1–4 or 8–14 leaves respectively.  相似文献   

10.
Scaevola aemula is a popular ornamental crop cultivated as a bedding plant or for hanging baskets. We characterized gas exchange properties of S. aemula ‘New Wonder’ in response to photosynthetically active radiation (PAR), carbon dioxide concentration, and leaf temperature. Net CO2 assimilation rate (A) was responsive to CO2, exhibiting a saturation when intercellular CO2 concentration (Ci) was greater than 600 μmol mol−1. Net CO2 assimilation rate and dark respiration rate (Rd) were 23.1 and 2.3 μmol m−2 s−1, respectively, at 25 °C and PAR = 1500 μmol m−2 s−1. Net CO2 assimilation rates were similar at leaf temperatures between 20 and 30 °C but significantly reduced at 15 °C. These gas exchange results were used to test the extendibility of a coupled gas exchange model previously developed for cut-roses. Utilizing the gas exchange data measured at 25 °C leaf temperature, several model parameters were independently determined for S. aemula. Model predictions were then compared with observations at different leaf temperatures. The model predicted the rates of net CO2 assimilation and transpiration of S. aemula reasonably well. Without additional calibration, the model was capable of predicting the temperature dependence of net CO2 assimilation and transpiration rates. Applying the model to predict the effects of supplemental lighting and CO2 enrichment on canopy photosynthesis and transpiration rates, we show that this model could be a useful tool for examining environmental control options for S. aemula production in the greenhouse.  相似文献   

11.
Knowledge of the factors involved, and tools to control morphology and flowering are important in intensive and cost-efficient greenhouse production. Hydrangea macrophylla is an important flowering pot plant in Norway and is produced year-around in greenhouses. Due to problems in scheduling, a study was conducted to compare floral transition and morphology of two commercially important cultivars of Hydrangea (‘Early Blue’ and ‘Schneeball’) under different flower initiating treatments in growth chambers. Plants were grown with high pressure sodium lamps (HPS) at moderate temperature (17 °C) (MT) and high (24 °C) temperature. At high temperature, the effect of (1) irradiance under long day conditions (16 h lighting with 70 or 200 μmol m−2 s−1), and (2) short day (8 h lighting) was investigated. The short day treatment had similar light integral as the low irradiance long day treatment (SD: 8 h × 140 μmol m−2 s−1 and LD: 16 h × 70 μmol m−2 s−1 = 4.0 mol m−2 d−1). The intention was to test the effect of irradiance and SD on flower transition and morphology under high temperatures. The results clearly showed that MT is the strongest signal for floral transition. MT resulted in a rapid floral transition of the terminal buds and lateral flower buds. A short forcing period was required and the plants became short and compact without any use of chemical growth retardants. At high temperatures only SD had a promotive effect on flower transition and the response was found to be stronger in ‘Schneeball’ than ‘Early Blue’. In general, all the treatments under high temperatures required a long forcing time and the plants tended to be very tall with a low number of lateral flower buds.  相似文献   

12.
Clumps of statice (Limonium latifolium) plantlets grown photomixotrophically were used as explants and cultured for 25 days on a sugar-free modified Murashige and Skoog (MS) medium in Magenta-type vessels with the number of air exchanges of the vessel (NAE) being 3.8 h−1, at a photosynthetic photon flux (PPF) of 100 μmol m−2 s−1 and a CO2 concentration of 1500 μmol mol−1 in the culture room. A factorial experiment was conducted with three levels of 6-benzylaminopurine (BA) concentration, namely 0, 0.25 and 0.5 mg L−1, and two types of supporting material, agar and Florialite (a porous material). The control treatment was a photomixotrophic culture using a sugar- and BA (0.25 mg L−1) containing agar medium in the vessel with NAE of 0.2 h−1, at a PPF of 50 μmol m−2 s−1 and a CO2 concentration of 400 μmol mol−1 in the culture room. Leaf area, chlorophyll concentration and net photosynthetic rate were greater in the sugar-free medium treatment with a BA concentration of 0.25 mg L−1 and Florialite than those in the control treatment. The number of shoots and dry weight per clump in the sugar-free medium treatment were comparable to those in the control treatment. Among the sugar-free medium treatments, the number of shoots increased with increasing BA concentration, however, the leaf area, dry weight, chlorophyll concentration and net photosynthetic rate decreased with increasing BA concentration. The use of Florialite significantly enhanced the growth and root induction as well as net photosynthetic rate, compared with the treatments that use agar. These results indicated that sugar-free medium micropropagation could be commercially applied to the multiplication of statice plantlets.  相似文献   

13.
Data on the growth-promoting effects of Azospirillum on lettuce exposed to either normal or saline conditions, is scarce. Lactuca sativa L., cv Mantecosa seeds were colonized with A. brasilense Sp245 cells during imbibition. Germination percentages were determined after 7 d treatments with 0, 30, 50 or 80 mol m−3 NaCl. In another experiment, seeds germinated in Hoagland were irrigated for 30 d with 0, 30, 50 or 80 mol m−3 NaCl supplemented media. Vegetative growth proceeded in a growth chamber with a 13–11 h day–night cycle. Buffer-imbibed seeds were considered non-inoculated controls. Plant samples were taken at 0, 14, 20, and 30 d after the onset of NaCl treatments and dissected in aerial and root portions. The weights of both tissues were measured. Azospirillum-inoculated seeds had significantly higher germination percentages than controls in all treatments. Inoculated dried seeds stored up to 30 d maintained such characteristic in most of the treatments, particularly at 80 mol m−3 NaCl. Plants grown from inoculated seeds and irrigated with saline media displayed higher total fresh and dry weights and biomass partition to the aerial portion, than non-inoculated controls. Azospirillum-inoculated lettuce seeds had better germination and vegetative growth than non-inoculated controls after being exposed to NaCl.  相似文献   

14.
Abiotic factors affect the induction of PLBs and callus in hybrid Cymbidium Twilight Moon ‘Day Light’. The initiation and proliferation of new PLBs and callus could be achieved on NAA and kinetin, supplemented at 0.1 mg l−1 each, respectively, both within 45–60 days. Bacto agar was found to be the most suitable solidifying agent for PLB induction, although a higher shoot fresh weight was obtained on Gelrite; a pH 5.3 was optimal while pH 4.5 caused 100% explant necrosis; coconut water, when supplied at 10–20% (v/v) resulted in a significant increase in the number of PLBs formed per PLB segment (23.1 versus 14.6 in controls) while a massive (almost four-fold) increase in fresh top weight occurred when PLB explants were placed in liquid culture, as a result of hyperhydricity; Fe-EDTA (1 mg l−1) and activated charcoal (1 g l−1) stimulated total fresh weight and PLB formation in the presence of PGRs; PLB formation decreased but total fresh shoot weight increased with the addition of niacin or myo-inositol, both vitamins. Dark-grown PLB-induced plants were etiolated and had longer internodes and higher fresh weight than light-grown control plants at 45 μmol m−2 s−1; at 15 μmol m−2 s−1 shoots were slightly etiolated, fragile, and PLB formation was scarce. RAPD and mtDNA analysis of all resultant PLBs, callus or plants showed them to be genetically identical, with comparable chlorophyll contents. Despite the detection of cytological variation between different plant parts, little variation resulted from abiotic factor treatment.  相似文献   

15.
The evolution, from 1 to 10 days after germination, of flavonoid content in sprouts of tartary buckwheat (Fagopyrum tataricum Gaertn.), grown in a greenhouse under low light conditions (16 μmol m−2 s−1), was investigated. Chlorogenic acid and flavonoids including C-glycosylflavones (orientin, isoorientin, vitexin, isovitexin), rutin and quercetin were separated from the sprouts by HPLC and quantified with their commercial standards. Rutin content in the edible portion of the sprouts (mean 20 and 37 mg g−1 DW in ‘Hokkai T 8’ and ‘Hokkai T 10’, respectively) was 3- to 31-fold greater than that in the roots or pericarp. The free radical scavenging activity of seed sprouts was assessed through the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. From 6 to 10 days after sowing, the free radical scavenging activity in the edible portions rose significantly from 1.52 to 2.33 μmol Trolox equiv. g−1 DW in ‘Hokkai T 8’ and from 1.46 to 2.09 μmol Trolox equiv. g−1 DW in ‘Hokkai T 10’, but differences between ‘Hokkai T 8’ and ‘Hokkai T 10’ were not significant. As the results, the sprouts of tartary buckwheat, particularly those of ‘Hokkai T 10’ are strongly recommended as new high rutin food.  相似文献   

16.
In the daytime, a CO2 depletion of 10–15% and air circulation of less than 0.5 m s−1 often occur in a naturally ventilated greenhouse during a sunny day with high wind speed (3–5 m s−1). We, therefore, investigated the effects of moderate increase of the CO2 concentration above the atmospheric level (500–600 μmol mol−1) and air circulation up to 1.0 m s−1 in a growth chamber on the net photosynthetic and transpiration rates of tomato seedlings as the first step. The average net photosynthetic rates were 2.1, 1.8, and 1.6 times higher in the growth chambers with increased CO2 concentration (500–600 μmol mol−1) and air circulation (1.0 m s−1), increased CO2 concentration, and increased air circulation, respectively, compared with those in the control (no increase in CO2 concentration (200–300 μmol mol−1) or air circulation (0.3 m s−1). The transpiration rate increased with increased air circulation, while it decreased with increased CO2 concentration regardless of air circulation. From the results, we consider that increasing the CO2 concentration and/or air circulation in ventilated greenhouses up to the outside concentration (350–450 μmol mol−1) and 1.0 m s−1, respectively, can significantly increase the net photosynthetic rate of greenhouse plants.  相似文献   

17.
Seven wild and ten cultivated blackberries (Arapaho, Bartin, Black Satin, Bursa 1, Bursa 2, Cherokee, Chester, Jumbo, Navaho, and Ness), and six lowbush (Vaccinium arctostaphylos) and four highbush (Vaccinium corymbosum) blueberries fruits (Ivanhoe, Jersey, Northland, and Rekord) were analyzed for total anthocyanins, total phenolics, and antioxidant activity as ferric reducing antioxidant power (FRAP) in this study. The respective ranges of total anthocyanin and total phenolic contents of the tested samples were: blackberries, 0.95–1.97 and 1.73–3.79 mg g−1 and blueberries, 0.18–2.94 and 0.77–5.42 mg g−1. FRAP values varied from 35.05 to 70.41 μmol g−1 for blackberries, 7.41 to 57.92 μmol g−1 for blueberries. Wild blackberries had the highest FRAP values while wild blueberries had the highest total phenolic and total anthocyanin contents. A linear relationship was observed between FRAP values and total phenolics for blueberries (r = 0.981). The anthocyanin pigments in samples were isolated and characterized by high-performance liquid chromatography (HPLC) with UV–visible detection. Cyn-3-glu was the predominant anthocyanin in all blackberry fruits.  相似文献   

18.
To develop efficient seedling production methods for Laccosperma secundiflorum and Eremospatha macrocarpa, a study was conducted to examine regeneration using offsets combined with several physical and chemical treatments of seeds. Offsets categorized into small, medium and large diameters, were planted in three conditions: shaded and open nursery, and greenhouse. We tested sucker from E. macrocarpa, and sucker and rhizome from L. secundiflorum. For both species, high viability percentage (ranging from 55% to 100%) were observed for small and medium suckers planted in shaded nursery and greenhouse, against less than 49% for sucker planted in open nursery. The mean seedling emergence times were estimated to 84, 77 and 75 days after planting (DAP) for small, medium and large sucker of L. secundiflorum, respectively under open nursery condition, and 76, 75, 95 DAP for small, medium and large suckers of the same species, respectively in shaded condition. Greenhouse has a significant positive effect on E. macrocarpa seedlings emergence time. For this species, the mean seedling emergence times were estimated to 43 DAP for small sucker and 76, 93 DAP for medium and large suckers. No seedling was obtained from rhizome planted in all the growing conditions tested. Concerning seed dormancy breaking, germination percentages and rates were determined for 13 treatments. The best treatments were pre-soaking unscarified seeds for 4 days in 1.01 g l−1 and 0.10 g l−1 KNO3, with 79% and 68% of germination, respectively and in 3.46 × 10−3 g l−1 GA3 for 68% of germination. These methods are suggested to improve germination of L. secundiflorum seeds. Successful and recommended methods for E. macrocarpa are pre-soaking scarified seeds in 3.46 × 10−3 g l−1 and 3.46 × 10−4 g l−1 GA3, 96% and 94% of germination, respectively. Dormancy, probably a combination of mechanical and chemical dormancy, is present in the two species.  相似文献   

19.
The effects of night interruption (NI) were examined on the vegetative growth and flowering of Cymbidium ‘Red Fire’ and ‘Yokihi’. Plants were grown under 9/15 h ambient light/dark (control), 9 h ambient light plus night interruption (22:00–02:00 h) with low light intensity at 3–7 μmol m−2 s−1 (LNI) and 9 h ambient light plus NI with high light intensity at 120 μmol m−2 s−1 (HNI) conditions. The number of leaves, leaf length, number of pseudobulbs and pseudobulb diameter increased in both LNI and HNI compared to controls for both cultivars. While none of the control plants flowered within 2 years, 100% of the ‘Yokihi’ and 80% of the ‘Red Fire’ plants grown under HNI condition flowered. In the LNI group, 60% of the plants flowered in both cultivars. Plants in the HNI group showed a decreased time to visible inflorescence and flowering than those in the LNI group. The number of inflorescences and florets were greater in the plants grown under HNI than those in the LNI group. The tallest plants at flowering were in the HNI group in both cultivars. NI with low light intensity can be used effectively to promote flower induction with increased growth rate during the juvenile stage in Cymbidium. To obtain high quality plants, however, NI with high light intensity strategies should be considered.  相似文献   

20.
The effects of plant density on broccoli (Brassica oleracea L. var. italica Plenck) commercial characteristics are well determined. However, it is not completely clear how the broccoli plant respond to changes in plant shading as a result of different plant densities. The objective of this experiment was to determine the effect of plant density on intercepted photosynthetically active radiation (PAR), plant architecture, and plant growth and production. “Legacy” broccoli plants were grown in pots in a greenhouse in the seasons of 2002 and 2003 at 2, 4, 6 or 8 plants m−2 (temperatures: between 10.0 and 16.1 °C, average incident PAR: 12 mol m−2 day−1). Plant density affected the intercepted and accumulated PAR. There were not effects on the length of the vegetative and reproductive periods, the total and final number of leaves, and the spear diameter and fresh weight. The magnitude and evolution of leaf area (LA) was independent of plant density up to 70 days after transplant (dat). Since then on, LA increased linearly with plant density. The highest intercepted PAR was 70–72% with 6–8 plants m−2. With the increase in plant density: the erectness of the upper leaves and stem length increased, the extinction coefficient decreased and commercial spear (inflorescence plus a portion of stem 10 cm long) weight decreased (but it was due to the stem portion of the spear and not to the edible portion). On an area basis, the decrease in commercial spear weight with plant density was more than compensated by the higher number of plants. The radiation use efficiency (RUE) increased proportionally with the leaf area index (LAI) up to a LAI of about 3, and then stabilized. The only effect of plant density on dry weight partitioning was to decrease the dry weight allocated to the stem portion of the spear. As plant density increased, and consequently the degree of shading increased, the net assimilation rate (NAR) decreased and the leaf area ratio (LAR) increased. This compensatory change between NAR and LAR, kept the relative growth rate (RGR) for individual plants almost constant.  相似文献   

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