共查询到20条相似文献,搜索用时 31 毫秒
1.
SummaryAvocado fruits were washed with 200 µg l –1 active chlorine, partially ripened to a firmness of about 12.5 ± 0.6 kg cm –2, and sliced. Fruit slices were dipped in 1.0 mg l –1 citric acid and 200 µg l –1 ascorbic acid maintained at 4°–6°C for 2 min, dried with tissue paper and packaged in 0.05 mm or 0.075 mm-thick low density polyethylene (LDPE) at a 1:1 surface area to product weight ratio (cm 2 g –1). Sodium chloride (1 g) sealed in 0.075 mm-thick poly-coated paper pouches was included in the packages for moisture absorption. In-package O 2 and CO 2 concentrations, as well as the ethanol and acetaldehyde concentrations, firmness and lightness (L * value) of the tissue slices were measured during storage for 10 d. The sensory attributes of the modified atmosphere (MA)-packaged slices were compared with fresh fruit slices. In-package O 2 concentrations fell from 14.1% to 6.3% and CO 2 concentrations rose from 4.7% to 4.9%. Ethanol concentrations increased from 9.0 to 32.1 µg g –1 and acetaldehyde from 1.1 to 3.8 µg g –1 during storage from day-1 to day-10 in the 0.05 mm-thick LDPE with sodium chloride moisture absorbers. In-package concentrations of O 2 fell from 10.8% to 3.8% and CO 2 rose from 3.8% to 8.1%, while ethanol concentrations increased from 10.0 to 40.4 µg g –1 and acetaldehyde from 1.3 to 4.7 µg g –1 during storage from day-1 to day-10 in the 0.075 mm-thick LDPE with sodium chloride moisture absorbers. The L * value and sensory attributes of avocado slices packaged in 0.05 mm-thick LDPE, with moisture absorbers, were not significantly different from fresh slices, indicating the effectiveness of these MA conditions. Regardless of packaging conditions, avocado slices reached the firmness values of 5.8–6.3 kg cm –2 required for the ‘table-ripe’ stage on day-10 in storage. Therefore, packaging of ‘Booth 7’ avocado slices in 0.05 mm-thick LDPE with sodium chloride as a moisture absorber resulted in a storage-life of 10 d at 8°C and 90 ± 2% RH. 相似文献
2.
The effect of atmospheres containing high CO 2 and low O 2 on the firmness of kiwifruit ( Actinidia chinensis Planch.) during cool storage at 0°C has been studied. Atmospheres containing above 4% CO 2 with 15–20%O 2 caused a retardation in the softening of kiwifruit. This effect increased as the CO 2 content of the atmosphere increased from 4 to 10%, but additional CO 2 above 10% had no further effect on fruit firmness. Low O 2 (2–3%) with 3–5% CO 2 further delayed the rate of kiwifruit softening and increased storage life up to 3–4 months beyond normal air-storage life. Although controlled-atmosphere storage increases storage life of kiwifruit, the magnitude of the effect was found to vary from year to year. Contamination of the storage atmosphere by as little as 0.1 μl ?1 ethylene severely reduced the effectiveness of controlled-atmosphere storage in maintaining kiwifruit firmness, even at 0°C. 相似文献
3.
Storage of ‘McIntosh’ Apples ( Malus domestica Borkh.) in a controlled atmosphere (CA) with very low O 2 (1.5% CO 2 + 1.0% O 2, 2.8°C) retained greater fruit firmness and titratable acids during storage and during subsequent air storage than apples stored in conventional CA (5.0% CO 2 + 3.0% O 2, 2.8°C). The rate of firmness loss during subsequent 0°C air storage decreased with length of storage in CA. Storage of apples in very low O 2 for 40 or 80 days decreased the rate of firmness loss in subsequent 0°C air storage as compared to the rate of firmness loss in conventional CA fruit, but the rate of firmness loss in 0°C air storage subsequent to 160 or 320 days of conventional CA was significantly less than the loss in similar fruit stored in very low O 2 atmospheres.A modified atmosphere with 1.0% O 2 decreased the rate of C 2H 4 accumulation in storage, and fruit production of both C 2H 4 and CO 2 after storage opening in comparison with similar fruit in conventional CA. The accumulation of C 2H 4 in storage chambers was increased with increasing O 2 levels, but the rate of increase depended upon the CO 2 level. C 2H 4 storage accumulation was stimulated by the presence of CO 2 at 0.5% O 2, but was suppressed by CO 2 when 3.0% O 2 was maintained.Retention of fruit firmness and titratable acids in apples stored in 1.5% CO 2 + 1.0% O 2 were insensitive to very low (0.231 ml l ?1) or very high (2440 ml l ?1) C 2H 4 levels in storage. Scrubbing C 2H 4 (0.304 ml l ?1) from chambers held at 5.0% CO 2 + 3.0% O 2 resulted in significantly firmer fruit after storage, but this effect was not significant after shelf life of 7 days at 20°C. 相似文献
4.
We investigated the embryo induction of papaya by anther culture, and identified the sex of plantlets derived from embryos using a sex-diagnostic PCR. Anthers, containing approximately 80% uninucleate pollen, were collected from 10 to 14 mm long male flower buds. They were pre-treated on agar (0.8%) or in liquid medium for 1–5 days at 25 or 35 °C, then transferred to agar medium with 0.1 mg l −1 BA and 0.1 mg l −1 NAA. Agar and liquid media used for the pre-treatment contained water only or MS nutrients with or without sucrose (2.0%). On the agar medium, no embryos were induced at any pre-treatment temperature. In the liquid medium at 25 °C, embryos were induced at about 1.0% (rate of anthers forming embryos) in MS medium with sucrose for 3 or 5 days. At 35 °C, embryo induction rate tended to increase up to about 4.0% when anthers were treated in water for 1 day or MS medium with sucrose for 3 or 5 days. The sex of plantlets established through anther culture was analyzed using a sex-diagnostic PCR. All plantlets were determined as female. From these results, we suggest that all plantlets established through anther culture were of microspore origin, and that the anther culture technique is useful for the breeding of female papaya. 相似文献
5.
SummaryExperiments were conducted to observe the effect of different concentrations of 1-methylcyclopropene (1-MCP) on the post-harvest life and quality of ‘Allison’ kiwifruit ( Actinidia deliciosa). Fruit were treated with 1-MCP at 0.5 µl l –1, 1.0 µl l –1, or 2.0 µl l –1, un-treated fruit served as controls. Each 1-MCP treatment was applied for 24 h at 20°C. After treatment, fruit were transferred to ambient temperature storage (22º ± 4ºC; 65 – 70% relative humidity) for 18 d, during which time observations on various physical, physiological, and biochemical parameters were recorded at 3 d intervals. Our results indicated that 2.0 µl l –1 1-MCP was the most effective treatment to delay softening and ripening in ‘Allison’ kiwifruit, as such fruit showed the lowest mean weight loss (9.8 ± 0.2%), the highest mean fruit firmness value (32.7 ± 0.2 N), and began to ripen only after 12 d in storage, whereas untreated fruit started ripening on day-6 of storage. The activities of fruit softening enzymes such as polygalacturonase (PG; 58.5 ± 0.3 µg galacturonic acid g –1 FW h –1), and lipoxygenase (LOX; 3.96 ± 1.3 µmoles linoleic acid oxidised min –1 g –1 FW h –1) were lower, and total phenolics (TP) contents (24.3 ± 0.3 mg 100 g –1) and anti-oxidant (AOX) activities (12.5 ± 0.03 µmol Trolox g –1 FW h –1) were higher in 1-MCP-treated fruit than in untreated fruit (PG, 98.3 ± 0.5 µg galacturonic acid g –1 FW h –1; LOX, 4.39 ± 1.0 µmoles min –1 g –1 FW h –1; TP, 5.3 ± 0.6 mg 100 g –1; AOX, 4.7 ± 0.02 µmol Trolox g –1 FW h –1, respectively). In addition, 1-MCP-treated fruit exhibited lower rates of respiration (48.3 ± 0.4 ml CO 2 kg –1 h –1) and ethylene production (30.2 ± 0.02 µl kg –1 FW h –1) than untreated fruit (58.9 ± 0.6 ml CO 2 kg –1 h –1; 38.7 ± 0.04 µl kg –1 FW h –1, respectively). Similarly, 1-MCP-treated fruit had higher titratable acidity (TA; 1.33 ± 0.3%) and ascorbic acid (AA) contents (115.9 ± 2.6 mg 100 g –1 pulp) and lower soluble solids contents (SSC; 8.33º ± 0.2º Brix) than untreated kiwifruit (TA, 1.0 ± 0.2 %; AA, 105.3 ± 2.2 mg 100 g –1 pulp; SSC, 13.7º ± 0.3º Brix, respectively). Thus, 2.0 µl l –1 1-MCP can be used for the post-harvest treatment of ‘Allison’ kiwifruit to enhance its shelf-life and marketability by approx. 6 d. 相似文献
6.
Summary‘Bartlett’ and ‘d’Anjou’ pears treated with 300 nl l –1 1-methylcyclopropene (1-MCP) did not soften to eating quality within 7 d, a desirable ripening period. A pre-conditioning method was evaluated as a means to re-initiate the softening ability of pears prior to marketing. Fruit were treated with 1-MCP and stored at –1°C in regular air, or in a controlled atmosphere for 2 – 9 months. After storage, fruit were pre-conditioned with nine temperature (10°, 15° or 20°C) and time (5, 10 or 20 d) combinations. Pre-conditioned fruit were then assessed for ripening ability following storage for 14 d at 20°C. The ripening ability of 1-MCP-treated ‘Bartlett’ fruit recovered in response to many pre-conditioning combinations of 10° – 20°C for 10 – 20 d, as indicated by a decrease in flesh firmness to 27 N or lower. The requirements for pre-conditioning regimes are storage atmosphere- and time-dependent. For ‘d’Anjou’ pears, no pre-conditioning combination resulted in re-initiating the ripening of fruit treated with 300 nl l –1 1-MCP. However, when the 1-MCP dose was 50 nl l –1, ‘d’Anjou’ pears ripened over an extended shelf-period with a substantial decrease in superficial scald. The results indicate that treatment with 1-MCP at approx. 50 nl l –1, combined with a pre-conditioning prior to marketing, is a potential means to control scald in ‘d’Anjou’ fruit. Re-initiation of ripening occurred concomitantly with a substantial increase in ethylene production. The control of superficial scald by 1-MCP in ‘d’Anjou’ pears was due to the inhibition of the biosynthesis of -farnesene and conjugated trienes. 相似文献
7.
The optimum storage and ripening temperature for the 2 cultivars was approximately 20°C. Both cultivars ripened earlier after exogenous application of C 2H 4 combined with the removal of CO 2. The storage life of the fruits could be extended by maintaining them in an atmosphere devoid of C 2H 4 but containing 5% (v/v) CO 2 and with a high relative humidity. Chilling-injuries occurred at temperatures below 15°C when the papayas were stored for more than 7 days. The nutritional value of ripe fruit decreased rapidly with prolonged storage. At the “eating-ripe” stage, the glucose, protein and ascorbic acid contents were 2.23 g, 209 mg and 33 mg per 100 g pulp in ‘Bentong’, and 2.15 g, 196 mg and 30 mg per 100 g pulp in ‘Taiping’, respectively. 相似文献
8.
SummaryExperiments were conducted to optimize nutritional and cultural requirements for initiation and growth of roots on papaya in vitro. Axillary shoots were obtained from plants which had been sub-cultured monthly for two years. Root initiation was enhanced when 1 to 2 mm of stem base was removed and shoots were growing actively before transfer to the rooting medium. Decreasing daylength during incubation from 24 h to 12 h promoted root initiation. Within the day temperature range of 22 to 29°C, optimum rooting occurred at 27°C and higher temperatures produced higher mean root weights per shoot. High concentrations of growth factors and the absence of sucrose in the medium both reduced root initiation, however, varying the concentration of sucrose and removing growth factors affected mean root weight per shoot. All media contained a modified de Fossard et al. (1974) basal medium plus 10 μM IBA. 相似文献
9.
SummaryThe present work investigated the effects of different aqueous extracts of organic waste compounds on growth, proliferation and photosynthetic activity in ‘M9’ ( Malus domestica Borkh.) shoot cultures, with the aim of determining the feasibility of using in vitro cultures as a tool for the rapid evaluation of organic amendments in agriculture. Aqueous extracts of the following organic waste compounds: cow manure (CM), sugarbeet industrial waste (SB), mixed grape, poultry and municipal solid waste (GPM), and citrus pruning and industrial waste (CPI) were prepared at a rate of 1:10 (w/v) compound:distilled water. The basal media used in the proliferation phase were: (i) PM1, modified Murashige and Skoog (MS) enriched with 4.4 µM 6-benzyladenine (BA); (ii) PM2, as PM1 but with a reduced cytokinin concentration (1 µM BA) to evaluate possible hormone effects; and (iii) PM3, 4.4 µM BA with reduced salt strength (0.33 MS) to induce nutrient deficiency. Hormone-free medium with half-strength MS salts was used for rooting. All media were enriched with each extract at 0, 0.2, 2, 20 or 200 ml l –1. Photosynthetic activity was measured on PM3 medium enriched with SB or CM. Standard culture conditions were 22° ± 2°C, with a 16 h photoperiod at 30 µmoles photosynthetically active radiation (PAR) m –2 s –1, but at 80 µmoles PAR m –2 s –1 to determine photosynthetic activity. Shoot weight increase in PM1 was not affected by the GPM and CPI extracts, while the growth trends of CM- and SB-treated shoots were described by a second-degree function with maxima at 2 ml l –1 and 0.2 ml l –1, respectively. Shoot proliferation for SB was represented by a quadratic curve (maximum at 2 ml l –1), was linearly reduced as GPM increased, but was not affected by CM or CPI. Treatments did not significantly affect rooting percentage and root length; however root number was increased by SB at 2 ml l –1.CO 2 fixation increased linearly with both SB and CM, despite reduced growth at the highest levels of extract. 相似文献
10.
‘Hamlin’, ‘Parson Brown’ and ‘Pineapple’ oranges were stored for 4 weeks at 15°C in a continuous flow of (1) air, (2) 20 mg 1 ?1 ethylene (C 2H 4) in air, (3) 40% O 2 + 60% N 2, or (4) 80% O 2 + 20% N 2, followed by 2 additional weeks in air. Fruits stored in the C 2H 4 atmosphere lost rind chlorophyll faster, and the rind turned orange quicker, than fruits in the other atmospheres. However, most of the fruits stored in the C 2H 4 atmosphere had paler endocarp and juice than fruits stored in the other atmospheres. Fruits stored in 80% O 2 had the palest rind, but their endocarp and juice color were the deepest orange. Color change was detectable after 2–3 weeks and continued to develop until the end of the experiments. In 40% O 2 fruit, response was intermediate.The respiration rate of ‘Pineapple’ oranges during 4 weeks of storage in the test atmospheres was highest in the fruits stored in C 2H 4, almost as high in fruits stored in 80% O 2, and lowest in fruits kept in 40% O 2 or in air. Fruits stored in the different atmospheres did not differ significantly in total soluble solids content, total acidity, or pH of the juice, and the atmospheres did not adversely affect the flavor of the juice. 相似文献
11.
The fruit characteristics and storage potential of some local and introduced mango cultivars grown in Trinidad were compared. At ambient temperature (28–32°C), fruit could be stored satisfactorily for between 3 and 8 days, after which ripening rapidly occurred. At 14°C, storage life was increased to as much as 18 days (cultivar ‘Graham’). Enclosure of fruits individually in polythene bags increased storage life at either ambient or 14°C temperature, while treatment with 3% Sta-fresh wax increased storage at ambient but not at 14°C. In the case of ‘Doodooth’, which was highly susceptible to anthracnose, treatment of fruit with hot water (52 ± 2°C) containing 500 or 1000 mg l ?4 benomyl for 5 min reduced the incidence of disease. Results are discussed in relation to the export potential of mangoes. 相似文献
12.
‘Alaska’ and ‘Redwing’ azaleas having dormant flower buds were sprayed with gibberellins (GA 3 or GA 4 + 7) alone and in combination with thiourea, N 6 benzyl adenine (BA) or kinetin weekly for 3 or 4 weeks to test the efficacy of these materials in breaking bud dormancy. Additional plants received 6 weeks of cold storage at 4.5°C or glasshouse day temperatures of 21°C and above. The 2000 and 3000 mg l ?1 GA 3 and Ga 4 + 7 sprays were better than 1000 mg l ?1 in promoting flowering, with ‘Redwing’ responding better than ‘Alaska’. GA-treated plants flowered in fewer days than those receiving cold storage. Flower diameter and pedicel length increased with higher levels of GA, and flower uniformity was comparable to cold-stored plants on most GA-treated ‘Redwing’-plants. Thiourea, BA and kinetin applied alone had no effect and considerable cytokinin activity was highest in GA-treated buds 14–21 days after treatment application. No increase in activity occurred on plants not receiving GA. 相似文献
13.
The study was carried out to determine the effect of melatonin on quality and postharvest life of sweet cherries (Prunus avium L.) cv. ‘Sweetheart’ during storage. The fruits were dipped at different concentrations of melatonin (0, 250, 500 and 1000?µmol l?1 for 10?min) and distilled water as control. The changes of sweet cherries were assessed at 7?day intervals by evaluating the following quality parameters: firmness, soluble solids content, titratable acidity, respiration rate, color values (L* and chroma), ascorbic acid content, total anthocyanin content, total phenolic content, and antioxidant activity. The results showed that increasing the dose to 1000?µmol l?1 melatonin had a remarkable effect on maintaining the quality of sweet cherry. 1000?µmol l?1 and 500?µmol l?1 melatonin treatments significantly inhibited the decrease in firmness, ascorbic acid, total phenols, total anthocyanin, antioxidant content and reduced color changes and respiration rate. However, the total soluble solids content and titratable acidity of the fruit were not influenced by melatonin applications. These findings indicate that melatonin treatment may be effective in maintaining quality and bioactive compounds of sweet cherry fruit. 相似文献
14.
A continuous supply of sucrose together with 8-hydroxyquinoline citrate to cut Lilium Asiatic hybrid ‘Prima’ inflorescences resulted in buds opening satisfactorily and increased their longevity. The best results were obtained using 30 g l ?1 sucrose. Cut Lilium inflorescences could be stored at 1°C for 4 weeks without a great loss in potential vase-life and decorative value when the inflorescences were pre-treated with silver thiosulphate + 100 g l ?1 sucrose for 24 h before cold storage, kept in a cold room in a solution containing 50 mg l ?1 silver nitrate, and after cold storage kept in a solution containing 30 g l ?1 sucrose and 200 mg l ?1 8-hydroxyquinoline citrate. Such treatment greatly improved bud opening, increased the diameters of individual flowers and prolonged their life. 相似文献
15.
SummaryGiant reed ( Arundo donax L.), a promising energy crop, is vegetatively-propagated from fragments of stems and rhizomes. This may limit large-scale cultivation, since it is time-consuming and involves considerable cost and effort. Tissue culture is an alternative to conventional methods of vegetative propagation and may represent a useful tool for large-scale propagation of plants for biomass production programmes. This report describes a protocol for the large-scale in vitro propagation of giant reed by adventitious bud formation. Stem nodes with dormant buds proved to be the most effective to initiate in vitro cultures giving the highest percentage of differentiated shoots (77%) compared to the other plant fractions tested. A sterilisation procedure using 5 g l –1 HgCl 2 enabled the production of sterile explants. Moreover, early results indicated that late Autumn excision dates not only gave a higher percentage of well-developed shoots ( > 80%), but also a lower level of bacterial contamination (15 – 20%). 6-Benzylaminopurine (BAP) at 3.0 mg l –1 was most effective in promoting shoot multiplication when added to a basal medium containing Murashige and Skoog (MS) macro- and micro-nutrients, Morel’s vitamins, 30 g l –1 sucrose, and 7.0 g l –1 bacteriological agar supplemented with 1.0 mg l –1 indole-3-acetic acid (IAA) and 0.05 mg l –1 gibberellic acid (GA 3). Rooting was successfully induced on the same basal medium used for proliferation, modified by halving the MS macro-nutrients and replacing BAP and the other growth regulators with 2.0 mg l –1 1-naphthaleneacetic acid (NAA). Successful acclimatisation (> 95% survival) of plantlets was carried out, even in late Winter, in a cold greenhouse or under simpler facilities such as shade nets. 相似文献
16.
Carnation flowers, cv White Sim, of three market grades from commercial-type beds were examined monthly to relate their grading to various quality parameters and to determine the extent of any seasonal changes in these values. Some showed small seasonal changes, e.g. percentage dry weights of flowers and stems, whereas others showed very large seasonal changes, e.g. flower diameter, stem strength and the proportion of the dry weight in the flower head relative to that in the stem. Regression analyses showed that flower fresh weight was related to the mean daily radiation and temperature integrals in the period from the early bud-visible stage to anthesis:Fresh weight (g)=5.022+10.537 log e cal cm- 2 day- 1-2.215 temp. °C.Stem strength was also related to radiation and temperature in this period:Stem strength (coded value)=34.825–9.027 log e cal cm- 2 day- 1+1.214 temp. °C.Unlike fresh weight and stem strength, in which solar radiation played a greater role than temperature, flower diameter was largely dependent upon temperature, high temperatures producing small flowers. Temperature and light integrals in the period from the early bud-visible stage to the bud reaching 1 cm diam. gave the best relationship to flower diameter at anthesis:Diameter (cm)=9.361–0.1567 temp. °C+0.1353 log e cal cm- 2 day- 1.The environmental conditions required to produce good quality carnation flowers were found to be high solar radiation integrals coupled with low ambient temperatures. 相似文献
17.
This study assessed the effect of phosphites (Mg, Zn, Ca, K) on papaya (‘Sunrise Solo’) anthracnose ( Colletotrichum gloeosporioides). Surface-sterilised wounded (2mm) fruits were inoculated (50µL; 10 6 con/mL) with C. gloeosporioides and then the products were applied. The lesion diameters (LD) and the physico-chemical properties were analysed. Assays in vitro and in vivo were carried out with phosphites. The results in vitro indicated that the phosphites were effective in reducing the mycelial growth and conidia production for all doses [Phosphite Mg – 0.75, 1.5, 3 ml/l (40% P 2O 5 + 6% Mg) Fitofos Mg; Phosphite Zn - 1.25, 2.5, 5 ml/l (40% P 2O 5 + 10% Zn)]; Phosphite Ca - 1.5, 3, 6 ml/l (30% P 2O 5 + 7% Ca)]; Phosphite K - 1.25, 2.5, 5 ml/l (40% P 2O 5 + 20% K 2O)]. Concentration experiments on disease control showed that Phosphite-Ca at 6 ml/l (30% P 2O 5 + 7% Ca) significantly reduced the LD. Fruit treated with phosphite-Ca maintained physico-chemical properties of papaya fruits. 相似文献
18.
Partly cooled (5°C) tulip ‘Apeldoorn’ were treated with gibberellins GA 3 and GA 4 + 7 by vacuùm infiltration, with a view to defining conditions suitable for exploiting the effects of GA on forced tulips (faster flowering, control of stem extension, reduction of floral bud blasting).The first experiment showed that GA 3 and GA 4 + 7 were equally effective in reducing the glasshouse period following 6 or more weeks cold storage; with less than 6 weeks cold storage, effects were less marked. Stem length at flowering was reduced by GA treatments, particularly by GA 3 and following more than 6 weeks cold storage. However, the vacuum infiltration method used (30 min at 10 torr) resulted in serious flower losses.Next, the effect of GA 3 concentration (up to 1500 mg 1 ?1) was studied using vacuum infiltration treatments for 1–15 min at 20–510 torr, which resulted in fewer flower losses. Following 4 weeks cold storage, reducing pressure or increasing GA 3 concentration reduced both glasshouse period and stem length, with no effect of duration of treatment; GA 3 concentration was the only factor affecting flower length, which was increased. Following 8 weeks cold storage, increasing GA 3 concentration, vacuum or duration reduced glasshouse period. With all 3 factors at their maximum levels, 16 days earliness was obtained compared with controls. With maximum earliness, stem length was reduced to about 23 cm, compared to about 26 cm for treatments giving about 1 week's earliness, and 32 cm for untreated controls. Increasing vacuum appeared the most economical way of obtaining earliness, 20 torr giving 7 days earliness even at only 250 mg GA 3 1 ?1. Treatments giving earlier flowering also gave larger flowers. For comparison, there was little effect of soaking bulbs at atmospheric pressure even at 500 mg GA 3 1 ?1 for up to 20 h.Further experiments, conducted with vacuum infiltration at 260 torr for 15 min, confirmed these GA effects using formulated GA 3 (as “Berelex”) and GA 4 + 7 (as “Regulex”). Effects of GA on stem length at flowering had disappeared by the time stems reached their final length. Comparisons with bulb injection of GA showed that this method required less GA than vacuum infiltration for similar effects, and that the greater effectiveness of GA 4 + 7 compared with GA 3 was less marked using vacuum infiltration. 相似文献
19.
SummaryDifferent concentrations of aminoethoxyvinylglycine (AVG) and gibberellic acid (GA 3) and their combinations, applied at two stages of fruit growth, were evaluated for prolonging the marketing season of `Feicheng' peaches. GA 3 applied at the end of pit hardening, or AVG applied two weeks before commercial harvest, inhibited fruit maturation on the tree, delayed harvest and reduced flesh browning after cold storage in a concentration-dependent manner. A synergistic effect was found when both GA 3 and AVG were used, with the combination of 100 or 150.mg l ±1 GA 3, applied at the end of pit hardening, and 100 mg l ±1 AVG, applied two weeks before harvest giving the best results. These combinations retarded the change in ground colour, loss of firmness, and reduction in acidity by 2±3 weeks. Since harvest was prolonged by 2±3 weeks, soluble solids content (SSC) in fruit increased compared with the control (harvested earlier). Fruit size was significantly greater on treated trees compared with the controls when fruit set was controlled to the same level by hand thinning. After four weeks of storage and 4.d at 208C, 83% of control fruit developed tissue browning, but only 5% of AVG + GA 3-treated fruit developed browning after six weeks of storage and 4 d at 208C. Thus, the marketing season of `Feicheng' peaches was prolonged by at least four weeks by 100 or 150 mg l ±1 of GA 3 and 100 mg l ±1 of AVG. Fruit treated with 150 mg l ±1 GA 3 plus 100 to 150 mg l ±1 AVG showed similar results but failed to ripen properly after cold storage. 相似文献
20.
Sambucus caerulea (elder) seeds did not germinate after 4°C cool treatments for up to 30 days, when monitored for a further 30 days at 21°C. When seeds were soaked for 24 h in gibberellic acid (GA 3) prior to and during cold treatment, germination percentage depended on GA 3 concentration and duration of cold treatment. The highest germination percentage was 55 (1000 mg l −1 GA 3 for 30 days at 4°C). When seeds were treated with ethephon at 0, 100 or 1000 mg l −1, no germination was recorded after a subsequent 30-day 4°C treatment. Ethephon added to GA 3 gave a strong interaction, leading to further promotion in germination. Optimal germination was obtained after 1000 mg l −1 GA 3 and 100 mg l −1 ethephon for 30 days at 4°C (69%).The addition of ethanol, acetone, dimethyl sulfoxide or polyethylene glycol to the GA 3 soak as infusion agents either reduced or did not change the germination percentage. 相似文献
|