Integration of continuous biofumigation with Muscodor albus with pre-cooling fumigation with ozone or sulfur dioxide to control postharvest gray mold of table grapes

An integrated approach was evaluated that combined biological and chemical fumigation of table grapes to control postharvest gray mold caused by Botrytis cinerea. After fumigation of the grapes with ozone or sulfur dioxide during pre-cooling, the fruit were then exposed to continuous biofumigation by the volatile-producing fungus Muscodor albus during storage. Biofumigation was provided by in-package generators containing a live grain culture of the fungus. This grain formulation of M. albus survived the initial ozone or sulfur dioxide fumigation, but sulfur dioxide reduced its production of isobutyric acid, an indicator of the production of antifungal volatiles. Gray mold incidence was reduced among inoculated ‘Autumn Seedless’ grapes from 91.7 to 19.3% by 1 h fumigation with 5000 μL L^?1 ozone, and further reduced to 10.0% when ozone fumigation and M. albus biofumigation were combined. The natural incidence of gray mold among organically grown ‘Thompson Seedless’ grapes after 1 month of storage at 0.5 °C was 31.0%. Ozone fumigation and M. albus biofumigation reduced the incidence of gray mold to 9.7 and 4.4, respectively, while the combined treatment reduced gray mold incidence to 3.4%. The use of commercial sulfur dioxide pads reduced the incidence to 1.1%. The combination of ozone and M. albus controlled decay significantly, but was less effective than the standard sulfur dioxide treatments. Although less effective than sulfur dioxide treatment, ozone and M. albus controlled decay significantly, and could be alternatives to sulfur dioxide, particularly for growers complying with organic production requirements.     

Studies of postharvest berry abscission of ‘Kyoho’ table grapes during cold storage and high oxygen atmospheres

The effects of high O₂ on catabolic enzymes and anatomical structure in abscission zones, fruit detachment force (FDF), and berry drop of grapes were investigated. ‘Kyoho’ table grapes (Vitis vinifera x V. labrusca) were subjected to air or 80% O₂ at 0 °C in 95% relative humidity for 60 days. During storage, separation occurred at the berry-pedicel indentation and the abscission layer extended gradually from lateral phloem towards the whole phloem and pith, forming intercellular cavities and leading to berry drop. FDF declined steadily accompanied by an increase in berry drop. Grape abscission was correlated to the increases in activity of hydrolases, in particular cellulase (Cx) and polygalacturonase (PG), in abscission zones. In contrast to air storage, high O₂ inhibited Cx, PG and pectinesterase (PE) activity and the reverse for peroxidase (POD), decreased the degree of swelling and distorting of the abscission cell walls, and tended to keep berry adherence strength high and reduced berry drop. The inhibitory mechanism of high O₂ on berry drop possibly could be explained by the fact that disassembly of the abscission zone cells was delayed by a synergistic impact on degradation enzymes whose activities were affected by high O₂ levels.     

Control of postharvest rots of sweet cherries and table grapes with endophytic isolates of Aureobasidium pullulans

Fifty-one endophytic isolates of Aureobasidium pullulans were obtained from the flesh of sweet cherries and extensively screened to evaluate their biocontrol activity against postharvest rots of sweet cherries and table grapes. Preliminary analysis of all isolates by randomly amplified polymorphic DNA (RAPD) with three different primers showed the presence of a high genetic variability and enabled isolates not showing any genetic difference to be discarded. Thirty-five isolates with different RAPD electrophoresis patterns had a wide range of biocontrol activity against Botrytis cinerea and Monilinia laxa on single-wounded berries of sweet cherries and table grapes with a reduction of decay from 10 to 100%. Two isolates (533 and 547) significantly reduced B. cinerea on table grape berries also when applied 6, 12, and 24 h after the pathogen inoculation. In a 2-year period of investigation (1998–1999), a reduction of total rots ranging from 32 to 80% (sweet cherries) and from 59 to 64% (table grape) was achieved with isolates 533 and 547 applied after harvest. Preharvest applications of isolate 547 significantly reduced postharvest rots of sweet cherries and table grapes by 47 and 38%, respectively. On the whole, isolates 533 and 547 were more effective than A. pullulans L47, a biocontrol agent of postharvest diseases with a known activity. Population studies demonstrated that isolate 547 was able to survive under field conditions, to increase its population during cold storage, and to penetrate the flesh of sweet cherries when applied during flowering.     

Potential of the biopolymer chitosan with different molecular weights to control postharvest gray mold of tomato fruit

Gray mold caused by Botrytis cinerea (Pers.) is the most economically important postharvest disease of fruit and vegetables at harvest and during storage. Therefore the current study was conducted to investigate the effectiveness of chitosan with different molecular weights on gray mold in vitro and in vivo in tomato fruit (Solanum lycopersicum L. var. lycopersicum) stored at different temperatures. In an in vitro experiment, the results demonstrated that the antifungal activity increased as the chitosan molecular weight decreased. In an in vivo study, chitosan treatments significantly reduced fungal decay and all compounds with concentrations of 2000 and 4000 mg/L showed complete control of the fungus in wound-inoculated fruit. Chitosan with a molecular weight of 5.7 × 10⁴ g/mol was the most effective compound among those tested. The results also revealed that high chitosan concentrations correlated with low disease incidence regardless of storage conditions. In addition to the antifungal activity, chitosan had the potential for the elicitation of defense markers, including total soluble phenolic compounds, polyphenoloxidase (PPO) activity and total protein content. Chitosan treatment decreased the activity of PPO and enhanced total protein and phenolic compounds in wounded tomato fruit. These findings suggest that the effects of chitosan with different molecular weights on gray mold in tomato fruit may be associated with direct fungitoxic properties against the pathogen, and the elicitation of biochemical defense responses in fruit.     

Combination of postharvest antifungal chemical treatments and controlled atmosphere storage to control gray mold and improve storability of ‘Wonderful’ pomegranates

Common food additives (sodium bicarbonate (SB), sodium carbonate (SC), and potassium sorbate (PS)) were compared to the fungicide fludioxonil for the control of gray mold on California-grown ‘Wonderful’ pomegranates artificially inoculated with Botrytis cinerea and stored at 7.2 °C in either air or controlled atmosphere (CA, 5 kPa O₂ + 15 kPa CO₂) conditions. Fludioxonil was superior to other treatments. PS was the most effective additive. Synergistic effects between antifungal treatments and CA storage were observed. After 15 weeks of storage at 7.2 °C, the combination of PS treatment (3 min dip in 3% solution at 21 °C) and CA storage was as effective as the combination of heated fludioxonil (30 s dip in 0.6 g L⁻¹ of active ingredient at 49 °C) and air storage. Mixtures of PS with SB or SC did not improve the efficacy of either treatment alone. In tests conducted in commercial facilities, decay development and external and internal fruit quality were assessed on naturally infected pomegranates stored in either air or CA after application of a selected postharvest antifungal combined treatment (CTrt) integrating PS, SB + chlorine, and fludioxonil. CTrt was effective in controlling natural gray mold after 6 weeks of storage at 8.9 °C, but lacked persistence and it was not effective after 14 weeks. CA storage greatly enhanced decay control ability of CTrt. Skin red color was better maintained in CA-stored than in air-stored fruit. Juice color and properties (SSC, TA, and pH) were not practically affected by either postharvest treatment or storage condition. The integration of PS treatments with CA storage could provide an alternative to synthetic fungicides for the management of pomegranate postharvest decay.     

Extending the postharvest life of carnations with nitric oxide—comparison of fumigation and in vivo delivery

The ability of nitric oxide (NO) to extend the postharvest life at 20 °C of carnations (Dianthus caryophyllus L. cv. White-Sim) was investigated using delivery by gas-based fumigation and in vivo release via a solution containing the NO donor compound 2,2′-(hydroxynitrosohydrazino)-bisethanamine (DETA/NO). Treatment with NO gas in air at 1 and 5 μl l⁻¹ produced about a 30% increase in postharvest life while DETA/NO applied in solution at 10 mg l⁻¹ extended postharvest life by about 50% when dissolved in water. For flowers, use of solid delivery appears to offer a more convenient and more effective method of NO treatment than gaseous fumigation to extend postharvest life.     

Effects of elevated CO2 and/or ozone on nutrient concentrations and nutrient uptake of potatoes

Potato crops were grown at seven sites across Europe to test the effects of elevated atmospheric carbon dioxide and/or tropospheric ozone concentrations on growth, yield and various aspects of potato tuber quality within the framework of the EC funded programme Changing Climate and Potential Impacts on Potato Yield and Quality (CHIP). Field exposure systems were used to enrich the atmosphere in CO₂ and/or ozone. At five of the sites, nutrient element conconcentrations (macronutrients: nitrogen, phosphorus, potassium, calcium, magnesium, and micronutrients: mangenese, zinc, iron) in different parts of plants from the various treatments were analysed. Under elevated CO₂, nearly all nutrient elements tended to decrease in concentration. At maximum leaf area, a significant reduction was observed for the concentrations of nitrogen and potassium both in aboveground biomass and in tubers, and for calcium in tubers. Since CO₂ enrichment promoted early tuber growth, these effects could in part be attributed to tuber developmental stage. At maturity, potato grown under CO₂ enrichment exhibited significantly lower concentrations of nitrogen, manganese and iron in aboveground organs, and of nitrogen, potassium and magnesium in tubers which means a reduction of tuber quality. In contrast to CO₂, elevated ozone tended to increase tuber nutrient element concentrations. This was significant for nitrogen and manganese. CO₂ effects on tuber biomass increase were more pronounced than CO₂ effects on nutrient element decrease. Thus, the total amount of nutrient elements taken up by potato crops increased under elevated CO₂. Fertiliser practice in a future, CO₂-rich world will have to be adjusted accordingly.     

Influence of aqueous 1-methylcyclopropene concentration, immersion duration, and solution longevity on the postharvest ripening of breaker-turning tomato (Solanum lycopersicum L.) fruit

The influence of aqueous 1-methylcyclopropene (1-MCP) concentration, immersion duration, and solution longevity on the ripening of early ripening-stage tomato (Solanum lycopersicum L.) has been investigated. Tomato fruit at the breaker-turning stage were fully immersed in aqueous 1-MCP at 50, 200, 400 and 600 μg L⁻¹ for 1 min, quickly dried, and then stored at 20 °C. Ethylene production, respiration, surface color development, and rate of accumulation of lycopene and polygalacturonase (PG) activity were suppressed and/or delayed in fruit exposed to aqueous 1-MCP. Suppression of ripening was concentration dependent, with maximum inhibition in response to 1 min immersion occurring at concentrations of 400 and 600 μg L⁻¹. Climacteric ethylene peaks were delayed approximately 6, 7, and 9 d and respiration was strongly suppressed in fruit treated with aqueous 1-MCP at 200, 400, and 600 μg L⁻¹, respectively, compared with control fruit. Fruit firmness, lycopene content, PG activity, and surface hue of fruit treated at the three higher levels remained strongly suppressed compared with control. Skin hue values and pericarp lycopene content in response to treatment at the subthreshold 50 μg L⁻¹ provided evidence for differential ripening suppression in external versus internal tissues. Maximum delay of softening and surface color development in response to 50 μg L⁻¹ aqueous 1-MCP occurred following immersion periods of between 6 and 12 min. Factors affecting fruit penetration by aqueous 1-MCP and mechanisms contributing to recovery from 1-MCP-induced ripening inhibition are discussed.     

Influence of picloram and thidiazuron on high frequency plant regeneration in elite cultivars of wheat with long-term retention of morphogenecity using meristematic shoot segments

Meristematic shoot segments (MSSs) were used to develop an efficient and reproducible regeneration system via multiple shoot differentiation in two elite cultivars of winter wheal. Cylindrical basal shoot segments. 3 4 mm in length, were excised from seedlings derived from mature embryos that had been germinated directly on MS‐based medium containing growth regulators. These segments were further cultured on the same medium formulations. Out of 24 variations analysed, the combination of 2 mg1 4‐amino‐3.5,6‐trichloropicolinic acid (picloram) + 3 mg/1 thidiazuron (TDZ) was found to be the most effective in inducing clumps of multiple schools, buds with little callusing. Sectors of these clumps were (1) further multiplied by biweekly subculturing on 2 mg/l picloram + 2.5 mg/l TDZ leading lo highly differentiating green clusters of buds without loss of tnorphogenesis for more than 12 months so far. and without albinism, or (2) transferred to 0.1 nig I picloram + I mg/l TDZ for shoot development and elongation. The elongated shoots rooted on basal medium with 0.5 mg/l indole‐3‐butyric acid (IBA) were transferred to soil and showed normal growth and fertility. Both cultivars formed multiple schools ranging from 28 to 33 per responding MSS after 10 12 weeks.     

氮磷钾、灌水、喷洒杀菌剂对强筋小麦产量和品质的影响

2001~2004年连续4年在大田和池栽2种条件下研究主要栽培措施(氮磷钾、灌水和喷洒杀菌剂)对强筋小麦产量和品质的影响。研究结果表明,氮肥运筹以“前轻中重后补充”模式的产量品质俱佳;施用氮肥对强筋小麦的面团稳定时间有明显的正效应,对蛋白质、湿面筋有一定的正效应,尤其在肥力偏低的地块,施氮效果十分明显,而磷、钾肥对几项指标都有一定负效应;强筋小麦的品质指标有随灌水次数的增加而降低的趋势,产量和品质俱佳又节水的处理为小麦生育中期供水即浇拔节期水;喷洒杀菌剂可以显著提高子粒千粒重,喷洒1次杀菌剂对子粒品质无明显影响,喷洒3次子粒的品质有下降的趋势。     

Influence of Long-term Application of Sewage Sludge and Compost from Garbage with Sewage Sludge on Soil Fertility Criteria

In a long-term field experiment in progress since 1962 on a luvisol derived from loess the influence of increasing amounts of sewage sludge, garbage compost and farmyard manure on the N dynamic and microbiological soil characteristics was investigated.
The following results were obtained:
The application of the organic materials over a period of 24 years resulted in an increase of the total C and total N content of the soil. The increase was mostly pronounced in the plots treated with garbage compost. The higher total N content was caused by higher contents of hydrolyzable as well as non-hydrolyzable organic N compounds. The N mineralization potential of the soil was intensified by the application of all the different organic materials, especially by garbage compost and farmyard manure.
Dehydrogenase activity and soil respiration were positively influenced by all organic treatments with the highest effect in the soils with the highest C, contents.     

高产抗寒杂交稻新组合"金优554"的选育研究与应用

金优554系安顺市农科所用金23A作母本,自育恢复系安恢554作父本组配选育的高产、优质、适应性广、抗寒性强的中迟熟杂交水稻新组合.该组合在2001～2002年两年的贵州省杂稻迟熟A组区试中,平均较对照汕优63增产11.2%,在2002年的生产试验中,平均较对照增产21.9%.株高101.4cm,有效穗18.0万左右/667m2,穗实粒数125.2粒,全生育期145.2～152.5d,抗寒性较强,中抗稻瘟病、纹枯病.经稻米品质分析,该组合是适宜食品加工型的优质专用型稻米.2003年7月通过贵州省农作物品种审定委员会审定.该组合适于贵州海拔400～1 300m稻区作一季中稻种植.     

Modulatory effects of functional rice cultivars giant embryo and Aranghyangchal on the body weight and lipid metabolism in mice fed with a high fat diet

The effects of the functional rice cultivars giant embryo and Aranghyangchal on the body weight and lipid metabolism in male C57BL/6N mice under high fat diet conditions were investigated. The animals were randomly placed into four dietary groups: normal control (NC group), high fat (HF group), and high fat supplemented with giant embryo (HF-GE group) or Aranghyangchal (HF-AR group). After 8weeks, a marked increase in the body weight and plasma triglyceride and total cholesterol concentrations were found in the HF mice relative to the control group. However, the addition of the functional rice samples in the high fat diet reduced the body weight gain and significantly decreased the lipid levels through inhibition of lipogenesis and regulation of adipokine production. The results demonstrate that the functional rice grains giant embryo and Aranghyangchal may both be useful as biomaterials in the development of functional food with therapeutic potential against high fat diet-induced hyperlipidemia.     

铁处理有机物料接种蚯蚓对苹果根际和蚯蚓粪中有机酸的影响

以8年生红富士苹果树为试材,用不同形态、不同浓度的铁处理玉米秸秆接种蚯蚓,玉米秸秆被蚯蚓转化为蚯蚓粪后,研究对根际和蚯蚓粪有机酸的影响.苹果根际和蚯蚓粪中检测到的有机酸主要有草酸、苹果酸、酒石酸、琥珀酸和丙二酸,以草酸含量为高.没有用铁处理有机物料的根际有机酸高于用铁处理的,Fe3+处理有机物料的根际有机酸含量大于Fe2+处理,蚯蚓粪中的有机酸含量均以5 000 mg/kg浓度的铁处理最高.     

Minimally processed potatoes: Part 2. Effects of high oxygen partial pressures in combination with ascorbic and citric acid on loss of some quality traits

Sliced potatoes were stored in flexible packaging under different oxygen partial pressures (10, 55 and 100 kPa) after dipping treatments with ascorbic and citric acid at different concentrations. The levels of oxygen, ascorbic and citric acid were modulated according to a Central Composite Design. The response surface methodology allowed an assessment of the effects of these variables and their interactions on the respiration rate in a closed system, on the carbon dioxide accumulation rate and the volatile metabolites production inside flexible pouches. The results showed that the respiration rate did not increase in direct linear proportion to the oxygen partial pressure and there was no significant difference in respiration between 55 and 100 kPa, even though the respiration rate was higher at these super-atmospheric oxygen levels than at 10 kPa. Citric acid did not affect the respiration significantly, while the respiration rate increased with the increase in ascorbic acid concentration. However, at the highest level of ascorbic acid tested (5%), the respiration rate decreased. During storage in a high barrier plastic pouch, a higher CO₂ accumulation rate was generally observed under 55 kPa than under 10 and 100 kPa. High oxygen partial pressures (55 and 100 kPa) did not stop the production of hexanal but they had an inhibitory effect on the anaerobic volatiles production.