采后核黄素处理对苹果青霉病及活性氧和苯丙烷代谢的影响

以“金冠”苹果果实为材料,采后用不同浓度核黄素溶液浸泡处理,研究其对损伤接种青霉(Penicillium expansum)果实的控制效果及果实苯丙烷代谢途径、活性氧代谢关键酶活性和产物含量的影响。结果表明,低浓度的核黄素处理可显著降低损伤接种P.expansum果实的病斑直径,其中以1.0 mmol/L核黄素处理效果最佳。同时,1.0 mmol/L核黄素处理显著提高了果实过氧化氢酶、抗坏血酸过氧化物酶、谷胱甘肽还原酶、苯丙氨酸解氨酶及过氧化物酶活性,促进了过氧化氢、总酚、类黄酮和木质素的积累。由此表明,采后核黄素处理通过激活苯丙烷途径和活性氧代谢诱导苹果对青霉病的抗性。     

青霉菌BX1吸附剂的成本控制

通过对青霉菌BX1吸附剂制备方式的研究,探讨了不同的培养基组成对青霉菌生长的影响,找出了合理的菌体培养方式,提高了青霉菌的转化率,降低了生产成本,改善了菌体的成球状态,实现了青霉菌BX1吸附剂的成本控制。     

Diversity and population dynamics of Penicillium spp. on apples in pre- and postharvest environments: consequences for decay development

Isolates of Penicillium spp. were collected regularly from 2001 to 2003 from the surfaces of apple fruit pre- and postharvest, and from the atmosphere of orchards and storage rooms in France. Penicillium spp. were not detected from the atmosphere of conventional orchards, while their density did not exceed 50 spores m⁻³ in the atmosphere of organically managed orchards. Penicillium spp. were seldom detected on apple surfaces in the orchard. The density of Penicillium on apples increased from 10 to 50 spores cm⁻² after 1 month in storage to 300–400 spores cm⁻² after 6 months. The level of airborne Penicillium increased by up to 2 × 10⁴ and 2·5 × 10³ spores m⁻³ within nondisinfected and previously disinfected warehouses, respectively. Penicillium expansum (30–62%) and P. solitum (6–45%) were the most prevalent species on apple or in storage rooms. Other species of Penicillium isolated included P. commune, P. verrucosum, P. chrysogenum, P. rugulosum and P. digitatum. Apple fruit were also surveyed for wounds and the number of open lenticels using the sulphur dioxide test. The incidence of wounding at harvest varied from 12 to 36%, depending on cultivar and locality. When apples were inoculated at harvest by either aqueous or aerial inoculum of P. expansum, the decay incidence was constantly higher than the incidence of wounding. The number of open lenticels per cm² of apple surface varied from 0·5 on cv. Boskoop to 4·4 on cv. Golden Delicious. An average of 13 and 2·1% of lenticels, respectively, were infected when they were inoculated by P. expansum and P. verrucosum. Cultivars of apple fruit that showed a greater number of open lenticels, combined with a large diameter varying from 100 to 200 µm, were more susceptible to P. expansum.     

溶磷真菌促进磷素吸收和作物生长的作用研究

在盆栽条件下,利用花生、玉米、油菜在3种不同磷水平的石灰性土壤上,采用土壤耗竭性连续种植的方法,研究了溶磷青霉菌P8对吸收土壤磷素和作物生长的影响。结果表明,3种土壤上接种青霉菌P8菌剂都能提高作物的吸磷量,其生物产量比不接种显著提高,且在有效磷低的土壤上其增产幅度大于有效磷高的土壤;接种青霉菌P8在一定程度上能缓解和改善低温对作物生长和磷素吸收的不良影响。无论在有效磷高还是低的土壤,青霉菌P8都具有活化土壤磷、提高土壤磷素的利用效率和促进作物苗期生长的作用。     

溶磷真菌液体培养条件下对磷矿粉的溶解效果

Rock phosphate （RP） is a low efficiency P fertilizer that is directly applied to the soil and can be solubilized by phosphate-solubilizing microorganisms （PSMs） in fermentation or soil conditions. This study investigated dynamic solubilization of 2 concentrations of rock phosphate in a liquid culture with different dosages of glucose by two fungal isolates,Aspergillus niger P39 and Penicillium oxalicum P66, from soybean and wheat rhizosphere soil. Although during the 20 day culture period A. niger P39 had a stronger ability to acidify the culture media than P. ozalicum P66, soluble P concentrations at glucose dosages of 30 and 50 g L^-1 with RP of 15 g L^-1 in the culture solution were much higher by P. oxalicum P66. The greater effectiveness of P. oxalicum P66 compared to A. niger P39 in the solubilization of RP was strongly associated with the production of organic acids. This study suggested that for RP solubilization the type rather than the concentration of PSM-produced organic acids was more important.     

Inter- and intraspecific feeding selectivity of Folsomia candida (Willem) (Collembola,Isotomidae) on fungi

Summary Selective grazing of fungi by soil microarthropods may affect decomposition rates of litter materials and the structure of microarthropod and fungal communities. We developed laboratory methods to assay feeding selectivity and investigated the preferences of the collembolan Folsomia candida on three fungi: Acremonium sp., Paecilomyces varioti, and Penicillium citrinum. F. candida showed stronger preference for Acremonium sp. than for P. varioti and P. citrinum. Oviposition site selection followed the same pattern. Actively metabolizing hyphae of Acremonium sp. and P. varioti were preferred over senescent hyphae, while spores of P. citrinum were preferred over active hyphae. If microarthropod preference for active hyphae is extensive, microarthropod regulation of decomposition could be more important than their biomass indicates. Furthermore, as the P. citrinum results indicate, mechanisms of microbial dissemination may include selective grazing.Contribution in part to International Symposium on Faunal Influences on Soil Structure, Edmonton, Alberta, Canada (11–13 June 1984), organized by W. B. McGill; and the annual meeting of the Ecological Society of America, Minneapolis, Minnesota (17–21 June 1985)     

茶皂素和噻菌灵混配对沙糖橘采后青绿霉菌的防治效果及品质的影响

为明确茶皂素和噻菌灵混配对柑橘青霉和绿霉病菌的抑制作用,采用菌丝生长速率法和共毒系数法测定了茶皂素、噻菌灵及其混剂对柑橘青霉和绿霉病菌的室内毒力以及增效比率(SR),同时测定了茶皂素与噻菌灵混剂对沙糖橘采后青绿霉菌的防治效果及其对贮藏品质的影响.结果表明,茶皂素与噻菌灵配比为8:2时对柑橘青霉和绿霉病菌具有显著的防治效...     

青霉菌对桃树铅胁迫的缓解效应

为了解青霉菌对植物吸收重金属元素铅的影响,把从土壤里分离到的具有铅富集能力的青霉菌(Penicillium Inordinate Arenicolasp.)接种到铅污染不同程度的土壤里,采用盆栽的方法观察这个菌株对毛桃(Prunuspersica L.Batsch)和大久保桃(Prunuspersica L.Batschcv.Okubao)铅胁迫的缓解效应。结果表明:(1)在接种青霉菌的土壤里生长的毛桃和大久保桃的根、茎、叶中铅累积量均比未接种青霉菌的低,茎叶中铅的分配率比未接种青霉菌的低;(2)接种青霉菌相对增加桃苗株高、叶绿素含量、硝酸还原酶及超氧化物歧化酶活性,降低叶片的细胞膜透性;随着土壤中铅胁迫强度的增加,接种青霉菌对增加桃树株高及改善叶片生理特性的效应递减;(3)两个桃树品种的上述生理性状受铅胁迫的影响及青霉菌的缓解效应存在品种间差异。     

青霉菌对桃树铅胁迫的缓解效应

为了解青霉菌对植物吸收重金属元素铅的影响,把从土壤里分离到的具有铅富集能力的青霉菌（Penicillium Inordinate Arenicolasp.）接种到铅污染不同程度的土壤里,采用盆栽的方法观察这个菌株对毛桃（Prunuspersica L.Batsch）和大久保桃（Prunuspersica L.Batschcv.Okubao）铅胁迫的缓解效应。结果表明：（1）在接种青霉菌的土壤里生长的毛桃和大久保桃的根、茎、叶中铅累积量均比未接种青霉菌的低,茎叶中铅的分配率比未接种青霉菌的低;（2）接种青霉菌相对增加桃苗株高、叶绿素含量、硝酸还原酶及超氧化物歧化酶活性,降低叶片的细胞膜透性;随着土壤中铅胁迫强度的增加,接种青霉菌对增加桃树株高及改善叶片生理特性的效应递减;（3）两个桃树品种的上述生理性状受铅胁迫的影响及青霉菌的缓解效应存在品种间差异。     

碱性脂肪酶酶解鲐碎肉脂肪的研究

采用扩展青霉（Penicillium expansum)PF868产生的碱性脂肪酶为酶源，酶解脱酯鲐碎肉，其最适条件为：32－34℃，pH9．3，酶活浓度40u/ml，碎肉的质量与酶液体积比为1g:5ml，脱脂时间50min。鲐碎肉的干基残脂率低于4．0％。