葡萄叶中总黄酮的提取工艺研究

目的：从葡萄叶中提取总黄酮。方法：采用正交试验法研究葡萄叶总黄酮的最佳提取工艺条件,考察了乙醇浓度、回流温度、回流时间及料液比四因素对葡萄叶总黄酮提取率的影响。结果：确立了葡萄叶总黄酮最佳提取条件为：45％的乙醇为溶剂、液料比为1：40、提取温度为60％、提取时间2h,在最佳工艺条件下葡萄叶总黄酮含量为5．329mg／g。     

葡萄园果蝇的发生及综合防治研究进展

果蝇因种类多、分布广、寄主广、繁殖力强,世代历期短,近年已成为葡萄的重要害虫之一。葡萄果蝇幼虫不仅蛀食果实,导致果实逐渐软化以致变褐色,还能导致微生物的二次侵染,诱发酸腐病,严重影响葡萄的品质和产量。现已发现危害葡萄的果蝇有7种,其中以黑腹果蝇为优势种,其次为斑翅果蝇和叔白颜果蝇。在山东地区,7月初是斑翅果蝇和叔白颜果蝇的发生高峰期,而黑腹果蝇发生高峰期为8-9月上旬。就不同葡萄品种来说,黑腹果蝇成虫对4个葡萄品种巨峰、马奶、无核白和红提的嗜好程度无显著差异,幼虫对红提的嗜好程度显著高于巨峰、马奶和无核白;斑翅果蝇和叔白颜果蝇对于金手指等早熟品种以及果皮较薄的葡萄品种具有更强的趋性。本文依据葡萄园主要果蝇的种类、生物特征、生活习性、发生规律和危害习性,并从农业防治、物理防治、化学防治和生物防治等方面总结分析了其综合防治措施,以期为葡萄园果蝇的可持续控制提供理论和技术支持。     

Leaf trichomes influence predatory mite densities through dispersal behavior

Habitat complexity can mediate interactions among predators and herbivores and influences arthropod population density and community structure. The abundance of many predatory mites (Acari: Phytoseiidae) is positively associated with abundance of non‐glandular trichomes. We hypothesized that (1) increasing the complexity (trichome density mimicked with cotton fiber patches) of the habitat that predatory mites encounter on leaves would reduce adult dispersal from plants, and (2) increasing habitat complexity would reduce the time that mites spend walking. Typhlodromus pyri Scheuten retention on plants increased linearly in the presence of trichome mimics; mites placed on plants lacking leaf trichomes showed a behavioral response that led to active dispersal. Phytoseiid retention increased with both fiber patch size and fiber density within patches. Moving fiber patches from the underside of the leaf to the upper leaf surface did not change phytoseiid retention but did alter egg distribution, suggesting trichomes do not exclusively influence phytoseiid behavior. Phytoseiid activity level as measured by the amount of time spent walking did not decrease with the addition of fibers. Overall, increasing habitat complexity in the form of non‐glandular trichomes strongly reduced T. pyri dispersal behavior; the predatory mites showed a consistent preference for complex trichome‐rich habitat that was manifest both rapidly and in absence of predators. Hence, the frequently observed pattern of population‐level accumulation of phytoseiids on trichome‐rich plants appears to be driven by a behavioral response to the presence and abundance of non‐glandular trichomes on the leaf surface manifested in the level of dispersal and/or retention. The primary implication of phytoseiid–habitat interactions for biocontrol programs is that where plants have no trichomes, T. pyri will not establish. Whether this behavioral response pattern is a general response of phytoseiids to leaf trichomes or varies with species is a question that remains unanswered.     

南方主要鲜食葡萄生长结实特性与温度关系的研究

对南方鲜食葡萄品种生长结实特性与温度关系的研究表明,各品种春梢生长与气温,尤其是有效积温的关系符合Y=aX³+bX²+cX三次方程.依据拟合方程得:生长速率最快的是巨峰,当有效积温达190.68℃时,温度每增加10℃新梢生长0.43433cm;生长速率最慢且对温度不敏感的是蜜香宝,有效积温高达367.19℃时,新梢生长速率仅为0.17150cm.对果实经济性状综合评价和品种优良特性的模糊评判表明,值得推广的品种有巨峰、京亚、藤稔、蜜香宝、龙宝;限制发展的品种有紫珍香;淘汰早生高墨、黑丰.     

Biocontrol potential of two novel grapevine associated Bacillus strains for management of anthracnose disease caused by Colletotrichum gloeosporioides

A study was conducted to identify bacterial antagonists for biological control of anthracnose which is one of the economically important diseases of grapes. In India, it is caused by Colletotrichum gloeosporioides. Two hundred and ninety-three bacteria were isolated from the grape ecosystem of 43 spatially distant vineyards in peninsular India. Of these, 25 bacteria substantially inhibited the radial growth of C. gloeosporioides in in vitro studies and 18 bacteria significantly reduced infections in vivo. Of these 18 bacteria, 5 and 3 bacteria also significantly reduced percent disease index (PDI) of downy and powdery mildew diseases, respectively. These bacteria were labelled as strains, DR-38, DR-39, TL-171, DRo-198, TS-204, TS-205, and DR-219, and were identified as Bacillus species based on morphological and molecular characterisation. Aqueous suspensions of all these strains applied as foliar sprays at 1×10⁸ cfu/ml on field grown vines significantly lowered the PDI and the AUDPC (area under disease progress curve) of anthracnose when compared with the untreated control, except DRo-198. Strains TS-204 and TL-171 recorded lower PDIs and AUDPC when compared with the other five strains, and TS-204 could effectively suppress ripe rot of berries, too, in vivo. Strains TS-204 and TL-171 are identified for biocontrol of anthracnose in grapes.     

Microsatellite DNA markers for Plasmopara viticola,the causal agent of downy mildew of grapes

Microsatellite loci were isolated from Plasmopara viticola (Oomycetes), the causal agent of downy mildew of grape, one of the most damaging fungal diseases of grapevine worldwide. Seven polymorphic loci were obtained from an enriched partial genomic library. A low genetic diversity was observed at all loci, with a mean observed allele number of 3.75 and an observed heterozygosity ranging from 0.074 to 0.547. Cross‐amplification tests on three closely related taxa indicated that two loci could be used in other Oomycetes species. These microsatellite loci were proved to be useful for population genetic analysis.     

Immunodetection of Botrytis-specific Invertase in Infected Grapes

Invertase (β-fructofuranosidase, EC 3.2.1.26) activity was shown to be stimulated in grape berries after infection with Botrytis cinerea . By using organism-specific extraction methods, evidence was found proving that both partners contribute to the increase in activity. Qualitative analysis of the extracts by SDS–PAGE showed a new invertase species in the botrytised material, with a molecular weight similar to that of Botrytis invertase (BIT). A method allowing the preparative isolation of homogeneous invertase from liquid cultures of B. cinerea in only three steps (ethanol precipitation, DEAE anion exchange and hydroxyapatite chromatography) with 50% recovery was developed. BIT appeared to be strongly glycosylated; interestingly, the amount of glycan seemed to vary and had a remarkable influence on the chromatographic behaviour of the enzyme. After chemical deglycosylation with TFMS, the BIT peptide was used for the production of polyclonal antibodies in chickens (anti-BIT-IgY). The antibodies recognised glycosylated as well as deglycosylated BIT, a partial denaturation of the protein being necessary for reaction. This indicates that the deglycosylation procedure had been successful and that the antibodies were in fact directed to the peptide moiety. However, after a short incubation at 70°C, native BIT was detectable by anti-BIT-IgY, while still active. Western blotting with extracts of diseased berries confirmed the fungal origin of the new invertase form. The anti-BIT-IgY proved highly specific, although some cross-reaction with a protein in Monilia laxa extracts occurred. The importance of careful immunogen preparation in the production of specific antibodies, and the potential of BIT as a target molecule for the immunological detection of B. cinerea are discussed.