葎草对植物种子萌发和幼苗生长的影响

[目的]探讨葎草在生长过程中对其他植物的影响。[方法]采用培养皿滤纸法,研究葎草水浸提液对番茄、矮脚黄、莴苣种子萌发和幼苗生长的影响。[结果]葎草水浸提液对3种植物种子终萌发率的影响是有差异的,对番茄种子萌发没有明显影响,对矮脚黄、莴苣的影响较显著,而且地上部浸提液对矮脚黄种子萌发抑制作用较地下部强,而地下部浸提液对莴苣萌发的抑制作用较地上部明显。葎草不同部位浸提液对3种植物根长和苗长生长的影响趋势是一致的,不同处理浓度,抑制根长生长,而刺激苗长生长。[结论]该研究为农业生产和植物源除草剂的研究提供了理论依据。     

Crop damage caused by powdery mildew on hop and its relationship to late season management

Powdery mildew of hop (Podosphaera macularis) may cause economic loss due to reductions in cone yield and quality. Quantitative estimates of crop damage from powdery mildew remain poorly characterized, especially the effect of late season disease management on crop yield and quality. Field studies in Washington State evaluated cone yield, bittering acid content and quality factors when fungicide applications were ceased at different stages of cone development. The incidence of cones with powdery mildew was linearly correlated with yield of cones, bittering acids and accelerated cone maturation. In cultivar Galena, the cumulative effect of every 1% increase in cones powdery mildew incidence was to reduce alpha‐acid yield by 0·33%, which was due to direct effects on cone yield but also indirect effects mediated by dry matter. In the more susceptible cultivar Zeus, alpha‐acid yield was increased 20% by controlling powdery mildew through the transition of bloom to early cone development compared to ceasing fungicide applications at bloom: additional applications provided only modest improvements in alpha‐acid yield. In both cultivars, the impact of powdery mildew on aroma characteristics and bittering acid content were less substantial than cone yield. The damage caused by powdery mildew to cone colour and alpha‐acid yield, as well as the effectiveness of fungicide applications made to manage the disease, appears inseparably linked to dry matter content of cones at harvest. Realising achievable yield potential in these cultivars requires control of the disease through early stages of cone development and harvest before maturity exceeds c. 25% dry matter.     

鸡矢藤的扦插繁殖技术研究

为了降低鸡矢藤扦插育苗的成本,促进其在公路边坡防护中的推广应用,以1a生鸡矢藤成苗的插条为试验材料,分别进行不同基质、不同插穗部位、不同芽节数、不同制穗方式、不同扦插方式、不同种类及浓度植物生长调节剂的扦插试验,对其扦插繁殖技术进行研究,结果表明:鸡矢藤生长最适条件为沙壤土、中部插穗、1个芽节或2个芽节、斜切或平切、斜插方式;植物生长调节剂ABT1、NAA、IBA浓度分别为350mg/L、100mg/L、100mg/L时插条的生根率和成活率最高,均分别为83%、87%和86%。     

鸡屎藤地上部分化学成分的初步研究

通过系统预试和单项预试，初步确定鸡尿藤地上部分含有酚类，有机酸，生物碱，氨基酸、多肽（或蛋白质）、糖、多糖（或甙类）、黄酮及其甙类、甾醇（或三萜）和挥发油等成分。     

Effect on Humulus scandens Alcohol Extract on Secretory Diarrhea of mice

To explore the therapeutic effect of Humulus scandens alcohol extract on secretory diarrhea in mice,we used lavage of senna to produce diarrhea mice mode.The mental state,body weight,colon intestinal wall thickness and histopathological changes were observed daily during the experiment period and the disease activity index was detected to evaluated therapeutic action of Humulus scandens alcohol extract on diarrhea.The results showed that compared with model group,the treatment group had significant effects on metal state,body weight and small intestinal villus recoveries;Compared with model group,body weight of treatment group had a rising trend but still couldn't reach the normal level.The DAI of treatment group decreased compared with model grope,there was no significant difference between blank group and treatment group (P>0.05).Compared with model group,intestinal wall thickness of treatment group were significant differences (P<0.05),the treatment effect was remarkable.Histological examination showed that in blank group,small intestinal villus was neatly,the hierarchical structure was clear,and there was no small vessel hyperemia and no villous intestinal edema.While small intestinal villus of model group disordered,most of the villus fell off,there was inflammation exudation on the surface of villi,villous edema and congestion of small blood vessels.Compared with model group,symptoms of treatment group significantly changed,which showed greatly reduced cell inflammatory exudation,there was no obvious edema and congestion in villi interstitial,small intestinal structure was roughly the same as normal tissue,the treatment effect was obvious.Humulus scandens alcohol extract had significant therapeutic effect on diarrhea in mice,and could provide a theoretical basis for the treatment of secretory diarrhea.     

PCR detection of Pseudoperonospora humuli in air samples from hop yards

Downy mildew of hop, caused by Pseudoperonospora humuli , is an important disease in most regions of hop production and is managed largely with regular fungicide applications. A PCR assay specific to P . humuli and the related organism P .  cubensis was developed and used to monitor airborne inoculum in hop yards to initiate fungicide applications. The PCR amplified as little as 1 fg of genomic DNA of P . humuli , and yielded an amplicon in 70% of reactions when DNA was extracted from single sporangia. In the presence of 25 mg of soil, an amplicon was amplified in 90% of reactions when DNA was extracted from 10 or more sporangia. During nine location-years of validation, PCR detection of the pathogen in air samples occurred no later than 8 days after the appearance of trace levels of disease signs and/or detection of airborne spores in a volumetric spore sampler. Inoculum was detected on average 4·5 days before (range −8 to 14 days) the first appearance of basal spikes in six commercial yards, or 1·3 days after (range −5 to 1 days) sporangia were detected in a volumetric spore sampler in experimental plots. In commercial yards, use of PCR to initiate the first fungicide application led to enhanced disease control or a reduction in fungicide use in four of six yards compared to growers' standard practices. These results indicate that the efficiency and efficacy of hop downy mildew management can be improved when control measures are timed according to first detection of inoculum.     

Contact and ingestion toxicities of plant extracts to <Emphasis Type="Italic">Thaumetopoea solitaria</Emphasis> Frey. (Lepidoptera: Thaumetopoeidae)

Thaumetopoea solitaria is a serious pest of pistachio throughout the Mediterranean and the surrounding region. In this study, contact and ingestion toxicities of Bifora radians, Fumaria officinalis, Humulus lupulus and Rhododendron ponticum extracts against T. solitaria larvae were examined under laboratory conditions. Dimethoate was used as a positive control. In the contact toxicity bioassays B. radians extract was the most toxic, causing 32% mortality. In the ingestion toxicity bioassays H. lupulus extract was the most active, causing 83% mortality after 48 h. This shows that H. lupulus is acting as a stomach poison. The LC₅₀ and LC₉₀ values for H. lupulus ingestion toxicity bioassays were 1.7 and 8.7%, respectively. The LT₅₀ value was 29.3 h. Since H. lupulus extract caused >50% mortality even 6 days after application, its long lasting residual effect promises fewer applications. These results imply that H. lupulus has potential for use as a crop protectant against T. solitaria.     

Genetic structure and differentiation in hop (Humulus lupulus L.) as inferred from microsatellites

A set of 67 wild and cultivated hop accessions, representative of hop diversity, was genotyped with 29 SSR markers in order to investigate the population structure and genetic diversity among hop genotypes. A total of 314 alleles was detected, with an average of 10.8 alleles per locus and an average PIC content of 0.607. Model-based clustering placed the accessions into five germplasm groups. A distance-based tree showed good agreement with five germplasm groups, and additionally assigned accessions omitted from model-based analysis into two additional germplasm groups. The 67 hop accessions were thus subdivided in seven germplasm groups, with three corresponding to major breeding groups and four to wild hops. This finding is in accordance with two biogeographically separated hop germplasms (European and North American origin) and with the known history of the accessions. North American hop germplasm was partitioned into native and cultivated germplasm groups. European germplasm was divided into two groups of hop cultivars representing distinguishable European germplasms and three new groups of native hops, which were differentiated for the first time by this analysis. Admixture analysis showed shares of various ancestries in hop cultivars, mostly congruent with pedigree data, and the introgression of various ancestries in some native hops. The above results have so far given the most detailed insight to date into the population structure of hop diversity, which is important for its effective use in hop breeding.     

千里光的化学成分鉴定及体外抗菌试验

用分项试管预试法和圆形滤纸层析法对千里光的化学成分进行了检验;进行了千里光全草水煎剂及贡酮提取物的体外抗菌试验,结果表明,千里光全草含有黄酮及其甙类,酚性物质,鞣质,挥发油及生物碱等化学成分;千里光全草及其黄酮提取物对金黄色葡萄球菌,大肠埃希氏菌,肠炎沙门氏菌,炭疽杆菌,溶血性链球菌均有明显的抗菌作用。     

Male and female genetic linkage map of hops, Humulus lupulus

A male and female linkage map of hop has been constructed using 224 DNA polymorphisms (106 amplified fragment length polymorphisms (AFLPs), three random amplified polymorphic DNAs (RAPDs), one RAPD‐sequence‐tagged‐site (STS), and three microsatellite (STSs) segregating in an F₁ population of the English cultivar ‘Wye Target’‐the German male breeding line ‘85/54/15’. Linkage between these loci was estimated using JOINMAP Version 2.0. The final map for the female parent consisted of 110 loci assigned to eight linkage groups covering a distance of 346.7 cM. For the male map, 57 loci could be mapped on nine linkage groups spanning over 227.4 cM. One of these male linkage groups (Gr09‐M) presumably represents the Y chromosome, since all markers assigned (10 AFLPs, three RAPDs and one STS) were closely linked to the male sex (M). Because of their sex‐specific segregation, 10 doubly heterozygous AFLPs spanning a distance of 18.7 cM could be identified as markers describing the X chromosome, which is part of the male and female map. Three STMSs, which had already proved useful in hop genotyping, could be integrated as codominant locus‐specific markers and thus allowed to produce reliable allelic bridges between the female and male counterparts.