Aphidophagous guilds on nettle （Urtica dioica） strips close to fields of green pea, rape and wheat

The common nettle （Urtica dioica L.） is a perennial and cosmopolitan plant species and is known to be the source of food for a great diversity of insects. To understand the importance of the nettle in agro-ecosystems, a field experiment was carried out in an experimental farm at Gembloux （Belgium） to study the effect of nettle margin strips on aphid and aphidophagous populations in close field crops, namely wheat （Triticum aestivum L.）, green pea （Pisum sativum L.） and rape （Brassicae napus L.）. The aphids and related beneficial populations were weekly assessed, from March to August 2005, by visual observations in two plots per field crop. A higher abundance of aphidophagous beneficials was collected in nettle strips when compared to the field crops. Particularly, the presence of predatory anthocorids, mirids and green lacewings was observed on nettle only. Nevertheless, the most abundant aphid predatory family, the Coccinellidae, was distributed in both environments, in nettle strips and in crop fields. The field margin supported a significantly higher density ofHarmonia axyridis than the field crops. In contrast, the field crops, green pea particularly, supported a higher density of Coccinella septempunctata. The distribution of the aphidophagous species, mainly the ladybirds, was discussed in relation to the host plant and related aphid species and their potential effect on integrated pest management.     

Impact of climate warming on crop planting and production in Northwest China

One major challenge in agro-meteorological research is to accurately predict the impacts of global climate warming on future agricultural production. So the effects of climate warming over the past decades need to be assessed. We analyzed the effects of climate warming on crop planting, structure and yield in 5 northwestern provinces of China with a focus on Gansu Province, utilizing accumulated temperature (≥ 10°C, AT), accumulated negative temperature (< 0°C, ANT) and crop data collected from 1981 to 2003. The analysis led to the following conclusions: 1) climate warming is the main driving force for the expansion of winter wheat toward the north and the west in China, for the rapid increase in cotton planting acreage, and for the expansion of annually multi-crop areas toward the north in China and higher altitude; 2) Climate warming is the direct cause for early seeding of spring crops, prolonged growth duration for thermophilic crops and shortened growth duration for overwinter crops; 3) Climate warming is largely attributed to the dramatic increase in cotton yield.     

Forest carbon budgets in Southeast Asia following harvesting and land cover change

Terrestrial ecosystems play an important role in the global carbon (C) cycle. Tropicalforests in Southeast Asia are constantly changing as a result of harvesting and conversion to otherland cover. As a result of these changes, research on C budgets of forest ecosystems has intensi-fied in the region over the last few years. This paper reviews and synthesizes the available infor-mation. Natural forests in SE Asia typically contain a high C density (up to 500 Mg/ha). Logging activities are responsible for at least 50% decline in forest C density. Complete deforestation (conversion from forest to grassland or annual crops) results in C density of less than 40 Mg/ha. Conversion to tree plantations and other woody perennial crops also reduces C density to lessthan 50% of the original C forest stocks. While much information has been generated recently, there are still large gaps of information on C budgets of tropical forests and its conversion to otherland uses in SE Asia. There is therefore a need to intensify research in this area.     

Patterns of tree phenological diversity in dry tropics

Recent phenological studies in tropical deciduous forests revealed a mosaic of vegetation composed of several pheno-phases that are evolved as an adaptation by the species to overcome seasonal drought in different ways. These pheno-phases represent extent of annual deciduousness (～leaflessness) and triggering factors for buds break (e.g. vegetative and flower). Thus, studying patterns of various pheno-phases (phonological diversity) in tropical forest have been thought to provide a potential tool to address critical questions related to climate change modeling and monitoring. In tropics, tree species represent a gradient of deciduousness (from leaf-exchanging species to >6 months deciduous species) and flowering initiation (breaking of flower buds in various part of annual cycle). Both processes are mostly triggered by variation in day length and/or temperature during late dry season/autumn, and/or first significant rain during rainy season. In addition, few factors like drought induced leaf fall and sporadic winter rains are supposed to affect these processes temporarily. Besides, the abundances of pheno-phases (i.e. leafing and flowering) also vary among tropical deciduous forest trees. Presence of such variations in tropical tree pheno-phases and their abundances are reported to vary due to micro-climatic variables and has specific implications in tropical forests. Present paper discusses the existing information on various pheno-phases and their abundances in tropical forests and role of climatic factors on tree phonological diversity. Further, we emphasized the need to develop predicting understanding of impending climatic change (i.e. precipitation and temperature) on diversity of pheno-phases by collecting long-term data on tree pheno-phases through a network of phonological stations in dry tropics.     

Patterns of tree phenological diversity in dry tropics

Recent phenological studies in tropical deciduous forests revealed a mosaic of vegetation composed of several pheno-phases that are evolved as an adaptation by the species to overcome seasonal drought in different ways. These pheno-phases represent extent of annual deciduousness (～leaflessness) and triggering factors for buds break (e.g. vegetative and flower). Thus, studying patterns of various pheno-phases (phonological diversity) in tropical forest have been thought to provide a potential tool to address critical questions related to climate change modeling and monitoring. In tropics, tree species represent a gradient of deciduousness (from leaf-exchanging species to >6 months deciduous species) and flowering initiation (breaking of flower buds in various part of annual cycle). Both processes are mostly triggered by variation in day length and/or temperature during late dry season/autumn, and/or first significant rain during rainy season. In addition, few factors like drought induced leaf fall and sporadic winter rains are supposed to affect these processes temporarily. Besides, the abundances of pheno-phases (i.e. leafing and flowering) also vary among tropical deciduous forest trees. Presence of such variations in tropical tree pheno-phases and their abundances are reported to vary due to micro-climatic variables and has specific implications in tropical forests. Present paper discusses the existing information on various pheno-phases and their abundances in tropical forests and role of climatic factors on tree phonological diversity. Further, we emphasized the need to develop predicting understanding of impending climatic change (i.e. precipitation and temperature) on diversity of pheno-phases by collecting long-term data on tree pheno-phases through a network of phonological stations in dry tropics.     

Domestication and crop evolution of wheat andbarley: Genes,genomics, and future directions

Wheat and barley are two of the founder crops of the agricultural revolution that took place 10,000 years ago in the Fertile Crescent and both crops remain among the world's most important crops. Domestication of these crops from their wild ancestors required the evolution of traits useful to humans, rather than survival in their natural environment. Of these traits, grain retention and threshability, yield improvement, changes to photoperiod sensitivity and nutritional value are most pronounced between wild and domesticated forms. Knowledge about the geographical origins of these crops and the genes responsible for domestication traits largely pre-dates the era of nextgeneration sequencing, although sequencing will lead to new insights. Molecular markers were initially used to calculate distance(relatedness), genetic diversity and to generate genetic maps which were useful in cloning major domestication genes. Both crops are characterized by large,complex genomes which were long thought to be beyond the scope of whole-genome sequencing. However, advances in sequencing technologies have improved the state of genomic resources for both wheat and barley. The availability of reference genomes for wheat and some of its progenitors,as well as for barley, sets the stage for answering unresolved questions in domestication genomics of wheat and barley.     

Nucleopolyhedrovirus Introduction in Australia

Nucleopolyhedrovirus (NPV) has become an integral part of integrated pest management (IPM) in many Australian agricultural and horticultural crops. This is the culmination of years of work conducted by researchers at the Queensland Department of Primary Industries and Fisheries (QDPI&F) and Ag Biotech Australia Pty Ltd. In the early 1970’s researchers at QDPI&F identified and isolated a virus in Helicoverpa armigera populations in the field. This NPV was extensively studied and shown to be highly specific to Helicoverpa and Heliothis species. Further work showed that when used appropriately the virus could be used effectively to manage these insects in crops such as sorghum, cotton, chickpea and sweet corn. A similar virus was first commercially produced in the USA in the 1970’s. This product, Elcar?, was introduced into Australia in the late 1970’s by Shell Chemicals with limited success. A major factor contributing to the poor adoption of Elcar was the concurrent enormous success of the synthetic pyrethroids. The importance of integrated pest management was probably also not widely accepted at that time. Gradual development of insect resistance to synthetic pyrethroids and other synthetic insecticides in Australia and the increased awareness of the importance of IPM meant that researchers once again turned their attentions to environmentally friendly pest management tools such NPV and beneficial insects. In the 1990’s a company called Rhone-Poulenc registered an NPV for use in Australian sorghum, chickpea and cotton. This product, Gemstar?, was imported from the USA. In 2000 Ag Biotech Australia established an in-vivo production facility in Australia to produce commercial volumes of a product similar to the imported product. This product was branded, ViVUS?, and was first registered and sold commercially in Australia in 2003. The initial production of ViVUS used a virus identical to the American product but replicating it in an Australian Helicoverpa species, H. armigera. Subsequent research collaboration between QDPI&F and Ag Biotech reinvigorated interest in the local virus strain. This was purified and the production system adapted to produce it on a commercial scale. This new version of ViVUS, which was branded ViVUS Gold?, was first registered and sold commercially in 2004. Widespread insect resistance to insecticides and a greater understanding of integrated pest management is leading to increased adoption of technologies such NPV in Australian agriculture.     

Balanced nitrogen economy as a flexible strategy on yield stabilizing and quality of aquatic food crops in wetland ecosystem

In wetland ecosystem, nitrogen along with other elements and its management is most imperative for the production of so many aquatic food, non-food and beneficial medicinal plants and for the improvement of soil and water characteristics. With great significant importance of INM (integrated nutrient management) as sources, emphasizing on management on nitrogen as a key element and its divergence, a case study was undertaken on such aquatic food crops (starch and protein-rich, most popular and remunerative) in the farmers' field of low-lying 'Tal' situation of New Alluvial Zone of Indian subtropics. The study was designed in factorial randomized block design, where, three important aquatic food crops (water chestnut (Trapa bispinosa Roxb.), makhana (Euryale ferox Salisb.) and water lily (Nymphaea spp.) as major factor and eleven combinations of organic and inorganic sources of nutrients as sub-factor was considered in the experiment. It revealed from the results that the production of fresh kernels or nuts of water chestnut (8.571 ha-1), matured nut yield of makhana (3.06 t ha-1) and flower stalks of water-lily as vegetables (6.38 t ha-1) including its nutritional quality (starch, protein, sugar and minerals) was remarkably influenced with the application of both organic (neem oilcake @ 0.2 t ha-1) and inorganic sources (NPK @ 30:20:20 kg ha-1 along with spraying of NPK @ 0.5% each over crop canopy at 20 days interval after transplanting) than the other INM combinations applied to the crops. Among the crops, highest WCYE (water chestnut yield equivalence) exhibited in makhana due to its high price of popped-form in the country, which is being exported to other countries at now. Sole application of both (organic and inorganic sources) with lower range did not produce any significant outcome from the study and exhibited lower value for all the crops. Besides production of food crops, INM also greatly influenced the soil and water characterization and it was favourably reflected in this study. The physico-chemical characteristics of soil (textural class, pH, organic carbon, organic matter, ammoniacal nitrogen, nitrate nitrogen, available nitrogen, phosphorus and potassium) are most important and contributed a significant improvement due to cultivation of these aquatic crops. Analysis of such wet bodies represented the water characteristics (pH, BOD, COD, CO3 =, HCO3-, NO3- N, SO4-S and Cl-) were most responsive, adaptable and quite favourable for the cultivation of these crops in this vast waste unused wetlands for the mankind without any environmental degradation.     

Progress in TILLING as a tool for functional genomics and improvement of crops

Food security is a global concern and substantial yield increases in crops are required to feed the growing world population. Mutagenesis is an important tool in crop improvement and is free of the regulatory restrictions imposed on genetically modified organisms. Targeting Induced Local Lesions in Genomes(TILLING), which combines traditional chemical mutagenesis with high‐throughput genome‐wide screening for point mutations in desired genes, offers a powerful way to create novel mutant alleles for both functional genomics and improvement of crops. TILLING is generally applicable to genomes whether small or large, diploid or evenallohexaploid, and shows great potential to address the major challenge of linking sequence information to the function of genes and to modulate key traits for plant breeding. TILLING has been successfully applied in many crop species and recent progress in TILLING is summarized below, especially on the developments in mutation detection technology, application of TILLING in gene functional studies and crop breeding. The potential of TILLING/EcoTILLING for functional genetics and crop improvement is also discussed. Furthermore, a small‐scale forward strategy including backcross and selfing was conducted to release the potential mutant phenotypes masked in M2(or M3) plants.     

Plant synthetic epigenomic engineering for crop improvement

Efforts have been directed to redesign crops with increased yield, stress adaptability, and nutritional value through synthetic biology—the application of engineering principles to biology. A recent expansion in our understanding of how epigenetic mechanisms regulate plant development and stress responses has unveiled a new set of resources that can be harnessed to develop improved crops, thus heralding the promise of “synthetic epigenetics.” In this review, we summarize the latest advances in e...     

Laboratory evaluation of the toxic properties of forest anchomanes, Anchomanes difformis against pulse beetle Callosobruchus maculatus （Coleoptera： Bruchidae）

Laboratory experiments were carried out to investigate the efficacy of crude stem extracts of forest anchomanes, Anchomanes difformis （P. Beauv.） a plant occurring in West African forests, against the pulse beetle Callosobruchus maculattts （Fabricius）. Crude stem extracts at 3% concentration showed high contact toxicity to adult beetles within 24 h after application, while it was moderately toxic to the beetles at the lowest （1%） concentration. At the highest application rate, the plant extract provided good protection to grains stored for 90 days. Grain viability and water absorption capacity were not affected by treatments with ethanol extracts ofA. difformis. The significance of these findings is discussed in relation to biopesticide-means of controlling cowpea bruchids.     

Allelopathic potential of Zilla spinosa on growth of associate flowering plants and some rhizosphere fungi

Zilla spinosa plant part extracts exhibited significantly different inhibitory effect on the seed germination and seedling growth of its associate species. Shoot extract reduced the percentage germination and seedling length of different test species more than root extract. Except of Z. coccineum, seedling growth was more sensitive than seed germination. Shoot/root ratio of all test species increased significantly with increase in extract concentration. Mycelia growth of the two rhizosphere fungal species was more significantly reduced by Z. spinosa shoot extract than root extract. The effects of the different extracts on total protein and total carbohydrate contents of the two test species were comparable. Non-significant increase was recorded at low concentration of both shoot and root extract. However, with the rise of extract concentration, highly significant reduction in the content of these metabolites was recorded. This revised version was published online in July 2006 with corrections to the Cover Date.     

大籽蒿花中生物碱类化感物质对羊草根茎节器官分化的影响

通过观察大籽蒿花提取物中生物碱物质对羊草根茎节部的影响 ,从细胞水平分析研究了它们之间的化感作用机制。结果表明 ,在有生物碱类物质存在时 ,与对照相比较 ,无论是羊草不定根的形成个数 ,还是从髓射线部位形成的突起物的个数 ,随浓度升高 ,存在一个先增加后降低的趋势。在浓度 1%下 ,影响不大 ;在 5 %和 10 %下 ,有增加的趋势 ;但随着浓度的增加 ,在浓度 2 0 %下 ,有减少的趋势。羊草根茎节部不定芽的形成个数受生物碱类物质的影响很小。     

Antimicrobial effects of Piper guineense 'Uziza' and Phyllantus amarus 'Ebe-benizo' on Candida albicans and Streptococcus faecalis

Two pathogens were employed, Streptococcus faecalis and Candida albicans for the study of the antimicrobial effects of Piper guineense and Phyllantus amarus using agar-well diffusion and disc-diffusion methods. Phytochemical screening of ethanol, cold and hot water extracts detected the presence of tannins, saponins, flavonoids, terpenoids and phlobatannins. Antimicrobial effect of the plant extracts showed that the organic solvent and aqueous solvents of P. amarus were inhibitory to S. faecalis while the extracts of Phyllantus amarus were not inhibitory to Candida albicans. Agar-well determined Minimum Inhibitory Concentration (MIC) values ranged between 3.125 mg/ml and 6.25 mg/ml while the disc diffusion determined MIC values ranged between 6.25 mg/ml and 25.0 mg/ml. The agar-well determined MIC values for the ethanolic P. amarus extracts (3.12 mg/ml) were lower than the corresponding disc-diffusion MIC determined values (6.25 mg/ml-25.00 mg/ml). Bacteriocidal and bacteriostatic effect varied with, solvent type of extract, concentration of the plant extract and the method of the test adopted. The active components of the plant have no antifungal effect on the tested yeast (Candida albicans). These findings are discussed in relation to plant chemicals as a means of disease control and also to the problem of microbial resistance to synthetic drugs.     

废橡胶颗粒浸提液物质释放及其浸种对草坪植物生长的影响

纯胶粒浸提液、胶粒与壤土混合的浸提液中重金属含量分析表明,纯胶粒浸提液中Zn含量最高,其次为Pb,而Cd与Cu最少;与纯胶粒浸提液相比,胶粒与壤土混合的浸提液中Zn含量显著降低.紫外吸收光谱图显示,胶粒粒径越小,浸提液中有机物越复杂.用4种不同粒径胶粒的浸提液对2种草坪植物种子浸种处理后进行培养,研究了草坪植物的生长效应.结果表明,胶粒浸提液浸种对2种草坪植物的种子萌发率影响不大,但对株高产生不同的影响.对黑麦草而言,以2～4 mm胶粒浸提液浸种的株高为最高,1～2和4～6 mm胶粒浸提液浸种株高与之差异较大,分别降低1.52和1.32 cm,但均与对照无显著差异.对于高羊茅,以粒径1～2 mm胶粒浸提液浸种的株高为最低,比对照降低了18.76%,其它处理间无明显差异.浸提液浸种对黑麦草地下生物量有明显的抑制作用,但对根长生长有促进作用.胶粒浸提液浸种对2种草坪植物的地上生物量无明显影响.从胶粒浸提液的物质释放及其浸种对草坪植物生长的影响来看,废胶粒可用于运动场草坪的基质组配.     

三种植物粉剂对四纹豆象(鞘翅目:豆象科)行为、死亡率和繁殖的影响

The effects of powders from dry flower buds of Eugenia aromatica Baill., seeds of Piper guineense Schum and Thonn and fruits of Capsicum frutescens L. on adult behaviour, mortality and reproductive fitness of the cowpea seed beetle, Callosobruchus maculatus （Fab.） were investigated under ambient laboratory conditions. All experiments were carried out in glass Petri plates. All powders elicited aversion in adult beetles. The contact toxicity symptoms included restlessness, loss of coordination, knock down and eventual death of adult beetles. These behaviours were more pronounced with E. aromatica in which adult beetles died within 16 hours. P. guineense and C. frutescens powders did not cause 100% mortality of adult beetles, even after 24 hours. Each of the three powders significantly （P 〈 0.05） reduced the mating competition of adult males after sub-lethal exposure for one, two, and three hours, respectively. E. aromatica powder caused more reduction in male mating competition for females than any of the other two powders after each period of exposure. Receptiveness of treated females to courting males was also decreased by exposure to any of the three powders. Similarly, E. aromatica powder caused greater decreases in female receptiveness to males than any of the other two powders after each period of exposure. Exposure of either adult male or female C. maculatus to the powders for sub-lethal times of three, six and nine hours significantly reduced the fecundity of the beetles. E. aromatica powder caused the most reduction of eggs laid and also significantly reduced fertility of the eggs.     

天然植物提取物对茄子黄萎病菌的抑制活性

以茄子黄萎菌为供试菌种,研究了54种天然植物的乙醇提取液对茄黄萎菌的抑菌活性. 结果表明, 有15种植物提取物对茄子黄萎菌菌丝生长抑制率大于50%,其中细辛、黄连、厚朴、儿茶、苦参、甘草、蛇床子、桔梗、洋葱的提取物对供试菌菌丝生长抑制作用较强,抑制效果均在65%以上,蛇床子的抑菌率达86.84%.有16种植物提取物对病菌孢子萌发的抑制作用大于70%,其中7种植物提取物对孢子萌发的抑制率大于95%以上,细辛、黄连、厚朴基本上抑制了孢子的萌发.儿茶提取物对菌丝生长的抑制效果较差,但却显著抑制了孢子萌发,抑制率达100%.蛇床子提取物虽然抑菌效果较高,但其处理的孢子萌发率为11.3%.研究发现天然植物提取物中存在着抑制黄萎菌的活性物质,这为生物防治黄萎病和进一步研究蔬菜抗病增产理论提供了新的思路与途径.     

Effect of some pulverised plant materials on the developmental stages of fish beetle,Dermestes maculatus Degeer in smoked catfish (Clarias gariepinus) during storage

The effectiveness of pulverised plant materials; Tithonium diversifolia, Afromomum melegueta, Nicotiana tabacum, Monodora myristica and Piper guineense as ovicidal, larvicidal and adult deterents of fish beetle (Dermestes maculatus) in smoked catfish (Clarias gariepinus) during storage were evaluated. Leaves of T. diversifolia, N. tabacum and seeds of A. melegueta, M. myristica and P. guineese were dried and pulverised into powder. Adults and larvae of third generation (F3) of D. maculatus were introduced into Kilner jars containing disinfested fish samples. Pulverised plant materials were applied to the surface of the fish samples at 10% (w/w) and monitored for 40 days, while egg hatchability of the insects was monitored for seven days. The result showed that all the plant materials had varying degree of insecticidal activities. Pulverised powder of P. guineense and A. melegueta were the most effective and significantly (P < 0.05) inhibited egg hatchability and adult emergence of D. maculatus in smoked catfish. N. tabacum gave the lowest insecticidal effect on adults, larvae and eggs of D. maculatus. However, the larvae of D. maculatus were not significantly (P > 0.05) affected by the plant materials. The percentage weight loss in fish treated with P. guineense and A. melegueta were minimal compared with the untreated fish sample. The result of this study showed that pulverised plant materials obtained from P. guineense and A. melegueta could be used to deter egg hatchability and adult emergence of D. maculatus in smoked catfish during storage. This could also reduce percentage losses due to insect infestation on smoked fish during storage.     

Inhibitory effect of botanical extracts against Alternaria alternata of aloe vera dry rot

Aloe vera dry rot caused by Alternaria alternata, is one of the most serious fungal diseases affecting the commercial cultivation of aloe vera in North India. Control of this disease through chemical is quite expensive and not ecofriendly. The plant extracts as biopesticdes act as a vital components for the management of this disease. Evaluation of some plant extracts was carried out against A. alternata in laboratory conditions. The extracts were prepared at 5% and 10% concentration and were evaluated through inhibition in radial growth (food poison technique) and spores (conidia) germination (hanging drop technique) against A. alternata. Neem leaf extract gave 58.6% inhibition in radial growth and 56.5% in spore germination at 10% concentration followed by Ocimum sanctum which was found effective and gave 54.7% inhibition in radial growth and 50.4% in spore germination over control.     

Differential belowground allelopathic effects of leaf and root of Mikania micrantha

This study evaluates the relative contributions of leaves and roots to the belowground allelopathic effects of Mikania micrantha. The hypothesis that leaves contribute more to the allelopathic effect than roots was experimentally tested. We assessed the allelopathic effects of aqueous extracts from Mikania leaves and roots on the seed germination and seedling growth of two co-occurring woody plants in southern China, Lagerstroemia indica L. and Robinia pseudoacacia L. The results showed that the aqueous extracts from Mikania leaves and roots had inhibitory effects on the woody species. Allelopathic activity depended on the concentration of the extracts, target species, and the extract sources (i.e., leaves vs. roots of Mikania). Leaf extract showed stronger allelopathic effects than root extract on germination percentage, initial germination time, speed of germination, and shoot height; while root extract had greater allelopathic effects on roots than leaf extract. The latter phenomenon might greatly promote the invasion success of Mikania due to more direct and effective allelopathy of root. Our results suggest that allelopathy of root extract on belowground biomass might be greater than that of leaf extract for some species in contrast allelopathy of leaf extract on belowground biomass might also be greater than that of root extract for other species, at least for their effects on root growth of the target species.