Biochemical diversity in the genus Coffea L.: chlorogenic acids,caffeine and mozambioside contents

Summary The extent and nature of biochemical diversity in green coffee beans was established by a large sampling of genus Coffea, representing nine species from the Guineo-Congolian region, nine species from east Africa and seven species from Madagascar. HPLC analyses were used to determine the contents of caffeine, chlorogenic acids and mozambioside. Data processed by principal component analyses showed the existence of two metabolic pathways. One leads to the synthesis of small quantities of chlorogenic acids (< 2.5% dmb) and caffeine ( < 0.3 % dmb) while the other leads to large concentrations of chlorogenic acids (> 4.5% dmb) and caffeine (> 0.4% dmb). Their distribution in the genus Coffea is discussed in relation to the biogeographic origin of the plant material.     

Genetic diversity among watermelon (Citrullus lanatus and Citrullus colocynthis) accessions

Genetic diversity was estimated among 42 U.S. PlantIntroduction (PI) accessions of the genusCitrullus (of these, 34 PIs are reported tohave disease resistance), and 5 watermelon cultivars, using 30RAPD primers. These primers produced 662 RAPD markers that could berated with high confidence. Based on these markers, geneticsimilarity coefficients were calculated and a dendrogram wasconstructed using the unweighted pair-group method witharithmetic average (UPGMA). The analysis delineated threemajor clusters. The first cluster consisted of a group of fivewatermelon cultivars, a group of C.lanatus var. lanatusaccessions, and a group of C.lanatus var. lanatusaccessions that contained some C.lanatus var. citroidesgenes. The second cluster consisted of the C.lanatus var. citroidesaccessions, while the third cluster consisted of theC. colocynthis accessions.The two C. lanatus clustersdifferentiated from each other and from the C.colocynthis cluster at the level of 58.8%and 38.9% genetic similarity, respectively. Assessment ofgenetic diversity among accessions that have been reported to havedisease resistance indicated that resistance to either anthracnose,downy mildew, powdery mildew, or watermelon mosaic virus is foundamong all major groups of Citrullus PIs.Additionally, resistance to gummy stem blight or Fusarium wilt mayexist among C. lanatus var.citroides PIs. This study demonstrates thatmolecular markers can be useful in assessing genetic diversity, andin sorting Citrullus PIs into phylogeneticgroups prior to their evaluation for disease or pestresistance.     

The Relationship Between Yield and Fructan Exo-Hydrolases Activity in Two Drought Resistant Wheat Cultivars Grown Under Different Fertilizer and Tillage Treatments

Using two drought resistant wheat (Triticum aestivum L.) cultivars, ‘Changwu134’ and ‘Changhan58,’ a field experiment was conducted in ChangWu Agro-ecological Experiment Station on China's Loess Plateau during 2008 and 2009 to compare the effects of different fertilizer and tillage treatments on the fructan contents as well as fructan exo-hydrolase (FEH) activity in relation to wheat yield. We found that ‘Changhan58’ had greater yield and fructan content in the penultimate internode and higher FEH activity than did ‘Changwu134.’ For ‘Changhan58.’ applying 195 kg·ha^?1(120 +75) N plus 45000 kg·ha^?1 of pig manure and 120 kg·ha^?1 phosphate under conservation tillage produced the highest yield (6769 ka/ha), fructan content in penultimate internode, water use efficiency (WUE), as well as FEH activity among the fertilizer and tillage treatments. Therefore, routine soil management for wheat should focus on combined use of manures and inorganic fertilizer to enhance the amount and transportation efficiency of WSC and ultimately ensure greater yield.     

Dissolved nutrient release from solid wastes of southern bluefin tuna (Thunnus maccoyii, Castelnau) aquaculture

Finfish pens are point sources of dissolved nutrients released from fish metabolism or degradation of solid wastes. Nutrients leaching from uneaten feed and faeces are not usually quantified in mass budgets for these systems, leading to an overestimation of fish retention or deposition to the seabed. In this study, we investigated nutrient leaching from pellets and baitfish feed as well as faeces of southern bluefin tuna (Thunnus maccoyii) into seawater. Faeces were nitrogen depleted (51–54 mg N g⁻¹ dw) and phosphorus enriched (62–72 mg P g⁻¹ dw) compared with feeds (83–111 mg N g⁻¹ dw and 17–21 mg P g⁻¹ dw). Less phosphorus was available for leaching from pellets and faeces of pellet‐fed tuna (5–6%) than from baitfish and faeces of baitfish‐fed tuna (17–21%). The proportion of soluble nitrogen in pellets (15%) was also lower than in baitfish and faeces (35–43%). Leaching loads for a feed conversion ratio of 5 were estimated as 22 and 26 kg N tonne⁻¹ growth when baitfish or pellets were used as feed respectively. Phosphorus loads were estimated as 15 and 4 kg P tonne⁻¹ growth respectively. More than 90% of nitrogen loads, and approximately 50% of phosphorus, are likely to be released into seawater before solid wastes reach the seafloor.     

Evaluation of PCR,IEF and ELISA techniques for the detection and identification of potato cyst nematodes from field soil samples in England and Wales

Effective management of potato cyst nematodes (PCNs) requires simple, rapid and accurate identification and quantification of field populations. Soil samples from a survey of 484 fields in potato rotations in England and Wales were used to compare the identification and quantification of PCNs using IEF, PCR, ELISA and bait plant tests. The cyst counts and bait plant test revealed that 64.3% of field samples contained PCNs. Bait plant tests increased the detection rate of PCNs in field samples by 4–6.4%. This means that some infestations are cryptic and would not normally be detected by standard counts. IEF, PCR and ELISA methods distinguished between Globodera rostochiensis and G pallida and were able to register mixed populations; however they were not in full agreement. All methods suggested that G pallida is the dominant species in the field samples tested. The PCR results indicated that 66% of field samples contained pure G pallida, 8% contained pure G rostochiensis and 26% contained mixtures of the two species. Estimates of the relative process times taken per sample in the PCR, IEF and ELISA techniques are given. © 2001 Society of Chemical Industry     

Transmutation and functional representation of heterogeneous landscapes

Models of local small-scale ecological processes can be used to describe related processes at larger spatial scales if the influences of increased scale and heterogeneity are carefully considered. In this paper we consider the changes in the functional representation of an ecological process that can occur as one moves from a local small-scale model to a model of the aggregate expression of that process for a larger spatial extent. We call these changes spatial transmutation. We specifically examine landscape heterogeneity as a cause of transmutation. Spatial transmutation as a consequence of landscape heterogeneity is a source of error in the prediction of aggregate landscape behavior from smaller scale models. However, we also demonstrate a procedure for taking advantage of spatial transmutation to develop appropriately scaled landscape functions. First a mathematical function describing the process of interest as a local function of local variables is defined. The spatial heterogeneity of the local variables is described by their statistical distribution in the landscape. The aggregate landscape expression of the local process is then predicted by calculating the expected value of the local function, explicitly integrating landscape heterogeneity. Monte Carlo simulation is used to repeat the local-to-landscape extrapolation for a variety of landscape patterns. Finally, the extrapolated landscape results are regressed on landscape variables to define response functions that explain a useful fraction of the total variation in landscape behavior. The response functions are hypotheses about the functional representation of the local process at the larger spatial scale.     

Effectiveness of vaccines and vaccination programs for the control of foot-and-mouth disease in Uganda, 2001–2010

Foot-and-mouth disease (FMD) is a highly contagious disease of cloven-hoofed animals. In Uganda, FMD outbreaks are mainly controlled by ring vaccination and restriction of animal movements. Vaccination stimulates immunity and prevents animals from developing clinical signs which include lameness, inappetence, and decreased production. Ring vaccination and restriction of animal movements have, however, not successfully controlled FMD in Uganda and outbreaks reoccur annually. The objective of this study was to review the use of FMD virus (FMDV) vaccines and assess the effectiveness of vaccination programs for controlling FMD in Uganda (2001–2010), using retrospective data. FMD vaccine distribution patterns in Uganda (2001–2010) matched occurrence of outbreaks with districts reporting the highest number of outbreaks also receiving the largest quantity of vaccines. This was possibly due to “fire brigade” response of vaccinating animals after outbreaks have been reported. On average, only 10.3 % of cattle within districts that reported outbreaks during the study period were vaccinated. The average minimum time between onset of outbreaks and vaccination was 7.5 weeks, while the annual cost of FMDV vaccines used ranged from US $58,000 to 1,088,820. Between 2001 and 2010, serotyping of FMD virus was done in only 9/121 FMD outbreaks, and there is no evidence that vaccine matching or vaccine potency tests have been done in Uganda. The probability of FMDV vaccine and outbreak mismatch, the delayed response to outbreaks through vaccination, and the high costs associated with importation of FMDV vaccines could be reduced if virus serotyping and subtyping as well as vaccine matching were regularly done, and the results were considered for vaccine manufacture.     

Toxicity of chlordimeform and amitraz to the egyptian cotton leafworm (Spodoptera littoralis) and the tobacco budworm (Heliothis virescens)

The relative toxicity (μg a.i. g^?1 body wt) of the formamidine insecticide chlordimeform (CDM) and the triazapentadiene insecticide amitraz was examined in two species of noctuid moth Spodoptera littoralis and Heliothis virescens. When applied topically, there was an unexpected and marked difference in the toxicity of CDM base and its hydrochloride to adults of both species, the salt being appreciably more toxic. For H. virescens at least, this difference in toxicity could not be explained by differences in penetration. This trend was reversed for larval instars of S. littoralis; while there was relatively little difference in the toxicity of the base to adult and larval stages, the salt was at least 1000-fold more toxic to adults than to larvae. N¹-Demethylchlordimeform (DCDM) was the only metabolite of CDM to show biological activity against either species, but was much less toxic than the parent compound. Amitraz was far less toxic than either CDM or DCDM; like the CDM salt, it appeared to be more toxic to adult than larval stages of S. littoralis. Application of piperonyl butoxide significantly increased the toxicity of the CDM salt, DCDM and amitraz to adult H. virescens, the synergist being particularly effective with DCDM and amitraz. In contrast, piperonyl butoxide had no significant effect on the toxicity of DCDM, and slightly antagonised the toxicity of DCDM to fourth-instar larvae of S. littoralis.