NEWCONE AND SEED PESTS COLLECTED IN NORTHEASTERN CHINA BARBARA FULGENS KUZNETSOV (LEPIDOPTERA:TORTRICIDAE) THE LUSTROUS SPRUCE CONE MOTH

Arecentsurveyofconeandseedinsectsoccuringinsomeconiferforests'ofHeilongiiangandInnerMongoliaprovinces.gaveustheopportunitytocol1ectseveralspeciespreviouslyunknownfromChina(Fangetal.,1988).ThispaperisthefirstofaseriesprovidinginfOrmationgathereduponthemorphologicalcharacteristics,biologicalcycleanddamagecorrespondingtothesespeciesinNortheasternChina.Thelustrousspruceconemoth,BarbarafulgensKuznetsov,wasprevious-lyrecordedfromthesingleFarEastSovietUnion(intheKhabarovskarea),yetclosetoHeilon…     

Screening techniques and sources of resistance to foliar diseases caused by major necrotrophic fungi in grain legumes

Summary Necrotrophic pathogens of the cool season food legumes (pea, lentil, chickpea, faba bean and lupin) cause wide spread disease and severe crop losses throughout the world. Environmental conditions play an important role in the development and spread of these diseases. Form of inoculum, inoculum concentration and physiological plant growth stage all affect the degree of infection and the amount of crop loss. Measures to control these diseases have relied on identification of resistant germplasm and development of resistant varieties through screening in the field and in controlled environments. Procedures for screening and scoring germplasm and breeding lines for resistance have lacked uniformity among the various programs worldwide. However, this review highlights the most consistent screening and scoring procedures that are simple to use and provide reliable results. Sources of resistance to the major necrotrophic fungi are summarized for each of the cool season food legumes. Marker-assisted selection is underway for Ascochyta blight of pea, lentil and chickpea, and Phomopsis blight of lupin. Other measures such as fungicidal control and cultural control are also reviewed. The emerging genomic information on the model legume, Medicago truncatula, which has various degrees of genetic synteny with the cool season food legumes, has promise for identification of closely linked markers for resistance genes and possibly for eventual map-based cloning of resistance genes. Durable resistance to the necrotrophic pathogens is a common goal of cool season food legume breeders.     

DNA sequence polymorphisms and their application to bread wheat quality

Single-nucleotide polymorphisms (SNPs) constitute an abundant source of DNA polymorphisms, which have been successfully used to identify loci that are associated with a particular phenotype. Additionally, such markers could be efficiently used in combination with doubled haploid technology to improve the efficiency of breeding programmes. Information on such markers in plants is still scarce. For bread wheat, SNP data are restricted to a few genes. This can be explained by the hexaploidy of Triticum aestivum which makes SNP discovery difficult. We developed a novel method for SNP discovery in bread wheat. The strategy is based on the development of highly specific PCR-primers, which were used to sequence 27 lines. SNPs were discovered from sequence alignment data. Some SNPs were identified by mass spectrometry in a collection of 113 lines, which were both evaluated for agronomic traits and genotyped at 42 neutral microsatellite loci. Traits investigated include: protein content, the quantity of high-molecular-weight glutenins and that of the GluBx subunit. The 42 markers were used to infer population structure, which was included in linear models for association studies. The results of this preliminary study showed 89 SNPs in approximately 20 kbp, i.e., one SNP every 223 bp on average. Six SNPs were genotyped: three were located along the sequence of Glu-B1-1, while three non-synonymous SNPs were located along the sequence of the B homoeologous gene coding for SPA (Storage Protein Activator). The SNPs from Glu-B1-1 had a significant effect on the studied variables, whereas those of SPA had no effect. Such results might indicate that some haplotypes for Glu-B1-1 are linked to higher protein content, through an increased amount of high-molecular-weight glutenins, especially the GluBx subunit.     

Comparison of two methods for evaluating waste of a flow through trout farm

European water legislation enforces increasingly restrictive measures with regards to reduction of water consumption and waste emission in order to minimise the potential environmental impact of the agro industry sector. Fish farms are particularly concerned, but legislation covering effluent discharge varies significantly from country to country. However, recommendations and directives from institutional, national or regional bodies suggest the enforcement of increasingly strict waste reduction measures and the development of waste treatment. Before treatment, it is necessary to evaluate waste production in terms of composition and quantity. The waste quantification methods used today for fish culture systems are either based on direct measurements of nutrient and suspended solid fluxes or on indirect evaluation based on the digestibility coefficients of the feed constituents. The objective of the present study is to evaluate the waste of a freshwater flow through farm using both approaches and to discuss their applicability, drawbacks and advantages from the viewpoints of fish farmers and control authorities. Waste production on the farm was monitored during several 24 hour cycles in order to characterise the effluents of the system. The predictions and measurements for the total nitrogen (TN) parameter were well correlated, but measured and predicted suspended solids (SS) and total phosphorus (TP) values presented a weaker correlation coefficient. The hydrobiological method gives details on the N and P forms of waste but this method is heavy and it is difficult to obtain representative samples and flow rate measurements. The nutritional method is the simplest to use, provided that feed data are available.     

Assessing the plant minimal exchangeable potassium of a soil

The plant minimal exchangeable K (E_Pl,min) defines the lower accessible limit of the most available pool of soil K to plants. It is also an index of long‐term K reserve in soils. However, its estimation by the classical method of exhaustion cropping is laborious. This study aimed at comparing E_Pl,min values obtained by the exhaustion cropping method with E_Pl,min values estimated by an alternative approach based on the cationic exchange capacity (CEC) of the infinitely high selective sites for K (i.e., always saturated with K) in the K‐Ca exchange (E_K‐Ca,min). A set of 45 soil samples, corresponding to the various fertilization K treatments of 15 long‐term K fertilization trials, was used in this study. The selected soil samples presented a wide range of texture, CEC, and exchangeable K. The plant minimal exchangeable K was found more or less independent of the K treatment, whereas E_K‐Ca,min increased when the soil exchangeable K content increased. The plant minimal exchangeable K was systematically lower than E_K‐Ca,min, showing that E_K‐Ca,min is at least partially available to the plant. Hence, E_K‐Ca,min is not a surrogate of E_Pl,min. Conversely, the plant minimal exchangeable K was strongly, positively correlated to soil CEC (measured at soil pH; r² = 0.90^***). This soil property can consequently be used as a proxy of E_Pl,min.     

A first insight into genotype × diet interactions in European sea bass (Dicentrarchus labrax L. 1756) in the context of plant‐based diet use

This preliminary study assessed genotype × diet interaction in late growth of European sea bass (Dicentrarchus labrax) fed with either a fish meal (FM)‐ or a fish oil (FO)‐based diet (M) or an all‐plant‐based (PB) diet. A total of 550 fish from 224 families were reared together and tagged. DNA was sampled and microsatellites were used to assign parentage. When fish weight was 192 ± 54 g, two tanks were fed with M (FM: 100%; FO: 100%) and two others with PB (FM: 0% and FO: 0%). Body weight (BW), fork length (FL) and fillet lipid content (CorrFat) were analysed with a linear model and with REML methodology. We observed no significant differences between groups, but a slightly lower (P=0.03) daily growth coefficient in sea bass fed PB than in those fed M. Heritability estimates of BW differed significantly from zero (PB: 0.37 ± 0.18; M: 0.47 ± 0.24). Sire × diet interactions were significant and genetic correlations ranged between 0.51 and 0.87, showing genotype × diet interaction for BW and CorrFat. For the first time, genetic parameters in the context of total replacement of marine fishery by‐products were estimated in European sea bass, showing re‐ranking of family performances with extremely contrasted diets.     

Dietary niche expansion and niche shift in native marble trout (Salmo marmoratus) living in sympatry with introduced rainbow trout (Oncorhynchus mykiss)

The non‐native rainbow trout (Oncorhynchus mykiss) has been introduced worldwide for angling purposes and has established self‐reproducing populations in many parts of the world. Introduced rainbow trout often have negative effects on the native salmonid species, ranging from decrease abundance, growth and survival, to their local extinction. Assessing the effects of introduced rainbow trout on the native species is thus crucial to better set up conservation programmes. In this study, we investigated the effects of non‐native rainbow trout on the diet of native marble trout (Salmo marmoratus) living in the Idrijca River (Slovenia). An impassable waterfall separates the stream in two sectors only a few hundred metres apart: a downstream sector (treatment) in which marble trout live in sympatry (MTs) with rainbow trout (RTs) and an upstream sector (control) in which marble trout live in allopatry (MTa). Specifically, we investigated using stable isotopes the effects of rainbow trout on dietary niche, diet composition, body condition, and lipid content of marble trout. We found dietary niche expansion and niche shift in marble trout living in sympatry with rainbow trout. Compared to MTa, MTs had higher piscivory rate and showed higher body condition and prereproduction lipid content. Our results indicate that the presence of rainbow trout did not have negative effects on marble trout diet and condition and that changes in dietary niche of marble trout are likely to be an adaptive response to the presence of rainbow trout, and further research is needed to better understand.     

Effects of silage preservation on astaxanthin forms and fatty acid profiles of processed shrimp (Pandalus borealis) waste

Acid silage of shellfish processing waste has been reported to be a good and economical technique to protect these biomasses from bacterial decomposition. Shrimp (Pandalus borealis) by-products contain some value-added nutrients for the aquaculture industry such as carotenoid pigments (mainly astaxanthin) and n − 3 polyunsaturated fatty acids. The aim of this work was to determine the effect of ensiling shrimp waste during a long period of time (more than 3 months) on some unstable components such as the astaxanthin forms (free, mono- and diesterified) and polyunsaturated fatty acids. Comparisons of astaxanthin forms and the fatty acid profiles were performed on defrosted shrimp waste and on a 14-week-old shrimp waste silage. No significant difference (P ≥ 0.05) in the total lipids extracted from the two forms of shrimp waste was observed. Nevertheless, a small quantity of the red pigment, presumably an astaxanthin portion, was observed to stay firmly bound to the shrimp carapace after the solvent extraction in shrimp waste compared to the full recovery obtained in ensiled shrimp waste. This may explain the significantly (P < 0.05) higher concentration of total astaxanthin (4.57 vs 3.99 mg/g) found in the crude oil extracted from shrimp waste silage. Higher percentages (P < 0.01) of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) were found in esterified astaxanthin from shrimp waste silage (43.9% and 45.5%) in comparison with their shrimp waste (24.7% and 20.3%) counterparts. This suggests that EPA and DHA are the principal fatty acids esterified with the portion of astaxanthin linked to chitin in the shrimp carapace. The utilization of shrimp waste silage as a pigmenting component of salmonid feeds is also discussed.     

反刍动物肝片吸虫病--免疫与疫苗策略

反刍动物肝片吸虫病在世界范围内对畜牧业造成严重的经济损失，需要研制疫苗进行防制。本文介绍动物肝片吸虫病的保护性免疫应答的表现形式，对保护性免疫应答效应机制和寄生虫免疫逃避机制展开讨论，阐述选择疫苗候选抗原的不同策略，最后探讨研制抗肝片吸虫疫苗所受到的限制因素。     

Natural cyclopeptides as leads for novel pesticides: tentoxin and destruxin

Difficulties in synthesis make natural cyclopeptides challenging targets for chemists. Our interest focused on two natural toxic cyclopeptide series produced by pathogenic fungi: tentoxin, [cyclo-(N-MeAla¹-Leu²-N-Meδ^zPhe³-Gly⁴)] and the destruxins [cyclo-(Pro¹-Ile²-N-MeVal³-N-MeAla⁴-β-Ala⁵-HA⁶)]. The total syntheses of these two bioactive series were optimised, and several analogues were designed and synthesised to establish structure–activity relationships. The importance of synthetic analogues in the identification of molecular targets and the explanation of mechanisms of action was demonstrated. Such systematic investigations can determine the crucial features responsible for the activity of the natural compound and help the design of more powerful or more selective products. © 1998 SCI.