Polymorphisms in cyanogenic glucoside and cyano‐amino acid content in natural accessions of common vetch (Vicia sativa L.) and selection for improved agronomic performance

Common vetch (Vicia sativa L.) is an important annual forage legume. It is used as a cover crop, green manure, pasture legume and for silage and hay production. Its seeds can be used as a source of highly digestible protein and minerals in animal diets. However, their utilization as a feedstuff for monogastric animals is hindered by the fact that the seeds contain cyanogenic antinutritional factors that reduce their palatability. An effective utilization of V. sativa seeds as a successful monogastric feed stuff requires selection for higher protein availability and minimization of the cyanogenic antinutritional factors content. In this study, we selected one natural accession named Mjez Ibeb, from a collection of 25 accessions and cultivars, based on its superior agronomic performance and its naturally occurring genetic variation for cyanogenic traits. We investigated the genetic variation that exists for the cyanogenesis trait in more detail and analysed the seeds of 133 lines derived from accession Mjez lbeb. Of these, 40 naturally polymorphic lines that showed deficiencies in cyanogenesis and cyano‐amino acid content, were subsequently selected for detailed chemical analysis. Cyanogenic glucosides and cyano‐amino acid concentrations varied widely in the 40 lines. Multivariate analysis was performed and three lines (L₁₆, L₂₁, L₁₈) with low content of cyanogenic compounds were identified.     

Toward a methodology for the implementation of energy saving technologies

ERDA (The Energy Research and Development Administration) was given the mandate to perform or cause to be performed the research and development of alternative energy sources and energy conserving technologies and strategies. However, answers to the energy dilemma not only depend upon the proof that a technology or strategies exist but that they reach the end user and actually conserve energy. At the same time there is an indication that R & D projects carried out by or supported by the Federal Government are seldom utilized. This lack of utilization can be partially blamed on a lack of concern and knowledge surrounding the implementation process. To avoid this pitfall in the case of energy research, the study outlined here is a beginning to understanding the implementation process and, specifically, the implementation of energy saving technologies.

     

Determination of Pea Proteinase Inhibitors Using ELISA Based on Monoclonal Antibodies

Abstract

An immunoassay method for analysis of trypsin and chymotrypsin inhibitor activity in seeds from different pea cultivars has been developed. This method is fast, cheap and well suited for screening of large numbers of seed samples. The technique is based on enzyme linked immunoassay (ELISA) using monoclonal antibodies produced against pea (Pisum sativum L.) proteintype trypsin inhibitors (PPI). The results obtained by ELISA have been compared with results achieved by using traditional enzymatic analyses for determination of both trypsin and chymotrypsin inhibitor contents, and these methods showed good agreement. Great differences in PPI levels have been found between various pea cultivars grown in Finland and Denmark, and these differences comprised both the total amount of PPI and the relative composition of individual PPI. Several proteins occurring in pea exhibited inhibitor activity, and at least 10 PPI inhibitors with p/ values 4.9–7.8 were detected. Pea cultivars with low PPI levels had a PPI composition different from the PPI composition found in cultivars with high PPI levels.     

Activity patterns of Gulf Sturgeon (Acipenser oxyrinchus desotoi) in the staging area of the Pascagoula River during fall outmigration

Environmental cues that are associated with individual movement of threatened Gulf Sturgeon from upriver areas to nearshore and offshore winter feeding areas have been described throughout much of their range in the Gulf of Mexico. In this study, we focus on small‐scale movement of Gulf Sturgeon between summer ‘holding’ areas and the fall staging area in the Pascagoula River system (Mississippi, USA). We evaluated a set of logistic regression models using Akaike's Information Criterion and found that relative changes in barometric pressure, time of day, and water temperature were cues for small‐scale Gulf Sturgeon movements during fall outmigration. Numerous environmental cues appear to drive the activity of Gulf Sturgeon in staging areas, indicating the complexity of abiotic factors affecting the observed staging patterns during emigration. The identification of the environmental drivers that are associated with Gulf Sturgeon movement is particularly important if these known saline transition zones change spatially annually with variable rainfall or due to water withdrawals and are used by Gulf Sturgeon making osmotic adjustments while moving downriver.     

Acquired canaliculocele with intranasal extension in a dog

To describe a case of a nasolacrimal canaliculocele with intranasal extension in a dog. A 6‐year‐old neutered female Jack Russell Terrier was referred to the Centre Hospitalier Vétérinaire des Cordeliers for a slowly enlarging mass adjacent to the medial canthus of the right eye of 5 months duration. Ophthalmic exam, ultrasound, fine needle aspiration, dacryocystorhinography and computerized tomography examinations were performed. Rhinoendoscopic treatment with marsupialisation of the endonasal canaliculocele was performed. Physical examination revealed a 3 cm diameter, subcutaneous mass beneath the medial canthus of the right eye, with a defect in the maxillary bone below. Dacryocystorhinography demonstrated blockage at the level of the nasolacrimal duct. Fine needle aspiration confirmed the cavitary nature of the lesion. During rhinoendoscopy, a mass containing watery fluid was found. Following marsupialisation with a large mass wall resection, the lacrimal drainage system irrigated freely in the nasal chamber. The communication of the lumen of the diverticulum with the lumen of the superior but not the inferior canaliculus was clearly demonstrated during endoscopy. Given negative immunohistochemical staining for smooth muscle actin and desmin, nasolacrimal dacryocele appears to be the most likely diagnosis. Histological examination confirmed that no goblet cells were present in the wall of the diverticulum, which is consistent with the canaliculus rather than the lacrimal sac. Complete resolution was observed without recurrence one year after surgery. Despite its rarity, a canaliculocele should be considered in adult dogs with nasolacrimal duct obstruction. Marsupialisation seems to be the appropriate therapy.     

Effects of azadirachtin injection in litchi trees (Litchi chinensis Sonn.) on the litchi stink bug (Tessaratoma papillosa Drury) in northern Thailand

The litchi stink bug (Tessaratoma papillosa Drury) is one of the major pests of litchi (Litchi chinensis Sonn.) in tropical Asia. Systemic effects of azadirachtin (at a concentration of 0.17 g active ingredient per centimeter trunk diameter) on T. papillosa were examined by injecting the dissolved product (NeemAzal U) into the trunks of four caged litchi trees in an orchard in northern Thailand. Four untreated caged trees served as control. Mean weekly mortality rates of individuals released on the treatment date (initially 55 nymphs per cage) were significantly higher in the treatment cages (55%) than in the control cages (10%) between the second and the fourth week of the experiment. Mortality in the treatment cages was probably due to both toxic effects (ecdysis inhibition) and antifeedant effects (starvation). Weekly mortality rates of individuals released 2 weeks after tree injection (initially 20 nymphs per cage) were not significantly different between treatment and control cages, indicating a weakening effect of azadirachtin, 2–3 weeks after tree injection. Azadirachtin concentration in ripe fruits was less than 5 mg/kg fruit pulp 18 days after tree injection. Although the results of this study are not yet sufficient for practical recommendations, they provide indications of alternative options for integrated pest management approaches. The azadirachtin tree injection method should also be tested against other pests of litchi, and of fruit trees in general.     

Effects of nitrogen source and defoliation on growth and biological dinitrogen fixation of Gliricidia sepium seedlings

Effects of four N sources and two defoliation treatments on growth and nitrogenase activity of Gliricidia sepium (Jacq.) Walp seedlings were studied in a greenhouse. All nutrients were supplied in irrigation water to the sterile growing medium. The N sources were: (1) 100 mg l(-1) of N supplied as NO(3) (-) (high-NO(3) (-)), (2) 50 mg l(-1) of N supplied as NO(3) (-) and inoculation with Rhizobium spp. medium-NO(3) (-)), (3)100 mg l(-1) of N supplied as NH(4)NO(3), and (4) inoculation with Rhizobium spp without mineral N (N(2)). At 35 weeks after sowing, mean total biomass was 130.5, 50.5, 22.9 and 17.4 g seedling(-1) in the NH(4)NO(3), N(2), medium-NO(3) (-) and high-NO(3) (-) treatments, respectively. The root/shoot ratio was high in all of the N treatments (1.73-2.77) because the seedlings had big taproots. The medium-NO(3) (-) treatment completely inhibited nodulation, whereas seedlings in the N(2) treatment were profusely nodulated. At 32 weeks after sowing, groups of seedlings in the N(2) and high-NO(3) (-) treatments were subjected to 50 or 100% defoliation. Closed-chamber acetylene reduction assays of intact root systems were conducted to compare nitrogenase activity at 7, 14 and 28 days after defoliation (DAD). At 7 and 14 DAD, nitrogenase activity of completely and partially defoliated seedlings was about 10 and 60%, respectively, of that of undefoliated controls. At 28 DAD, nitrogenase activity of completely defoliated seedlings was twice the predefoliation value, whereas nitrogenase activity of partially defoliated seedlings was only 87% of the predefoliation value. Recovery of nitrogenase activity was strongly correlated with foliage regrowth in the completely defoliated seedlings, but not in the partially defoliated seedlings. Abundant belowground C and N reserves in the large taproot probably contributed to the rapid recovery from defoliation. Accumulation of belowground biomass may also improve defoliation tolerance of mature trees.     

Agronomic performance of three cocoyam (<Emphasis Type="Italic">Xanthosoma violaceum</Emphasis> Schott) genotypes grown in Nicaragua

Cocoyam (Xanthosoma spp.), the third most important starch food crop in Nicaragua, can be cultivated countrywide. However, very little information about the field performance and genetic background of the different genotypes is available. In this study, the agronomic performance of three purple genotypes established in four locations with different climatic conditions, were evaluated during 2 years. Phenotypic characteristics, yield, and virus incidence were assessed and the time at which the different genotypes reached their physiological maturity was estimated. The trials were based on randomized complete block design with three or four blocks. Genotype × location interaction was found both for phenotypic and yield traits. A differential response of the genotypes to the varying climatic conditions at the locations is suggested to be one of the causes to the interaction. The unpredictable and variable climate in the area where cocoyam traditionally has been grown is one possible explanation to the frequent genotype × year interaction at that location. Other locations with more stable climate only showed an interaction between genotype and year in a few traits. The genotypic differences regarding the time when the area of the largest leaf reached its maximum and the variation in presence of sprouts and roots on the cormels at harvest, indicate differences in optimal harvest time between genotypes. The percentage of plants infected with dasheen mosaic virus (DMV) differed across locations but not between genotypes.     

Transgenic sugar beet tolerant to glyphosate

Phenology (i.e. the influence of environment on ontogeny) is the most important single factor influencing crop adaptation. The timing of flowering is particularly important since it largely determines when annual cereal, pulse and oilseed crops will subsequently be ripe for harvest. Two environmental factors are of overriding importance in the induction of flowering – photoperiod (daylength) and temperature. In seeking to predict times from sowing to flowering, f, it has proved profitable to analyse photothermal responses in terms of the rate of progress from sowing to flowering, 1/f. This paper summarises the advantages of a model based on rates rather than the traditional approach based on f. Over a wide range of photothermal regimes, the model involves just six coefficients, all of which (and their derivatives) have clearly defined biological meaning. Of paramount importance too is that the coefficients are not affected by the environment; they are genetic characters which determine phenotypic responses to the environment in a quantitative and predictable way.