Long-term follow-up of blood lead levels and haematological and biochemical parameters in heifers that survived an accidental lead poisoning episode

Four of 10 heifers that survived an episode of lead poisoning caused by an old broken battery in the pasture were periodically monitored from days 14 to 205 after the episode, with the aim of (i) determining the time-course of lead clearance from blood; and (ii) assessing whether the exposed cattle showed changes in haematological parameters or serum markers of hepatic and renal function (e.g. serum creatinine level) that might be useful as indicators of subclinical toxicity. On the first sampling day, lead levels in blood varied between 0.478 and 0.758 mg/l. The half-life of lead in blood was rather variable, ranging from 68 to 266 days. Despite the high blood lead levels, no significant changes were detected in haematological parameters or hepatic/renal markers, all of which remained within normal ranges. In conclusion, these cattle that survived an episode of lead poisoning may constitute a risk for human consumers, but do not appear to have suffered severe health consequences themselves.     

Use of SSR markers to assess sexual vs. apomictic origin and ploidy level of breeding progeny derived from crosses of apple proliferation-resistant Malus sieboldii and its hybrids with Malus × domestica cultivars

To obtain apple rootstocks resistant to apple proliferation and suitable to modern fruit growing, 24 cross-combinations were performed over a 5-year period using Malus sieboldii and its hybrids as donors of the resistance trait and standard apple rootstock Malus  ×  domestica genotypes as donors of agronomic value. Breeding with these genotypes was achieved despite different degrees of apomixis and polyploidy. Sets of five to six locus-specific microsatellite markers were identified for characterizing each progeny. Supported by flow cytometry these markers were applied to infer mode of reproduction, genomic constitution and ploidy level. Microsatellites allele composition identical to the maternal parent was revealed in 1668 of 3032 seedlings indicating seed formation through apomixis. Complete genetic recombination was found in 398 seedlings. The remaining hybrids displayed a higher ploidy than that of the parental plants which was consistent with the fertilization of unreduced egg cells. Thus, for each cross-combination, microsatellite loci were identified which enabled a reliable prediction of the ploidy level. They can now be applied in routine screening to distinguish sexual from apomictic progeny.     

Development and characterisation of a <Emphasis Type="Italic">Brassica carinata</Emphasis> inbred line incorporating genes for low glucosinolate content from <Emphasis Type="Italic">B. juncea</Emphasis>

The presence of high levels of sinigrin in the seeds represents a serious constraint for the commercial utilisation of Ethiopian mustard (Brassica carinata A. Braun) meal. The objective of this research was the introgression of genes for low glucosinolate content from B. juncea into B. carinata. BC₁F₁ seed from crosses between double zero B. juncea line Heera and B. carinata line N2-142 was produced. Simultaneous selection for B. carinata phenotype and low glucosinolate content was conducted from BC₁F₂ to BC₁F₄ plant generations. Forty-three BC₁F₄ derived lines were selected and subject to a detailed phenotypic and molecular evaluation to identify lines with low glucosinolate content and genetic proximity to B. carinata. Sixteen phenotypic traits and 80 SSR markers were used. Eight BC₁F₄ derived lines were very close to N2-142 both at the phenotypic and molecular level. Three of them, with average glucosinolate contents from 52 to 61 micromoles g⁻¹, compared to 35 micromoles g⁻¹ for Heera and 86 micromoles g⁻¹ for N2-142, were selected and evaluated in two additional environments, resulting in average glucosinolate contents from 43 to 56 micromoles g⁻¹, compared to 29 micromoles g⁻¹ for Heera and 84 micromoles g⁻¹ for N2-142. The best line (BCH-1773), with a glucosinolate profile made up of sinigrin (>95%) and a chromosome number of 2n = 34, was further evaluated in two environments (field and pots in open-air conditions). Average glucosinolate contents over the four environments included in this research were 42, 31 and 74 micromoles g⁻¹ for BCH-1773, Heera and N2-142, respectively. These are the lowest stable levels of glucosinolates reported so far in B. carinata.     

Experimental culture of larvae,post‐larvae and juveniles of the West Indian top shell,Cittarium pica (Linnaeus 1758)

The West Indian top shell, Cittarium pica, is an endangered vetigastropod of ecological and commercial value from the Caribbean. In order to assess the use of aquaculture as a tool for its sustainable production and conservation, embryos were produced in hatchery and experimentally cultured until juveniles under different conditions. Embryos were incubated under two temperatures (25 and 29°C) and six densities (0.3, 0.6, 1.0, 4.0, 9.0 and 37.0% of bottom‐coverage). Larvae were reared under different temperatures (25 and 27°C), densities (0.5, 1, 1.5 and 10 larvae/ml) and culture systems (static and down‐welling). Post‐larvae were obtained in three different settling conditions, and the early juveniles were cultured supplying fresh seaweed (Laurencia obtusa and Padina gymnospora), natural multi‐specific biofilm and Cylindroteca sp. biofilm. The growth and survival of embryos and larvae were not affected by temperature, but they were affected by density. Higher values were obtained at low densities (<1% of embryos bottom‐coverage and <1 larvae/ml), except for the growth of larvae, which was similar among treatments. Higher larval survival was recorded using the static culture system, and higher percent of post‐larvae recovered was associated with lower density of crawling veliger (0.2 and 0.1/ml), while its higher growth rate was related to the use of biofilms with conspecific mucus and low water‐flow (50%/h). The type of food tested did not affect the juvenile growth, but higher survival was obtained in those fed with seaweed than with multi‐specific biofilm.     

Light quality and intensity of light-emitting diodes during pre-cultivation of Picea abies (L.) Karst. and Pinus sylvestris L. seedlings – impact on growth performance,seedling quality and energy consumption

Three different LED lamps with continuous spectra were compared against commonly used fluorescent lights. The lamps were characterized by light output, energy consumption and spectral quality for plant growth. The biological effects of light quality were compared by pre-cultivating seedlings of Picea abies (L.) Karst. and Pinus sylvestris L. under each spectrum for 35 days in a growth chamber with controlled temperature, humidity and photoperiod. The seedlings were then transplanted and cultivated for one vegetation period at the nursery, then planted outdoors on a forest field trial and followed for three years. The seedlings showed similar growth performance for all spectra tested. LED lamps have several advantages to fluorescent light such as energy consumption, longer life span and adjustable light intensity. Regarding light intensity the effects on growth performance were studied for both species using the most promising LED spectra. The photosynthetically active radiation (PAR) was maintained at 50, 100, 200 and 400 μmol?m^?2?s^?1. Unlike energy consumption, seedling development did not display a linear relationship to light intensity. Instead, the results show an optimum light level between 100 and 200?μmol?m^?2?s^?1 for the shade tolerant Picea abies seedlings and a level of around 200?μmol?m^?2?s^?1 for the more shade intolerant Pinus sylvestris seedlings.     

Occurrence and incidence of viruses infecting green beans in south-eastern Spain

A study was conducted to determine the identity and prevalence of viruses in 455 greenhouses in the main Spanish green bean growing area. Directed surveys were conducted in 422 crops from 2000–2004 to collect samples from diseased plants displaying symptoms that could be attributed to viruses. The samples were analysed to detect any virus by means of dsRNA extraction, mechanical inoculation to test plants, as well as ELISA and/or RT-PCR tests to detect potyviruses, geminiviruses and viruses previously known to infect beans in Spain. Random surveys were conducted in the years 2002 and 2005 (in 21 and 12 greenhouses, respectively) to study the actual incidence of known viruses in the area. Symptoms were recorded in 23,108 plants from which 664 plants were collected and analysed by ELISA or RT-PCR. The results of the directed surveys showed that all the analyzed crops carried the cryptic virus Phaseolus vulgaris endornavirus (PVuV), whereas phytopathogenic viruses appeared in smaller percentages of the crops: Tomato yellow leaf curl virus (TYLCV) 20.4%, Southern bean mosaic virus (SBMV) 9.0%, Tomato spotted wilt virus (TSWV) 4.0%, and the new species Bean yellow disorder virus (BnYDV) that broke out in 2004 with occurrence values higher than 34.3% that year. From 2000–2004 an important decrease in TYLCV was observed, along with a slight increase in SBMV and a consistently low occurrence of TSWV. The results of the random surveys confirmed the increased occurrence of virus detected during the directed surveys, and furthermore demonstrated the percentage of incidence for each virus.     

Inheritance of very high linoleic acid content and its relationship with nuclear male sterility in safflower

Safflower (Carthamus tinctorius L.) possesses the highest amount of linoleic acid among the 10 major vegetable oil crops of the world. Very high linoleic acid content is controlled by recessive alleles at a single locus Li. However, deviated segregations from the expected monogenic inheritance have been observed in crosses involving nuclear male‐sterile (NMS) lines. The present research was undertaken to study the inheritance of very high linoleic acid content in safflower and its relationship with nuclear male sterility. F₁, F₂, F₃, BC₁F₁ and BC₁F₂ seed generations were evaluated in a cross between CR‐142 (a line with very high linoleic acid content, 88%) and CL1 (an NMS line with wild‐type linoleic acid content, 74%). The genetics of linoleic acid content in male‐sterile plants was determined by testcrossing with CR‐142. The results confirmed monogenic inheritance. The analysis of the F₃ and BC₁F₂ to CL1 seed generations demonstrated a repulsion‐phase linkage between Li and Ms loci, the latter conferring the NMS trait. The recombination rate between Li and Ms was estimated to be 0.09.     

Nondestructive assessment of protein content in single seeds of rapeseed (Brassica napus L.) by near-infrared reflectance spectroscopy

The potential of near-infrared reflectance spectroscopy (NIRS) to detectwithin-plant differences for seed protein content was investigated. Fourhundred and fifty-one single seeds were scanned by NIRS using a specialadapter. After non-destructive NIRS scanning, the seeds were analysed forprotein content by the Dumas combustion method and a calibrationequation was developed. A validation set of 117 additional seeds fromthree individual plants from the cultivars Bristol, Lirajet and Maplus wasanalysed for protein content both by NIRS and combustion. The coefficientof determination between NIRS and combustion values in the validation setwas 0.94, with a standard error of performance (SEP) of 0.77% and aratio of the SEP to the standard deviation (SD) of the validation set of0.28. The coefficient of variation (CV) for seed protein content inindividual plants, as determined by the combustion method, was 11.7%for Bristol, 8.9% for Lirajet, and 9.5% for Maplus. The comparison ofsuch variation with the standard error (SE) of NIRS analysis, defined as thecombination of the SE of the combustion method and the SEP of NIRScalibration equation, revealed that the maximum explainable variance withinindividual plants that can be detected using NIRS analysis of proteincontent in single seeds was 0.86 for Bristol, 0.83 for Lirajet, and 0.85 forMaplus. These results demonstrated that NIRS is a powerful tool fornon-destructive assessment of within-plant variation for seed protein contentin rapeseed.     

Structure of RNA in ribosomes

The 50S and 30S ribosomes and 23S and 16S RNA were hydrolyzed with ribonuclease A. The rate constants and number of fragments produced were determined for each reaction. The conformation of 23S RNA changes when the RNA is extracted from the ribosome. Specific regions of the RNA in 50S and 30S ribosomes are protected from hydrolysis by the ribosomal proteins.