Reflected‐light Influences the Coloration of the Peppermint Shrimp,Lysmata boggessi (Decapoda: Caridea)

One alternative to contribute to the reduction of the pressure on coral reef ecosystems brought about by an increasing demand for marine aquarium ornamentals is to improve and further develop the culture of desirable species for trade. Peppermint shrimp from the genus Lysmata are among the most intensively traded decapod in the trade and while several studies have been conducted to improve its culture, individuals obtained from culture facilities are generally paler than those collected from the wild. Because color is a fundamental component of the price tag on most marine ornamental live species, poorly colored animals command a lower price, reducing competitiveness. In this study, we evaluate the influence of tank background color (reflected light) on the morphological coloration change of Lysmata boggessi. In a 15‐d experiment, 30 individuals were exposed either to reflected‐red or white light and the relative change of coloration between initial and final moments was quantified with photography (RGB color model). At the end of the experimental period, shrimp exposed to red‐reflected light presented a more intense red coloration than those exposed to white‐reflected light. These results demonstrate that a simple change in background tank color can enhance shrimp external coloration. Such a cheap‐to‐implement procedure can support the culture of more colorful, hence more valuable ornamental shrimp that can compete with those captured from the wild.     

Effect of mycorrhizal inoculation and soil restoration on the growth of Pinus halepensis seedlings in a semiarid soil

An experiment was carried out to evaluate the growth of mycorrhizal Pinus halepensis seedlings planted in a semiarid soil amended with urban refuse in southeast Spain. Three fungal species were used: Pisolithus tinctorius, Rhizopogon roseolus, and Suillus collinitus. After 8 months, inoculated seedlings grown under controlled conditions did not differ significantly from controls with regard to plant height and nutrient assimilation. Other features such as root development and stem dry weight showed that the plants grew better in the absence of mycorrhizal inoculation. The mycorrhizal seedlings and the controls were planted in three experimental plots treated with urban refuse (0, 6, and 12 Kg m^-2). After 1 year of growth under field conditions the results showed that the type of fungus inoculated significantly influenced P. halepensis development. This effect varied with the dose of urban refuse. Plant growth was encouraged by the application of refuse but only at the lowest dose. Under these conditions P. tinctorius was the most effective fungus and R. roseolus yielded poorer plant development. The highest application of urban refuse led to notably worse results and a significant decrease in seedling growth compared to controls. In the control plot (without refuse) S. collinitus was the most effective fungus in plant growth improvement. The smallest application of urban refuse had a positive effect on the assimilation of N, P, and K in seedlings inoculated with P. tinctorius and S. collinitus.     

Towards an objective evaluation of persistency of <Emphasis Type="Italic">Lolium perenne</Emphasis> swards using UAV imagery

Perennial ryegrass (Lolium perenne) is a perennial crop used in temperate regions as forage. In L. perenne breeding programs, persistency is an important trait. Poor persistency results in sward degradation and associated yield and nutritive value losses. Breeders assess persistency of accessions using visual scoring in field plots during the 2nd or 3rd growing season. This evaluation system is easy and cheap but is not free from human bias. In this study, the correlation between the scoring done by different breeders was only 0.243. As an alternative we have developed a methodology to assess persistency of L. perenne breeding materials based on vegetation indices (VIs) derived from Unmanned Aerial Vehicle (UAV) imagery. The VIs Excess green (ExG2), Green Leaf Index and Normalized green intensity (GCC) were found to provide consistent results for flights carried out under different light conditions and were validated by ground reference information. The correlation between the VIs and the percentage of ground cover extracted from on-ground imagery was 0.885. To test the implementation of the method we compared the ExG2 value based approach to selection with a visual score based selection methodology as applied by two breeders. The breeding decisions of Breeder A agreed well with decisions based on ExG2 values (74.6%), but those of Breeder B displayed a lower agreement (54.0%). In contrast, agreement between decisions based on different flights was very high (91.6%). The methodology was validated for general applicability. In summary, the results demonstrate that basing persistency selection in L. perenne breeding programs on ExG2 values from UAV imagery is likely to be more objective in comparison to the currently-used visual scoring method.     

Effects of elevated CO2, water stress, and inoculation with Glomus intraradices or Pseudomonas mendocina on lettuce dry matter and rhizosphere microbial and functional diversity under growth chamber conditions

Purpose  

In this study, we investigated the effects of elevated atmospheric CO₂, drought, and inoculation with a plant-growth-promoting rhizobacterium (PGPR) or an arbuscular mycorrhizal (AM) fungus on microbial community composition and functional diversity in the rhizosphere of Lactuca sativa L. cv. Tafalla.     

Antioxidant activities and metal acquisition in mycorrhizal plants growing in a heavy-metal multicontaminated soil amended with treated lignocellulosic agrowaste

The plant growth, nutrient acquisition, metal translocation and antioxidant activities [ascorbate peroxidase (APX), glutatione reductase (GR), superoxide dismutase (SOD) and catalase (CAT)] were measured in plants growing in a heavy-metal (HM) multicontaminated soil inoculated with selected autochthonous microorganisms [arbuscular mycorrhizal (AM) fungus and/or plant growth promoting bacteria (PGPB)] and/or amended with an Aspergillus niger-treated agrowaste. The treated agrowaste on its own increased root growth by 296% and shoot growth by 504% compared with non-treated control plants. Both chemical and biological treatments, particularly when combined, enhanced plant shoot and root development. The stimulation effect on plant biomass was concomitant with increased AM colonization, P and K assimilation, and reduced metal translocation from soil to plant shoot. The treated residue, particularly through interactions with AM inoculation, produced the expected bioremediation effect, leading to enhanced plant development and successful rehabilitation of contaminated soil. The enhancement of CAT, APX and GR activities caused by AM inoculation suggests that AM colonization helped plants to limit oxidative damage to biomolecules in response to metal stress. The response of the plant's antioxidant activities to the amendment appears to be related to enhanced plant biomass production. The application of amendments and/or microbial inoculations to enhance plant growth and reduce metal translocation in multicontaminated soil could be a promising strategy for remediating HM pollution.     

Soil structural stability and erosion rates influenced by agricultural management practices in a semi‐arid Mediterranean agro‐ecosystem

Unsuitable agricultural practices can cause loss in soil quality and erodibility to thus increase or trigger desertification under Mediterranean conditions. A field experiment was performed at the El Teularet‐Sierra de Enguera Experimental Station (eastern Spain) to assess the influence during a 5‐yr period of different agricultural practices on physical and chemical indicators of soil quality (total and water‐soluble carbohydrates, glomalin‐related soil proteins (GRSP), total organic carbon, aggregate stability (AS), vegetation cover and soil erosion). The management practices included residual herbicide use, ploughing, ploughing + oats, addition of oat straw mulch and a control (land abandonment). Adjacent soil under natural vegetation was used as a reference for local, high‐quality soil and as a control for comparison with the agricultural soils under different management practices. Oat straw mulching led to higher levels of water‐soluble carbohydrates, GRSP and AS and lower soil erosion rates, resulting in values similar to those in the soil under native vegetation. The lowest levels of carbohydrates and GRSP were for the plots that were treated with herbicide or were ploughed. The maintenance of and increases in stable aggregates promoted by the different agricultural management practices over the years were attributed to increases in labile organic fractions such as carbohydrates and to the GRSP content. The results demonstrate that land abandonment (control plot) or the use of a cover (plants or straw) contributes to increases in soil quality and reduces the risk of erosion. The research also shows that sustainable agricultural management allows soil to recover and that the use of straw mulching is the most effective management strategy.     

Testicular damage from anabolic treatments with the beta(2)-adrenergic agonist clenbuterol in pigs: a light and electron microscope study

The morphological consequences of anabolic clenbuterol treatment on the testicular parenchyma were investigated in 30 pigs at morphological and ultrastructural levels. Clenbuterol was given with food (1 ppm). In the first group (n=10), treatment was maintained until slaughter (experimental period 3 months). In the second group (n=10), clenbuterol was withdrawn 2 weeks before slaughter (experimental period 2.5 months). A third group (n=10) of pigs not fed with clenbuterol served as controls. Animals were slaughtered at 9 months of age and samples of testicular parenchyma were collected for light and electron microscope studies. In the clenbuterol-treated groups, the interstitial cells showed a considerable increase in the organelles involved in testosterone production, with an increased development of the mitochondria, smooth endoplasmic reticulum, Golgi apparatus and lipid droplets compared to the control group. The seminal epithelium displayed many lipid vacuoles and evident signs of tubular involution, such as degenerating and multinucleate germ cells. Sertoli cells gave evidence of metabolic alterations such as large lipid deposits and cytolysosomes.     

Stereological study of the adrenal gland of calves treated with clenbuterol

Stereological methods were used to investigate the morphometric variations in the adrenal cell population of calves dosed orally with clenbuterol at an anabolic dose of 20 microg/kg bodyweight per day for 12 weeks. In the treated group the size of the nuclei increased with respect to the control group, and the increases were significant for the maximum linear parameters in all the regions except the zona fasciculata. The largest increases were observed in the epinephrine-producing cells. The quantitative stereological data showed highly significant increases in the nuclear volume fraction, the nuclear surface density and the numerical density in the zona fasciculata of the treated group.