Xylogenesis of Pinus pinaster under a Mediterranean climate     

Joana Vieira  Sergio Rossi  Filipe Campelo  Helena Freitas  Cristina Nabais 《Annals of Forest Science》2014,71(1):71-80

Context

The knowledge on cambial activity in water-limited environments, such as the Mediterranean, is still fragmentary. Dendrochronological studies have determined that spring precipitation plays an important part in determining tree-ring width and the properties of tracheids. However, the complex relation between cambial phenology and climate is still far from understood.

Aims

We studied the influence of climate, especially water stress, on maritime pine wood formation with the aim of determining the influence of drought on cambial activity.

Methods

A plantation of maritime pine (Pinus pinaster) was selected in the west coast of Portugal, to monitor cambial activity and wood formation using anatomical observations and band dendrometers. The trees were monitored weekly over 2 years (2010 and 2011).

Results

Xylem differentiation started earlier when warmer late winter temperatures were observed. Water stress triggered an earlier stop of wood formation and also the formation of tracheids with smaller lumen area. In both years a bimodal pattern of stem radial increment was registered by band dendrometers with two periods of increment: one in spring and another in autumn. The xylem anatomy study suggests that the autumnal increment period corresponded mostly to stem rehydration, since the differentiation of new xylem cells by the cambium was not observed.

Conclusion

Maritime pine cambial activity appears to be under a double climatic control: temperature influences cambial onset and water availability growth cessation.  相似文献   

Induced spawning of hatchery-raised Brazilian catfish, cachara Pseudoplatystoma fasciatum (Linnaeus, 1766)     

Antnio Fernando Gervsio Leonardo  Elizabeth Romagosa  Maria Inês Borella  Sergio Ricardo Batlouni 《Aquaculture (Amsterdam, Netherlands)》2004,240(1-4):451-461

In the months of January 2001 and 2002, female cachara Pseudoplatystoma fasciatum were selected during their first and second gonadal maturation (2 years and 7 months old and 3 years and 7 months old, respectively) with an of oocyte diameter of 937.5 μm (82.5% with central nuclei and 17.5% with peripheral nuclei). Nine females in first maturation received two doses of carp pituitary extract (CPE), 0.5 mg/kg and 5.0 mg/kg; seven received two doses of human chorionic gonadotropin (hCG), 5 and 10 IU/g; five received doses of 0.5 CPE mg/kg and 5 hCG IU/g (CPE+hCG); and four received 0.9% saline (saline). Nine females from CPE and seven from hCG presented oocytes with the same diameter at the moment of oocyte release (100% with germinal vesicle breakdown and fertilization rate of 53.44±18.3 and 54.81±11.8%; larvae number of 165,330±94.1 and 158,570±20.6, respectively). The five females from CPE+hCG did not respond to the hormonal treatment. The four females from the saline group did not ovulate. In January 2002, 6 of 15 selected females that were going through the second reproductive cycle received CPE (five received hCG and four received saline), showing oocyte diameters similar to the ones in the first maturation. At stripping, CPE females had an oocyte diameter of 1062.5 μm (the hCG females had oocyte diameters ranging from 937.5 to 1125.0 μm; fertilization rates of 56.08±30.9 and 81.90±17.3%; 364,547±244 and 633,129±190, larvae, respectively). The fertilization rates and larvae number were higher in the second gonad maturation, both for CPE and hCG.  相似文献   

Comparison of Regular and Selenium-Enriched Tortillas Produced from Sprouted Corn Kernels     

Guardado-Félix  Daniela  Pérez-Carrillo  Esther  Heredia-Olea  Erick  Serna-Saldivar  Sergio O. 《Plant foods for human nutrition (Dordrecht, Netherlands)》2022,77(2):226-232

Plant Foods for Human Nutrition - Corn kernels were soaked with different selenium (Se) solutions (0, 12 or 24 mg Na2SeO3/L), sprouted for different times and then lime-cooked for the...  相似文献   

Heavy Metal Contents and Distribution in Coastal Sediments of the Gulf of Trieste (Northern Adriatic Sea, Italy)     

Alessandro Acquavita  Sergio Predonzani  Giorgio Mattassi  Pietro Rossin  Francesco Tamberlich  Jari Falomo  Iztok Valic 《Water, air, and soil pollution》2010,211(1-4):95-111

A set of ten heavy metals (Al, As, Cd, Cr, Cu, Hg, Ni, Pb, V, and Zn) was investigated in surface sediments (0–5 cm) collected in 21 sites of the Gulf of Trieste, Northern Adriatic Sea (Italy). The aim of this work was to obtain a preliminary assessment about the levels and spatial distribution of these selected elements. Ancillary parameters such as grain size, total organic carbon, and total nitrogen were also determined. The enrichment factor was calculated to discriminate if a natural condition or a status of anthropogenic contamination occurs. In addition, a set of sediment quality guidelines, mean effect low range and effect medium range quotients, was also applied in order to predict the probability of adverse biological effects on the benthic community.  相似文献   

Studies on the Nutrition of Spotted Sand Bass Paralabrax maculatofasciatus: Effect of the Dietary Protein Level on Growth and Protein Utilization in Juveniles Fed Semipurified Diets     

Benjamín H.  Anguas-Vélez Roberto  Civera-Cerecedo Marco  Cadena-Roa Jean  Guillaume Sergio F.  Martínez-Díaz 《Journal of the World Aquaculture Society》2000,31(4):580-591

Two feeding trials were conducted to determine the digestibility of a casein-based semi-purified diet and the effects of different protein levels on growth and protein use of spotted sand bass Paralabrax maculatofasciatus juveniles. For trial I, a semipurified diet with vitamin-free casein as the sole source of protein was fed three times a day to apparent satiation, for a period of 20 d. Feces were collected by siphoning each tank. The digestibility of the experimental diet was high: 97% for protein, 89% for lipids, and 84% for gross energy, whereas that of organic matter was 78%. For trial II, seven diets were formulated using vitamin-free casein at graded levels (25, 30, 35, 40, 45, 50, and 55% protein). Triplicate tanks for each dietary treatment were stocked with fish and fed by hand three times a day to apparent satiation for 6 wk. Perfomance of fish fed the different diets was evaluated for survival, percent weight gain, specific growth rate, feed conversion ratio, and protein efficiency ratio. Survival was 100% for all treatments. Growth of spotted sand bass juveniles increased as the dietary protein increased, but no evidence of reaching a plateau was found. The daily feed intake values showed an inverse relation to the protein content of the diets. The feed conversion ratio did not differ among diets containing 40% protein or greater. The results indicate that spotted sand bass juveniles with 2.5-g mean weight need at least 55% dietary protein for best growth when casein is the sole protein source. However, in terms of feed conversion ratio, the requirement apparently could be lower.  相似文献   

Screening wild plants of Capsicum annuum for resistance to pepper huasteco virus (PHV): Presence of viral DNA and differentiation among populations     

Sergio Hernández-Verdugo  Ramón G. Guevara-González  Rafael F. Rivera-Bustamante  Ken Oyama 《Euphytica》2001,122(1):31-36

Plants collected in thirteen wild populations of Capsicum annuum from Northwest Mexico were tested for resistance to the pepper huasteco begomovirus (formerly subgroup III) (PHV) that is transmitted by the white fly Bemisia tabaci Genadius. Plants were inoculated using both grafting and biolistic methods. Presence of viral DNA was detected by dot blot hybridization and densitometry. Populations varied in their resistance to PHV. Plants of only two of the populations either did not develop disease symptoms or showed very light symptoms after inoculation. In some cases, symptoms appeared several days after inoculation. In plants of these populations viral DNA was detected by dot-blot hybridization assays but they appear to be a good source of resistance (symptomless) for use in breeding programmes. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

Chromosomal structural changes in Capsicum annuum L. and C. chinense Jacq.     

Sergio Lanteri  Barbara Pickersgill 《Euphytica》1993,69(1-2):155-160

Summary Wide hybridizations between M. arvensis and Brassica amphidiploid species (B. napus and B. juncea) were carried out in order to incorporate desirable traits of M. arvensis into Brassica crops. Crossing barriers between them were present without the use of in vitro techniques. F₁ hybrids have been produced through ovary culture, when M. arvensis were used as a female parent. Higher hybrid embryo productivity (3.07 embryos per pollination) was obtained in the cross of M. arvensis x B. napus than in that of M. arvensis x B. juncea (0.79 embryos). The hybridity was confirmed by morphology, cytology, isozyme and Southern analyses. The first backcrossing progenies and open pollinated ones were produced.  相似文献   

Classification of Ilex species based on metabolomic fingerprinting using nuclear magnetic resonance and multivariate data analysis     

Choi YH  Sertic S  Kim HK  Wilson EG  Michopoulos F  Lefeber AW  Erkelens C  Prat Kricun SD  Verpoorte R 《Journal of agricultural and food chemistry》2005,53(4):1237-1245

The metabolomic analysis of 11 Ilex species, I. argentina, I. brasiliensis, I. brevicuspis, I. dumosavar. dumosa, I. dumosa var. guaranina, I. integerrima, I. microdonta, I. paraguariensis var. paraguariensis, I. pseudobuxus, I. taubertiana, and I. theezans, was carried out by NMR spectroscopy and multivariate data analysis. The analysis using principal component analysis and classification of the (1)H NMR spectra showed a clear discrimination of those samples based on the metabolites present in the organic and aqueous fractions. The major metabolites that contribute to the discrimination are arbutin, caffeine, phenylpropanoids, and theobromine. Among those metabolites, arbutin, which has not been reported yet as a constituent of Ilex species, was found to be a biomarker for I. argentina,I. brasiliensis, I. brevicuspis, I. integerrima, I. microdonta, I. pseudobuxus, I. taubertiana, and I. theezans. This reliable method based on the determination of a large number of metabolites makes the chemotaxonomical analysis of Ilex species possible.  相似文献   

Nitrogen-fixing legume tree species for the reclamation of severely degraded lands in Brazil     

Chaer GM  Resende AS  Campello EF  de Faria SM  Boddey RM 《Tree physiology》2011,31(2):139-149

The main challenges faced in the reclamation of severely degraded lands are in the management of the systems and finding plant species that will grow under the harsh conditions common in degraded soils. This is especially important in extremely adverse situations found in some substrates from mining activities or soils that have lost their upper horizons. Under these conditions, recolonization of the area by native vegetation through natural succession processes may be extremely limited. Once the main physical and chemical factors restrictive to plant growth are corrected or attenuated, the introduction of leguminous trees able to form symbioses with nodulating N?-fixing bacteria and arbuscular mycorrhizal fungi constitutes an efficient strategy to accelerate soil reclamation and initiate natural succession. These symbioses give the legume species a superior capacity to grow quickly in poor substrates and to withstand the harsh conditions presented in degraded soils. In this article we describe several successful results in Brazil using N?-fixing legume tree species for reclamation of areas degraded by soil erosion, construction and mining activities, emphasizing the potential of the technique to recover soil organic matter levels and restore ecosystem biodiversity and other environmental functions.  相似文献   

Changes in phenolic composition and antioxidant activity of virgin olive oil during frying   总被引：2，自引：0，他引：2  

Gómez-Alonso S  Fregapane G  Salvador MD  Gordon MH 《Journal of agricultural and food chemistry》2003,51(3):667-672

The concentration of hydroxytyrosol (3,4-DHPEA) and its secoiridoid derivatives (3,4-DHPEA-EDA and 3,4-DHPEA-EA) in virgin olive oil decreased rapidly when the oil was repeatedly used for preparing french fries in deep-fat frying operations. At the end of the first frying process (10 min at 180 degrees C), the concentration of the dihydroxyphenol components was reduced to 50-60% of the original value, and after six frying operations only about 10% of the initial components remained. However, tyrosol (p-HPEA) and its derivatives (p-HPEA-EDA and p-HPEA-EA) in the oil were much more stable during 12 frying operations. The reduction in their original concentration was much smaller than that for hydroxytyrosol and its derivatives and showed a roughly linear relationship with the number of frying operations. The antioxidant activity of the phenolic extract measured using the DPPH test rapidly diminished during the first six frying processes, from a total antioxidant activity higher than 740 micromol of Trolox/kg down to less than 250 micromol/kg. On the other hand, the concentration of polar compounds, oxidized triacylglycerol monomers (oxTGs), dimeric TGs, and polymerized TGs rapidly increased from the sixth frying operation onward, when the antioxidant activity of the phenolic extract was very low, and as a consequence the oil was much more susceptible to oxidation. The loss of antioxidant activity in the phenolic fraction due to deep-fat frying was confirmed by the storage oil and oil-in-water emulsions containing added extracts from olive oil used for 12 frying operations.  相似文献