排序方式: 共有67条查询结果,搜索用时 78 毫秒
21.
Hanane Djelailia Rachid Bouraoui Bayrem Jemmali Taha Najar 《Reproduction in domestic animals》2020,55(9):1250-1257
This work aims to study the relationship between variations of the Temperature-Humidity Index (THI) and the parameters of reproduction especially the first conception rate (FCR) and to determine the threshold THI value where cows’ fertility rate dropped in 12 Holstein dairy herds raised in the arid climatic conditions of Tunisia. THI values were calculated over 22 years (1996–2018), and the mean monthly temperature and relative humidity data were obtained from the Meteorological Institute of Tunisia. A total of 20,396 individual records (Insemination and calving dates) were extracted from the Livestock and Pasturing Office (OEP, Tunisia) with regard to the highest THI before breeding, on the breeding day, and after breeding. Statistical analysis was performed using the GLM procedure of SAS software. Results point to the fact that a summer heat stress exists in southeast Tunisia and lasts for 4 months starting from June until September with THI values fluctuating between 73 ± 2.38 and 79 ± 3.01 exceeding, therefore, THI threshold of 72. Increased THI from ≤70 to ≥80 units was associated with drops in conception rate (CR) and fertility rate (FR) of 49% and 45% giving a correlation with the THI of (r = −.72, p < .05) and (r = −.74, p < .05), respectively. When cows were inseminated on extremely hot days (THI ≥ 80) preceded by cooler temperatures, pregnancy by service (P/AI) was 7% points higher than for other cows that were exposed to high temperatures before breeding. The average number of insemination was higher (p < .05) from THI ≤ 70 (2.01) compared to THI ≥ 80 (3.41). Cows calving during an absence of heat stress (THI ≤ 70) have the shortest average calving intervals (CI: 420 ± 15.1 days). Contrastly, calving in the condition of heat stress (THI ≥ 80) has the longest CI (487 ± 12.8 days). For each point increase in the THI value above 67, there is a decrease in the first conception rate by 1.39%. In this particular arid environment, high-yielding Holstein cows’ breeding success is strongly affected by heat stress that takes place just before or after breeding. 相似文献
22.
Bel Rhlid R Fleury Y Blank I Fay LB Welti DH Arce Vera F Juillerat MA 《Journal of agricultural and food chemistry》2002,50(8):2350-2355
Roasted notes contribute to the flavor of thermally processed foods such as meat and bread. 2-Acetyl-2-thiazoline is one of the key volatile compounds responsible for the roasted and popcorn-like aroma character. We report here on the biogeneration of flavoring preparations with intense roasted notes, which are characterized by a high content of 2-acetyl-2-thiazoline. These flavoring preparations were obtained by fermentation of cysteamine, ethyl-L-lactate, and D-glucose with baker's yeast. The precursor of 2-acetyl-2-thiazoline, 2-(1-hydroxyethyl)-4,5-dihydrothiazole, was prepared under mild conditions by microbial reduction of the carbonyl group of 2-acetyl-2-thiazoline using baker's yeast as biocatalyst. The addition of 2-(1-hydroxyethyl)-4,5-dihydrothiazole as aroma precursor to pizza dough resulted in an increase of the roasted note. 相似文献
23.
Genetic variability of drought-avoidance root traits in the mini-core germplasm collection of chickpea (Cicer arietinum L.). 总被引:2,自引:0,他引:2
Junichi?KashiwagiEmail author L.?Krishnamurthy Hari?D.?Upadhyaya Hari?Krishna S.?Chandra Vincent?Vadez Rachid?Serraj 《Euphytica》2005,146(3):213-222
Extensive and deep root systems have been recognized as one of the most important traits for improving chickpea (Cicer arietinum L.) productivity under progressively receding soil moisture conditions. However, available information on the range of variation
for root traits is still limited. Genetic variability for the root traits was investigated using a cylinder culture system
during two consecutive growth seasons in the mini-core germplasm collection of ICRISAT plus several wild relatives of chickpea.
The largest genetic variability was observed at 35 days after sowing for root length density (RLD) (heritability, h
2 = 0.51 and 0.54) across seasons, and followed by the ratio of plant dry weight to root length density with h
2 of 0.37 and 0.50 for first and second season, respectively. The root growth of chickpea wild relatives was relatively poor
compared to C. arietinum, except in case of C. reticulatum. An outstanding genotype, ICC 8261, which had the largest RLD and one of the deepest root system, was identified in chickpea
mini-core germplasm collection. The accession ICC 4958 which was previously characterized as a source for drought avoidance
in chickpea was confirmed as one with the most prolific and deep root system, although many superior accessions were also
identified. The chickpea landraces collected from the Mediterranean and the west Asian region showed a significantly larger
RLD than those from the south Asian region. In addition, the landraces originating from central Asia (former Soviet Union),
characterized by arid agro-climatic conditions, also showed relatively larger RLD. As these regions are under-represented
in the chickpea collection, they might be interesting areas for further germplasm exploration to identify new landraces with
large RLD. The information on the genetic variability of chickpea root traits provides valuable baseline knowledge for further
progress on the selection and breeding for drought avoidance root traits in chickpea. 相似文献
24.
Rachid RAZOUK Abdellah KAJJI Anas HAMDANI Jamal CHARAFI Lahcen HSSAINI Said BOUDA 《农业科学与工程前沿(英文版)》2021,8(4):583
25.
Akroud Hayat Sbaghi Mohamed Bouharroud Rachid Koussa Tayeb Boujghagh Mohamed El Bouhssini Mustapha 《Phytoparasitica》2021,49(4):623-631
Phytoparasitica - The wild cochineal, Dactylopius opuntiae (Cockerell), has become the main pest of the prickly pear [(Opuntia ficus-indica (L.) Miller] cactus crop in most of the Mediterranean... 相似文献
26.
Lahlali Rachid Jaouad Manal Moinina Alieu Mokrini Fouad Belabess Zineb 《植物病害和植物保护杂志》2021,128(5):1213-1226
Journal of Plant Diseases and Protection - This paper documents pest management practices adopted by citrus farmers in two of the citrus-growing regions in Morocco. The survey data propose possible... 相似文献
27.
Basaid Khadija Chebli Bouchra Bouharroud Rachid Elaini Rachid Alaoui Ilyass Filali Kaoui Soukaina de Oliveira Alessandra Lopes Furze James Nicholas Mayad El Hassan 《植物病害和植物保护杂志》2021,128(5):1157-1166
Journal of Plant Diseases and Protection - The present study characterized and evaluated the antifungal, nematicidal, acaricidal and repellent activities of Ridolfia segetum essential oil (EO),... 相似文献
28.
Abstract A programme for the biological control of the citrus leafminer Phyllocnistis citrella Stainton (Lepidoptera, Gracillariidae) was carried out in Tunisia between 1996 and 1998. Two exotic parasitoids, Ageniaspis citricola (Logvinovskaya) (Hymenoptera, Encyrtidae) and Semielacher petiolatus Girault (Hymenoptera, Eulophidae), were introduced from Australia, mass-reared in a greenhouse on Citrus aurantium L. seedlings infested with P. citrella, and released in different orchards located in the major citrus-growing area of Tunisia. In 1996, A. citricola was recovered in 39.13% of release sites, reaching a maximum percentage of parasitism of 28%. In 1997, the parasitoid was recovered in a third of all release points, with an average percentage of parasitism of 5%. However, the wasp was unable to survive the winter 1998, and has become extinct. The non-establishment of A. citricola may have been due to the more arid climatic conditions present during the rainless summer and most of the autumn in Tunisia. By contrast, the establishment, dispersal, and reduction in citrus leafminer population observed with S. petiolatus between 1997 and 1998 shows this species to be well-adapted to the Tunisian climate. The average percentage parasitism of P. citrella by S. petiolatus increased from 6.6% in 1997 to 15% in 1998. Moreover, S. petiolatus was established in 76% of release points in 1997 and in 82% in 1998. It spread as much as 30 km from some release points, with no apparent decline in parasitism levels with distance. Semielacher petiolatus is considered to be an effective biological control of the leafminer in Tunisia. Its biological control action would supplement the action of the native parasitoids Pnigalio sp. and Cirrospilus pictus Nees (Hymenoptera, Eulophidae). 相似文献
29.
Fatima Benlboukht Loubna El Fels Rachid Bouamri Soumia Amir 《Compost science & utilization》2016,24(3):208-218
Changes in the structural composition of fulvic acids were followed during composting of tannery solid waste after neutralization of its acidity by ammonium or by lime. Different techniques (elemental analysis, Fourier transform infrared (FTIR), 13C-NMR spectroscopy) were applied. During both trials of composting, a decrease of carbon and increase of oxygen occurred, which originated from strong microbial oxidation and preservation of some structures during composting. In fact, Nuclear Magnetic Resonance (NMR) spectra showed the preservation of anomeric or tannin structures around 105 ppm. The infrared (IR) spectral data showed a decrease in the intensity of COO? group bands (1623 and 1399.5 cm?1); this is correlated with a decrease of fulvic acid levels. The variations observed in NMR spectra could be explained by the involvement of COO? groups of certain structures in polycondensing to form humic acids. The fulvic acids remain composed of less polycondensed structures with a –COOH extremity, as supported by a decrease of the C/H ratio. In contrast, in the trial with addition of ammonia a slight increase in N content occurred, a decrease in absorbance in the 1730–1000 cm?1 regions compared to the absorbance around 3400 cm?1, and a strong decrease of carboxyl carbon in the 13C-NMR spectra. 相似文献
30.
Francis B. T. Silatsa Martin Yemefack Nathalie Ewane-Nonga Adoph Kemga Rachid Hanna 《Agroforestry Systems》2017,91(5):993-1006
With increasing concerns raised by climate change, understanding biological processes within cocoa (Theobroma cacao L.) agroforest (CAF) and fallow systems is a prerequisite for developing actions related to emission reduction in the shifting agricultural landscape of Cameroon. Carbon (C) stocks and accretion were assessed and modeled in various C components (large trees, small trees, dead wood, litter, roots, soil, and total C) of fallow and CAF systems along a 50-year chronosequence. Several functions were empirically fitted to a time series of C stocks. Large tree, soil, and total C stocks were best described by a logistic growth function while that for small trees by a rational quadratic function. The best-fitted functions explained 72–96 % of C stock accumulation over time. Two metrics describing C stock accretion were derived from these functions: the point of maximum C growth and the C growth coefficient (GC). The rate of maximum growth of total C stock was reached after 12–13 years in both fallow and CAF, with maximum GCs of 6.9 and 6.3 Mg C ha?1 year?1, respectively. Over the 50-year period, the GCs of total C stocks varied between 0.2 and 6.9 Mg C ha?1 year?1, with quick accumulation within the first decade that then slowed until it levelled off after 45 years. Over a period of about 30 years, both systems sequestered a total of ~200 Mg C ha?1. This indicates that cocoa agroforests, a main source of income for local populations, can also provide significant climate change mitigation services. 相似文献