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41.
真鲷(Pagrosomus major)苗种生产技术的开发研究↑(*)   总被引:3,自引:0,他引:3  
1991-1993年在中国青岛市对真鲷苗种生产技术进行了连续三年的开发研究,通过改善亲鱼培育及采卵技术、提高轮虫连续培养及稳定供应技术、提高仔鱼开鳔率、加强饵料的营养强化、设置环流及水面集污器等技术措施、改进和完善了真鲷苗种生产工艺。利用 175m3培育水体,三年中共育出真鲷苗种 291. 6万尾,各年度的苗种生产量分别为 51.8万尾、116.4万尾、123.4万尾;培苗成活率分别为25.6%、32.8%、62.5%;平均单位水体出苗量分别为2960尾/m3、6651尾/m3、9872尾/m3。在国内首次实现苗种生产三年连续成功,并连续突破百万尾大关。同时试验证明利用对虾育苗池进行真纲苗种生产是可行的。  相似文献   
42.
几种生物混合制剂在古柏复壮中的作用   总被引:1,自引:0,他引:1  
雷增普  丛生 《园艺学报》1995,22(3):283-287
在古柏复壮试验中,用“5406”细胞分裂素、农抗120、农丰菌、增产菌、生物固氮肥的混合制剂进行叶面喷施和灌根处理,取得了良好效果,明显地促进了古柏枝叶及根系的生长;增加了枝叶叶绿素及磷的含量;增强了耐旱力;刺激了外生菌根的形成。  相似文献   
43.
Agroforestry Systems - Besides enabling economic activity, the domestication of indigenous species in situ configures a strategy for the conservation of genetic resources in Agroforestry Systems...  相似文献   
44.
Genetic Resources and Crop Evolution - This study aimed to evaluate the Mangaba Genebank of Embrapa Tabuleiros Costeiros, Brazil, since its implementation in 2006 and characterize the accessions in...  相似文献   
45.
对40例小型玩赏犬的眼结膜增生物(樱桃眼Cherryeye)发生的部位、病因、症状、病理组织学和治疗方法进行了较深入的观察和探讨,发现该病可以发生于犬的第三眼睑(瞬膜),也可发生于下眼睑结膜.该增生物是浆液性和粘液性的腺体增生组织,其组织结构和发生的规律符合良性单纯性腺瘤的特点,应予定名为犬眼结膜脉瘤.  相似文献   
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47.
Grain legume production is of great importance in the world economy, with soybeans being a major agricultural product. Among the main causes of crop losses are diseases caused by pathogens that infect seeds, such as Colletotrichum truncatum, Corynespora cassiicola, Sclerotinia sclerotiorum and Rhizoctonia solani. The fungicides used are not fully effective in controlling these diseases, and new control options are necessary. Photodynamic inactivation (PDI) may be an alternative. PDI consists of the association of a photosensitizer (PS), light and molecular oxygen aimed at the destruction of microbial cells. Porphyrins and their derivatives are aromatic tetrapyrrolic macrocyclic compounds with photosensitizing capacity. The aim of the present study was to evaluate the efficiency of PDI in the photoinactivation of C. truncatum, C. cassiicola, S. sclerotiorum and R. solani, using a mixture of cationic meso-tetra-aryl porphyrins as PS, being the first study to consider this formulation as PS in the photoinactivation of these pathogens. Assays were carried out with soybean seeds artificially inoculated with the different fungi, treated with the PS at 10, 50, 100 and 200 μg/ml and submitted to light under an irradiance of 50 mW/cm2. The assays were set up following the blotter test methodology. The evaluations showed significant reductions in the infection rates of the seeds in relation to the controls. The greatest reductions were 46% for C. truncatum, 95.5% for S. sclerotiorum, 87% for C. cassiicola and 92% for R. solani. The results suggest that PDI can be an important alternative to current control methods against these pathogens.  相似文献   
48.
This study evaluated the nutritional interrelationship between the growing and finishing phases of crossbred cattle in determining their performance. One hundred and eight animals were used (8 months old, body weight [BW] 211 ± 20 kg). During the dry season, the animals received one of the following supplements: a mineral plus urea supplement (ad libitum, MSD), a protein supplement (1 g/kg BW per day, PR1), or a protein-energy supplement (5 g/kg BW per day, PE). During the rainy season, the animals received one of the following supplements: a mineral without urea supplement (ad libitum, MSR), a protein supplement (1 g/kg BW per day, PR2), or PE (5 g/kg BW per day). The experimental design was completely randomized using a 3 × 3 factorial scheme (for the rainy season) and a 3 × 3 × 2 factorial scheme (for the finishing phase). The supplementation and finishing systems were considered to be the treatments, and the animals were considered to be the experimental units. Dry season supplementation did not affect the average daily gain (ADG) during the rainy season (P = 0.12) or the finishing phase (P = 0.73). An increase in the level of rainy season supplementation reduced ADG by 12% during the finishing phase (P < 0.06). Providing PE during the dry and rainy seasons led to the animals being slaughtered 17 (P = 0.06) and 30 (P < 0.01) days earlier, respectively. Our results indicate that supplementation during the dry season (under poor-quality pasture conditions) does not affect the performance during the rainy season or the finishing phase. Furthermore, while providing PE during the rainy season can reduce ADG during finishing, the higher BW at the beginning of the finishing phase is sufficient to reduce the time of the finishing period.  相似文献   
49.
Natural extracts, like those obtained from medicinal herbs, dietary plants and fruits are being recognized as important sources of bioactive compounds with several functionalities including antioxidant, anticancer, and antimicrobial activities. Plant extracts rich in phenolic antioxidants are currently being successfully used for several pharmaceutical applications and in the development of new foods (i.e., functional foods), in order to enhance the bioactivity of the products and to replace synthetic antioxidants. The extraction method applied in the recovery of the bioactive compounds from natural materials is a key factor to enhance the bioactivity of the extracts. However, most of the extraction techniques have to employ heat, which can easily lead to heat-sensitive compounds losing their biological activity, due to changes caused by temperature. Presently, high hydrostatic pressure (HHP) is being increasingly explored as a cold extraction method of bioactive compounds from natural sources. This non-thermal high hydrostatic pressure extraction (HHPE) technique allows one to reduce the extraction time and increase the extraction of natural beneficial ingredients, in terms of nutritional value and biological activities and thus enhance the bioactivity of the extracts. This review provides an updated and comprehensive overview on the extraction efficiency of HHPE for the production of natural extracts with enhanced bioactivity, based on the extraction yield, total content and individual composition of bioactive compounds, extraction selectivity, and biological activities of the different plant extracts, so far studied by extraction with this technique.  相似文献   
50.
High losses of nitrogen (N) by volatilization of ammonia from urea applied in Eucalyptus are expected due to the influence of plant residues on the soil surface. The study evaluated the N losses by volatilization of ammonia from urea coated with Thiophosphate N-(n-butil) triamide (NBPT) applied in soil with eucalyptus residues in surface under moisture treatments: fertilization in dry soil without irrigation; fertilization in dry soil with posterior irrigation depth (3 mm); fertilization in moist soil without irrigation and fertilization in moist soil with irrigation depth (3 mm). NBPT is a potential inhibitor of urease. Urea with NBPT shows lower losses by volatilization of ammonia when it is applied in dry soil; however in soil conditions of high moisture the losses as well as inhibitor effect of the NBPT are lower. The inhibitor effect of NBPT is reduced over time when it is subjected to moisture conditions.  相似文献   
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