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911.
Nine sorghum cultivars (five inbred lines and four hybrids) were grown in 2006 in three locations (Mount Hope, KS, Halstead, KS, and Plainview, TX) under different irrigation conditions and were evaluated for composition and ethanol fermentation efficiency. The objective was to study, in one growing season, the effects of genotype, growing location, and irrigation on the physical and chemical properties and fermentation efficiencies of grain sorghum. Genotype had a significant effect on chemical composition, physical properties, and ethanol yield. The cultivars showed a large variation in starch (61.0–74.8%), protein (7.56–16.35%), crude fat (2.79–4.77%), crude fiber (0.58–2.57%), ash (1.25–2.26%), kernel weight (20.0–35.9 mg), kernel hardness (49.6–97.5), and kernel size (1.9–2.7 mm) and were the most important factors affecting ethanol fermentation efficiency (87.5–93.9%). Starch and protein contents were significantly affected by growing location but not by irrigation. Environment had a significant effect on ethanol yields. Unexpectedly, irrigation somewhat reduced fermentation efficiency.  相似文献   
912.
A feeding trial was conducted to determine the effect of dietary vitamin E supplementation on growth, liver lipid peroxidation and liver and muscle vitamin E level of soft‐shelled turtle, Pelodiscus sinensis. Eight experimental diets analysed to contain 0–457 IU vitamin E kg?1 were fed to juvenile soft‐shelled turtle of 4.8 g initial body weight for 12 weeks. Weight gain (WG) of the turtles fed the diet containing no vitamin E was significantly lower than those fed diets containing 83–457 IU vitamin E kg?1 (P<0.05). Feed conversion ratio and protein efficiency ratio showed similar trends to that of WG. No significant difference (P>0.05) was found in whole‐body composition among turtles fed the different diets. Dietary vitamin E requirement using WG as the response and estimated using the broken‐line regression model is approximately 88 IU kg?1. Liver and muscle vitamin E content increased when dietary vitamin E level increased. Ascorbate‐induced lipid peroxidation in liver tissue of turtles fed diets containing 0 and 17 IU vitamin E kg?1 was significantly (P<0.05) greater than those fed diets containing high vitamin E (≥35 IU kg?1).  相似文献   
913.
对甬江流域全部县、市(包括象山和宁海)32个乡镇88个采样点的淡水贝类作出了分类调查报告,标本经鉴定计49种,其中腹足纲32种、瓣鳃纲17种。分析了该流域淡水贝类的常见种和偶见种,广生种和狭生种。探讨了该流域淡水贝类的分布区划。  相似文献   
914.
为评价疏浚、吹填过程中产生的底泥悬浮物对南海区凡纳滨对虾仔虾的毒性影响,根据《水质-物质对淡水鱼(斑马鱼)急性致死毒性的测定》方法,对南海区凡纳滨对虾仔虾的生物毒性影响进行了分析。结果表明:疏浚区海水中底泥悬浮物浓度超过10mg/L,持续12h,对凡纳滨对虾仔虾产生一定的致死效应。底泥悬浮物浓度超高80mg/L,且持续48h以上,将对仔虾产生严重的影响,甚至导致全部仔虾的死亡。根据仔虾的死亡概率和底泥悬浮物浓度对数,分别计算出12h、24h、36h、48h的半致死量(LC50)为54.56、40.29、25.89、19.18mg/L。  相似文献   
915.
A new marine fish cell line, TK, derived from turbot (Scophthalmus maximus) kidney, was established by the method of trypsin digestion and subcultured for more than 50 passages over a period of 300 days. The TK cells were maintained in Minimum Essential Medium Eagle (MEM) supplemented with HEPES, antibiotics, fetal bovine serum (FBS), 2-Mercaptoethanol (2-Me), and basic fibroblast growth factor (bFGF). The suitable growth temperature for TK cells was 24°C, and microscopically, TK cells were composed of fibroblast-like cells. Chromosome analysis revealed that the TK cell line has a normal diploid karyotype with 2n = 44. Two fish viruses LCDV-C (lymphocystis disease virus from China) and TRBIV (turbot reddish body iridovirus) were used to determine the virus susceptibility of TK cell line. The TK cell line was found to be susceptible to TRBIV, and the infection was confirmed by cytopathic effect (CPE) and transmission electron microscopy, which detected the viral particles in the cytoplasm of virus-infected cells. Finally, significant green fluorescent signals were observed when the TK cells were transfected with pEGFP-N3 vector, indicating its potential utility for fish virus study and genetic manipulation.  相似文献   
916.
A feeding trial was conducted to determine the dietary folic acid requirement of juvenile grass shrimp, Penaeus monodon. Purified basal diets were formulated using vitamin-free casein as the protein source. Graded levels (0, 1, 2, 5, 10, 15, 30, and 60 mg folic acid/kg diet) of folic acid were added to the basal diet, resulting in eight dietary treatments in the experiment. Each diet was fed to three replicate groups of shrimp initially averaging 0.79±0.01 g for 8 weeks. Shrimp fed diets supplemented with 2 mg folic acid/kg diet had greater (P<0.05) weight gain and hepatopancreatic folic acid concentrations than shrimp fed the unsupplemented control diet. Feed efficiency (FE) was highest in shrimp fed the diets supplemented with 2 mg folic acid/kg diet, followed by the groups fed 1 mg/kg, then the control group. Hepatosomatic index (HSI) was highest in shrimp fed the control diet, followed by 1 mg folic acid/kg and lowest in shrimp fed diets supplemented with 2 mg folic acid/kg. Weight gain percentage, hepatopancreatic folic acid concentration and hepatosomatic index of the shrimp analyzed by broken-line regression indicated that the adequate dietary folic acid concentration in growing P. monodon is 1.9–2.1 mg/kg diet.  相似文献   
917.
本文采用涵养水源、保育土壤、固碳释氧、积累营养物质、净化大气环境和生物多样性保护等9个功能指标,对湖北省三峡地区天然林生态系统服务功能价值进行评估。结果表明:湖北省三峡地区天然林生态系统服务价值为336.66亿元·年-1。其中,固碳释氧、涵养水源和生物多样性保护3项功能价值量最大,分别占该地区天然林生态系统服务总价值的34.94%,30.45%和29.00%;阔叶林生态系统服务功能价值量最大,占该地区天然林生态系统服务总价值的37.54%。固碳释氧、涵养水源和生物多样性保护等功能都发挥着重要的作用,阔叶林在湖北省三峡地区天然林生态系统中具有突出的功能。  相似文献   
918.
河北省燕山区板栗害虫调查初报   总被引:3,自引:0,他引:3  
1997 ̄1999年,在河北省燕山板栗产区的遵化、兴隆、迁西等县(市)进行了板栗害虫的调查。经采集、饲养、现场拍照,结合有关资料鉴定、整理,初步确定板栗害虫、害螨共有129种,隶属于6个目46个科。  相似文献   
919.
三峡库区主要植被生物量与生产力分配特征   总被引:4,自引:1,他引:4  
在调查104块样地的基础上,利用95株标准木的树干解析数据,选择主要生物量生长模型,对三峡库区主要植被生物量和生产力的分配规律进行研究.结果表明:1)在各树种生物量组成中,干材生物量最大,占总生物量的44.46%~63.07%,而皮、枝和根生物量比例间的大小关系因树种不同而有所差异;2)所有树种干生物量比例与枝和叶生物量比例存在显著的线性负相关,而枝和叶生物量之间存在明显的正相关,随着单株林木生物量增加,针叶树种干和皮生物量比例会随之增加,但枝、叶和根的生物量比例则有所下降;3)各林分生物量为75.38~191.82t·hm-2,乔木层(67.57~179.00 t·hm-2)>枯落物层(3.95~11.61 t·hm-2)>灌木层(2.40~8.35 t·hm-2),乔木层和枯落物层生物量低,有利于灌木层生物量的生长;4)各林分生产力为4.78~11.07 t·hm-2a-1,常绿阔叶林最高,柏木林最低,混交林的生产力高于纯林,其中针阔混交林的生产力又高于针叶混交林.  相似文献   
920.
At present, our understanding of the dynamics of microbial biomass and soil N in silvopastoral systems is very limited. In this paper, the effects of understorey management on soil microbial C and N, net N mineralization, and net nitrification were studied in two seven-year-old radiata pine (Pinus radiata D. Don) – pasture systems, consisting of plots with and without ryegrass (Lolium perenne) as an understorey. Mini-plots (1 × 1 m) with animals excluded and herbage repeatedly clipped and removed were used for soil sampling. Three mini-plots formed a transect at each of two positions: 0.9 and 3.5 m north of the tree rows. Measurements were taken from July 1997 to June 1998 about once every 40 days. One composite sample was collected from each of two sampling depths (0–10 and 10–20 cm) at each transect position on each sampling date. Temporal and spatial variability of N mineralization rates and microbial biomass C and N was large. Net mineralization and nitrification rates were higher in the bare ground than in the ryegrass plots for a major part of the year, particularly from late spring to early fall. Net N mineralization and nitrification rates were higher in the 0–10 than in the 10–20 cm soil layers in both the ryegrass and bare ground treatments; however, the depth effect on microbial biomass C and N was only significant in the ryegrass treatment. In the surface soil layer, microbial biomass C and N were substantially greater in the ryegrass than in the bare ground plots. Soil microbial properties and activities were closely linked to pasture root activities, soil depth, and site biophysical conditions. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   
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