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1.
2.
在丛生竹林下对不同基质配方和硒浓度菌棒进行埋棒栽培以及覆土方式栽培试验,结果表明,菌棒不同基质配方对竹荪产量及其营养成分有显著影响,而且三列浅沟形和双列龟背形2种覆土方式有利于提高竹荪产量。改良基质配方菌棒竹荪产量比常规配方提高约50%;在添加外源硒质量分数为0~2.0 mg/kg的浓度范围内,竹荪子实体产量先随着硒浓度的增加而逐渐增加后再有所降低,基质中添加1.5 mg/kg硒肥比不添加产量提高了195.30%。基质中添加硒质量分数为1.0~2.0 mg/kg的硒肥可以较显著地提高竹荪花的硒含量,其干物质中硒含量平均值从约2.50 mg/kg提高到8.05~13.30 mg/kg,外源硒肥利用率达到9.70%~15.36%。菌棒不同基质配方对竹荪子实体的粗蛋白及粗多糖含量有明显影响,改良配方竹荪蛋与竹荪花的粗蛋白含量是常规配方的1.21和1.29倍,其粗多糖含量是常规配方的4.81和1.35倍;基质中添加硒肥与不添加硒肥相比,竹荪蛋与竹荪花中粗蛋白含量分别增加了40.90%和14.30%。在硒质量分数为1.0 mg/kg的竹荪菌棒林下覆土栽培试验中,三列浅沟形覆土方式单位面积鲜竹荪蛋产量最高,为10.27 kg/m2;双列龟背形覆土方式单个菌棒的鲜竹荪蛋产量最高,达1.40 kg。三列浅沟形和双列龟背形2种覆土方式基质生物转化率分别为93.00%和94.14%,达到了较高水平。  相似文献   
3.
以狐尾藻(Myriophyllum verticillatum)为试验材料,采用液体培养法,研究了不同浓度Pb尾矿液单一胁迫下对其幼苗生长及生理指标的影响,以期为今后在探讨狐尾藻对Pb耐性机理方面提供参考依据和实践指导。结果表明:随着Pb尾矿渗出液单位浓度的升高,狐尾藻幼苗的株高和根长以及干质量整体呈不断下降趋势,其中,在100%Pb尾矿液处理下地下部的干质量较对照下降显著(P0.05)。此时,地上部干质量较对照也呈下降趋势,但整体幅度不大,说明狐尾藻幼苗的生长整体受到明显抑制;随着Pb尾矿渗出液单位浓度的升高,幼苗中光合色素含量逐渐下降且整体均低于对照。在纯Pb尾矿液处理条件下,Chla、Chlb和Car的含量比对照下降了14.6%、29.6%和23.2%;所有处理中幼苗地下及地上部相对电导率与Pb尾矿液浓度成正比且均高于对照。各个处理的地上及地下部Pro含量随着Pb尾矿液浓度增高整体呈上升趋势。其地上和地下部的AsA含量和GSH含量变化呈低浓度上升,高浓度下降的趋势。在25%Pb胁迫处理下,幼苗中AsA含量在地上和地下部均达到最高,与对照相比差异明显(P0.05),较对照增加了93.5%和89.8%。而地上和地下部GSH含量较对照增加了35.7%、4.36%。数据表明,狐尾藻对Pb胁迫下的环境有一定的抗性,可被用于Pb污染环境的生态修复。  相似文献   
4.
The important root characteristics of root length density (RLD) and root mass density (RMD) generally differ among irrigation managements and potato cultivars. The objective of this study was to investigate the RLD and RMD variations and their functional relationships with gross potato tuber yield for two commercial potato cultivars, Agria and Sante, under different irrigation strategies. Full irrigation and water‐saving irrigation strategies, deficit and partial root drying irrigations, were applied statically (S) and dynamically (D) based on daily crop evapotranspiration. Results showed that SPRD had significantly greater RLD (3.64 cm/cm3) and RMD (132.7 μg/cm3) than other irrigation treatments. Between the potato cultivars, Agria had significantly larger values of RLD (3.50 cm/cm3) and RMD (138.7 μg/cm3) than Sante. The functional relationship between the root growth characteristics and tuber yield showed that under water‐saving irrigations, Agria increased root mass at the expense of gross tuber yield but Sante increased root mass to maintain larger gross tuber yields. However, Agria produced more roots and gross tuber yield than Sante, and it is concluded that Agria is a more drought‐tolerant potato cultivar, which is recommended for tuber production in regions where water might be scarce. It was shown that larger root production in potatoes was associated with improved tolerance to water stress.  相似文献   
5.
通过对川西北地区的老井进行复查,发现多口井在上二叠统吴家坪组存在大套的凝灰岩,对上述井的地质、测井、地震资料综合分析发现,凝灰岩的岩性以凝灰质泥岩、凝灰质粉砂岩、凝灰质灰岩、沉凝灰岩、凝灰岩、凝灰质白云岩为主,次生溶蚀孔隙发育;凝灰岩在测井曲线和地震剖面上均有明显的响应特征:在测井曲线上表现为明显的低纵波速度、高自然伽马特征,凝灰岩底界在地震剖面上均表现为波峰反射特征.为此,采用模型正演分析技术及波阻抗反演技术,首次对四川盆地川西北地区晚二叠世吴家坪组凝灰岩的分布进行了地震预测:双鱼石构造-剑阁区块的北部地区凝灰岩分布最厚,南部减薄;双鱼石构造东部凝灰岩分布较厚,西部减薄,直至不发育.研究结果表明,晚二叠世吴家坪组在川西北地区沉积了一套凝灰岩,从西北至东南方向减薄;由于凝灰岩物性好,孔隙度高,可成为四川盆地火山岩气藏勘探全新的后备领域,为川西北地区下一步新的勘探领域开发提供了重要研究基础.  相似文献   
6.
“基础化学”理论和实验教学质量的“高与低”在一定程度上直接关乎高职院校与化学相近专业人才培养的“成与败”。以教学改革为切入点,在“基础化学”教材建设和系列微课的制作及应用2个维度上,探讨提升“基础化学”课程教学质量的具体措施。  相似文献   
7.
旨在估计山下黑猪和鲁莱黑猪正反交F1代杂种优势,筛选出合适的杂交方式,以提高优质肉猪的生产效率,满足人们对于优质猪肉的需求。本研究在山下黑猪(164头)和鲁莱黑猪(69头)及其正(6头山下黑猪♂×25头鲁莱黑猪♀)、反(3头鲁莱黑猪♂×35头山下黑猪♀)交4个群体中测定了生长肥育、体尺外貌(75~110 kg)、繁殖和胴体肉质(90~115 kg)4大类共43个性状,比较了这些性状在群体间的差异,并估计了正反交F1代的杂种优势。结果表明,山下黑猪的生长肥育和体尺性状较好,鲁莱黑猪的繁殖和肉质性状较好,正反交群体介于它们之间。正交群体的繁殖性能优于反交群体,但生长肥育性能比反交差。由于这4个群体的母猪都是纯种,因此繁殖性状没有表现出明显杂种优势。除膘厚、胸椎数、45 min pH和剪切力无显著的杂种优劣势外,大部分胴体性状和肉质性状有明显的杂种劣势。生长肥育性状的杂种优势在正反交群体中的表现不一致,反交群体表现出显著杂种优势,而正交则无明显的杂种优势。本研究估计了山下黑猪和鲁莱黑猪正反交的杂种优势,为筛选山下黑猪和鲁莱黑猪的最佳杂交方式奠定基础。  相似文献   
8.
To investigate the epizootic of swine influenza virus(SIV), 60 nasal swabs were collected from a clinical cases of pig farm in Tai'an City, Shandong Province of China in April 2017. SIV was isolated by inoculating into 10-day-old Special Pathogen Free embryonated eggs and the whole genome was sequenced. An H1N1 subtype SIV was isolated and designated as A/swine/Shandong/TA04/2017(H1N1). Phylogenetic analysis showed that apart from the polymerase A(PA) fragment belonging to the 2009 pandemic H1N1 branch, seven genome segments belonged to avian-like H1N1 influenza virus lineage. The cleavage site sequence of the hemagglutinin(HA) protein was PSIQSR↓G, which is a typical molecular biological characteristic. Five potential N-glycosylation sites(N14, N26, N277, N484 and N543) were found in the HA gene. To further investigate the epidemiology of SIV in this farm, the 995 serum samples were assessed with EAH1N1 2009 pandemic H1N1 and H3 N2 antigens. The results showed that the total positive rate was 65.43%. The positive rates of single virus infection detected by EAH1N1, 2009 pdmH1N1 and H3 N2 for serum HI(Hemagglutination inhibition) were 48.35, 30.85 and 7.47%, respectively. The results showed that SIV in Shandong Province has been reassorted in some segments and the SIV-positive rate was high on the SIV outbreak farm. These data provide evidence of an epizootic of SIV.  相似文献   
9.
To identify the possible quarantine viruses in seven common sunflower varieties imported from the United States of America and the Netherlands, we tested total RNAs extracted from the leaf tissues using next-generation sequencing of small RNAs. After analysis of small RNA sequencing data, no any quarantine virus was found, but a double-stranded RNA(dsRNA) molecule showing typical genomic features of endornavirus was detected in two varieties, X3939 and SH1108. Full-length sequence and phylogenetic analysis showed that it is a novel endornavirus, temporarily named as Helianthus annuus alphaendornavirus(HaEV). Its full genome corresponds to a 14 662-bp dsRNA segment, including a 21-nt 5′ untranslated region(UTR), 3' UTR ending with the unique sequence CCCCCCCC and lacking a poly(A) tail. An open reading frame(ORF) that encodes a deduced 4 867 amino acids(aa) polyprotein with three domains: RdRP, Hel and UGT(UDP-glycosyltransferase). HaEV mainly distributed in the cytoplasm but less in the nucleus of leaf cells by fluorescence in situ hybridization(FISH) experiment. This virus has a high seed infection rate in the five varieties, X3907, X3939, A231, SH1108 and SR1320. To our knowledge, this is the first report about the virus of the family Endornaviridae in the common sunflower.  相似文献   
10.
Pike (Esox lucius) occupy coastal streams and rivers of the Baltic Sea, where they attain large sizes (>5 kg). These large sizes are perhaps due to the fact that they can tolerate relatively high salinities and can thus forage in the nearby more productive brackish environments. In an attempt to quantify the extent to which pike utilise brackish environments, and to provide some insight into the underlying causes for brackish water migrations, we tagged 30 pike from a western Baltic river with acoustic transmitters and were able to track 21 individuals for 1 year. Based on experienced from local anglers, this population was assumed to be brackish in nature, where individuals underwent freshwater migrations to spawn. Our findings however suggest that the smallest and most active individuals make short exits into brackish waters and do so on rare occasions. Our results further indicate that neither sex nor size is related to activity level. We suggest that these patterns reflect two distinct behaviours—active and passive—and that large pike can be supported by the food availability in the river, without the need to venture into coastal zones, thus defying the conventional view that Baltic pike are all brackish in nature.  相似文献   
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