Effect of met-myoglobin reductase on the color stability of blue fin tuna during refrigerated storage

ABSTRACT: To investigate the reducing ability of met-myoglobin (metMb) reductase, browned tuna meat was immersed with/without metMb reductase (0.103 unit/mL) for 120 min at 4°C. The metMb reductase activity of browned tuna meat significantly increased, whereas no significant change was observed in the control sample for the first 10 min of immersion ( P > 0.05). After comparing the changes in metMb reductase activity, metMb content, Hunter's 'a' and color, it was observed that the reductase did recover the bright red color. To further confirm the role of metMb reductase in color stability, fresh tuna meat was first immersed in metMb reductase (0.503 unit/mL) or a mixture of reductase and nicotinamide adenine dinucleotide (NADH) (1 mM) solutions at 5°C for 10 min, and then stored at 4°C and relative humidity 100%. No significant changes in metMb accumulation and in metMb reductase activity were observed between samples treated with enzyme alone and enzyme + NADPH ( P > 0.05). Changes in metMb reductase activity, metMb, Hunter's 'a' value and color for both the control and treated samples suggested that immersion in metMb reductase could extend the color stability of tuna meat, and that the enzymatic reduction of metMb by its reductase occurred during refrigerated storage.     

不同大麦品种抗旱性鉴定指标的筛选与评价

为筛选大麦抗旱性鉴定指标,通过隶属函数法对15个大麦品种13个农艺、生理、产量和品质性状的综合抗旱性进行了鉴定和评价分析。结果表明,产量、单株分蘖数、穗长、单株粒数和穗粒数5个性状的抗旱权重值与品种抗旱相关性较大;而叶片SPAD值及籽粒水分、淀粉和粗纤维含量4个性状与抗旱相关性较小。按隶属函数综合D值将15份参试大麦品种划分为4类,其中,沪麦4号、晋大麦（啤）3号和鄂大麦9号抗旱性较好。与抗旱系数和抗旱指数相比,隶属函数法能更全面地评价大麦品种抗旱性,为大麦抗旱新品种或新种质鉴定提供了理论参考。     

植物微生态学、植物微生态制剂与微生物肥料

论述了微生态学引起微生物学的观念革命及生态制剂的崛起,植物微生态学概念及发展历程;介绍了植物微生态制剂的筛选、作用机理、性能特点及应用效果;展望了植物微生态制剂的发展前景。     

遥感技术在沿海防护林中的应用

遥感技术是沿海防护林管理中的重要手段。文中概述了遥感技术在沿海防护林管理中的应用现状, 介绍了沿海防护林遥感的主要技术系统组成, 包括遥感数据源选择、沿海防护林遥感分类方法和分类精度评价等; 阐述了遥感技术在沿海防护林资源调查、动态监测和病虫害监测等领域中的应用以及当前基于遥感技术的沿海防护林的全球变化研究以及3S技术在沿海防护林管理中的综合应用; 指出目前存在的沿海防护林原始影像数据的选取、遥感分类精度以及沿海防护林遥感分类方法选择等问题, 展望了遥感技术在沿海防护林中的应用前景。     

湖北省早中熟花椰菜采种技术研究Ⅰ 高山采种生长发育过程观察

观察了花椰菜（Ｂｒａｓｉｃａｏｌｅｒａｃｅａｖａｒ．ｂｏｔｒｙｔｉｓ）三个早中熟品种在山区海拔８００～１４００ｍ采种的生长发育过程。结果表明：在高山地区春播进行早中熟花椰菜露地采种，能顺利完成生活史，总生育期随海拔高度增加而延长；各个生育期一般仍表现为温州５０天＜温州６０天＜温州８０天。各个生育期到来的时间一般随海拔高度的增加而延长。笔者认为长江流域高山区适宜进行早中熟花椰菜春播当年露地采种。     

Effect of diseases on the nutrient intake by suckling calves

An energy and protein intake test was applied to 341 female nursed calves under production conditions. Their daily intakes of skim milk enriched with milk substitute, fodder concentrates, and hay were recorded and their daily energy and protein intakes calculated. Their feed consumption was characterised by cumulative nutrient intake curves, depending on the time of foremilk feeding (K-I-period). Energy and protein intake figures were related to the findings obtained from daily health control, with the view to defining the effects of pneumonia or diarrhoea on feed intake. Both diseases were found to cause significant reduction in nutrient intake, depending on the given type of disease and severity, with their negative impact having been most markedly shown in the context of dry feed intake. The delay caused to the development of dry feed consumption by diseases of the respiratory and digestive tracts was many times longer than the time of the clinical course. The above observations provided some cues for conclusions regarding the approach to be taken by the veterinarian to diagnosis, therapy, and rehabilitation of affected calves. Certain concepts were derived from the findings as to how to feed calves to forestall developmental disorders.     

薄壳山核桃幼苗对干旱胁迫的生理生化响应

为探究薄壳山核桃幼苗对干旱胁迫的适应能力,本试验以一年生薄壳山核桃幼苗为材料,采用盆栽控水试验,设置正常供水(CK)、轻度干旱胁迫(LD)、中度干旱胁迫(MD)和重度干旱胁迫(SD)4种水分处理梯度,测定相关生理生化指标并分析叶片超微结构。结果表明,在干旱胁迫50 d时,随着干旱程度加剧,叶绿素a含量呈下降趋势,CK的叶绿素a含量分别是LD和MD的1.22和1.35倍;MD叶片气孔大量闭合,关闭密度达236 个·mm^-2;LD和MD的净光合速率(Pn)较CK分别下降了17.16%和58.42%。此外,渗透调节物质含量在干旱胁迫下显著提高,其中LD和MD的可溶性蛋白含量较CK分别增加了141.68%和204.17%。在干旱胁迫50 d时,MD幼苗的超氧化物歧化酶(SOD)活性达到峰值,为367.93 U·mg^-1prot,而过氧化物酶(POD)活性较干旱胁迫20 d出现下降。各水分梯度处理下,LD幼苗长势最好;MD叶片叶绿体结构破坏严重,基粒片层模糊不清;SD幼苗死亡,故为满足幼苗生长需要,应保证种植地土壤含水量达到田间持水量的35%以上。本研究结果为薄壳山核桃栽种区域的选择以及进一步扩大薄壳山核桃栽种面积提供了理论依据。     

氨氮降解微生物的筛选和初步应用

为了创制高效的粪污氨氮降解菌剂,特从猪粪中分离高效的氨氮降解微生物。通过感官法初筛,并结合氨氮降解率为指标进行复筛,最终获得高效氨氮降解菌株——Z2、AOZ和Y。经形态学观察、生理生化鉴定、16S rRNA基因序列分析,确定菌株Z2为弯曲芽孢杆菌(Bacillus flexus),菌株AOZ为恶臭假单胞菌(Pseudomonas putida),Y为干酪乳杆菌(Lactobacillus casei)。试验结果显示,菌株Z2和Y组成的复配菌剂对氨氮的降解效果最优,氨氮降解率高达53.19%,表明该复合菌剂可以应用于粪污除氨。     

晋江市沿海防护林20年景观生态格局变化研究

以福建晋江沿海防护林的5种主要类型为研究对象,从景观生态学的角度,运用RS和G IS技术,对1989年,1993年,2001年,2008年4个时相的遥感影像进行解译,结合实地调查,得到晋江市4个时相防护林的景观格局图。应用景观分析软件Fragstats,分别计算其景观格局指数并进行分析。结果表明:1989—1993年,5类防护林面积均明显减小,斑块密度增加,破碎化程度加大;1993—2001年,破碎化程度进一步加剧,而以农田防护林网最为明显;2001—2008年,防护林景观格局整体好转,但海岸基于林带仍呈下降趋势。说明基干林带一旦遭受破坏则很难恢复,应加强基干林带保护和建设。     

湖北省早中熟花椰菜采种技术研究Ⅱ海拔高度、播种期和种株密度对种子产量的影响

研究了海拔高度、播种期和种株密度对早中熟花椰菜采种种子产量的影响。结果表明：１）龙峰５０天、龙峰６０天的种子产量，海拔１４００ｍ处极显著地高于１０００ｍ、１２００ｍ处；龙峰８０天的种子产量海拔１２００ｍ处显著高于１０００ｍ、１４００ｍ处；２）３个品种的种子产量，３月１０日、４月１０日播种的极显著地高于５月１０日播种的；３）海拔高度×播种期的互作效应不显著；４）在５０ｃｍ×４０ｃｍ密度试验中，温州６０天的种子产量达６９０ｋｇ／ｈｍ２，极显著地高于５０ｃｍ×３３ｃｍ和５０ｃｍ×４７ｃｍ两种密度试验。