Changes of proximate compositions and myoglobin content in the dorsal ordinary muscles of the cultured Pacific bluefin tuna <Emphasis Type="Italic">Thunnus orientalis</Emphasis> with growth

ABSTRACT:   Using the dorsal ordinary muscle (DOM) of cultured Pacific bluefin tuna (body length [BL]: 47.5–81.8 cm, body weight [BW]: 2.1–13.5 kg, n  = 15), the changes of proximate compositions and myoglobin (Mb) content with growth were investigated. There was a positive correlation ( r  = 0.9832, P  < 0.05) of BL and BW in cultured tuna. The protein contents of the DOM of cultured tuna decreased ( P  < 0.05) and the lipid contents had a tendency to increase (not significantly) with growth. The meat color changed from pink to red with growth. In addition, the Mb contents of the DOM of cultured tuna increased ( P  < 0.05) from 1.0 mg/g (minimum BW fish) to 3.8 mg/g (maximum BW fish) with growth. These results indicate that the increase of the Mb content in the DOM of cultured tuna is not caused by the restriction of exercise and overfeeding between 2.1 kg and 13.5 kg of BW.     

不同密度与追肥种类对大白菜夏秋栽培的影响

研究了４种栽植密度与３种追肥种类对大白菜夏秋栽培产量和产值的影响，结果表明，栽培密度是影响大白菜丰产的主要因素，追肥种类对产量影响不大，从产量、产值上综合考虑以４２００株／６６７ｍ＾２和选用尿素１：１５０追肥的栽培处理最好。     

草业发展的人才培养对策

草业是一个新兴的产业部门。大力发展草业是社会主义建设和人民生活所必须。我国是一个草原大国，草业资源丰富，但生产水平甚低，效益差，重要原因是草业科技不发达，人才奇缺。作者从人才培养和发展草业的关系的角度，认为人才培养是发展草业的关键。提出了如何办好草业学院及院系与科研所联合，共同培养草业人才的构想。     

猕猴桃试管苗移栽条件研究

在普通塑料大棚内，对影响猕猴桃试管苗移栽成活的因素进行研究，结果表明，空气湿度、温度、移栽季节是影响试管苗成活的关键因子，同时充分的炼苗也是获得高成活率的必要条件。在移栽1－15d内，空气湿度保持在90％以上，能获得较高的成活率。适宜的移栽温度为8－22℃较适宜。移栽基质为沙：土：粪＝2：1：1的复合土；除夏季高温时期成活率低外，其余季节均可进行移栽，而以冬季移栽成活率最高。     

Sucrose transporter NtSUT1 confers aluminum tolerance on cultured cells of tobacco (Nicotiana tabacum L.)

The role of plasma membrane-localized sucrose transporter (NtSUT1) was investigated using cultured tobacco cell (Nicotiana tabacum L.) line BY-2. The wild type (WT) cells were first transformed with the NtSUT1 gene or its fragments cloned from tobacco cell line SL to form the over-expression (OX) and suppression (RNAi) cell lines, respectively. Using OX and RNAi transgenics, the role of NtSUT1 in growth capacity of actively growing cells and in aluminum (Al)-treated cells was examined. During the logarithmic phase of growth in nutrient medium containing 2,4-dichlorophenoxyacetic acid (2,4-D), both the rate of sucrose uptake measured with radio-tracer and the content of soluble sugars were higher in OX and lower in RNAi cell lines compared to WT. Overall, the content of soluble sugars negatively correlated with the time necessary for doubling mass (fresh weight). When cells were treated without (control) or with Al in a simple medium containing calcium, sucrose and 2-(N-morpholino)ethanesulfonic acid (MES; pH 5.0) for up to 18 h, the expression of NtSUT1 under its native promoter, or under the control of strong constitutive cauliflower mosaic virus (CaMV) 35S promoter, was strongly dependent on the presence of 2,4-D. Thereafter, the cells were preferentially treated in the presence of 2,4-D. During 6 h after a start of the control treatment, sucrose uptake rates were, compared to WT, slightly higher and lower in OX and RNAi lines respectively. The addition of Al reduced the sucrose uptake rates of OX and WT to the level of RNAi line, indicating that Al inhibits sucrose uptake via NtSUT1. During the post-Al culture of control and Al-treated cells in a nutrient medium, sucrose uptake rates were much higher in OX compared to WT and RNAi lines, which closely and positively correlated with the growth capacity of the cells. Judging from the growth capacity of Al-treated cells relative to that of control cells, OX cells were more tolerant to Al than WT and RNAi. In summary, we conclude that over-expression of NtSUT1 confers higher growth capacity in actively growing cells as well as in Al-treated cells.     

不同贮藏温度下养殖大黄鱼货架期预测模型的构建

为探讨不同温度范围内导致产品腐败的原因和开发货架期预测模型,通过对低温(0～10℃)、室温(25℃)和变温贮藏下养殖大黄鱼感官、理化和微生物质量指标和细菌种群的研究,确定上述温度条件下的货架期和特定腐败菌,开发出3种货架期预测模型,并用恒温和波动温度下的货架期进行验证。结果表明,养殖大黄鱼低温下的货架期为5.4～17.8d,特定腐败菌为腐败希瓦氏菌和假单胞菌,室温下货架期仅1.1d,特定腐败菌为弧菌和肠杆菌。依据相对腐败速率与温度的相关性,开发出Exponential、School-field和Square-root货架期预测模型,模型参数表观活化能Ea、最小温度Tmin和温度特性系数a分别为74kJ/mol、-10℃和0.11,并用3、7、10℃恒温和变温下的货架期对模型进行验证,相对误差分别为0%～13.8%、-0.9%～9.8%和-0.2%～-22.1%,表明School-field和Exponential货架期模型性能优于Square-root货架期模型,能快速有效预测0～25℃范围的大黄鱼品质。该文将为进一步研发集包装、贮藏和流通等为一体的水产品品质智能化预警系统提供依据。     

不同栽培基质对平菇产量和性状的影响

为适应食用菌产业的迅猛发展,开发新型基质以满足平菇生产的需求,以不同含量的麻屑、豆秸及菌渣为栽培基质,栽培平菇灰美二号,研究不同基质对平菇产量和性状的影响。结果表明:不同配方下的平菇子实体形态无明显变化,以麻屑、豆秸和木耳菌渣为基质主料栽培平菇是可行的,其中豆秸45%+菌渣40%(配方3)和麻屑40%+菌渣45%(配方7)与对照相比,子实体生长健壮,生物学效率高,经济效益高。     

不同栽培基质对4种姜科花卉组培苗移栽成活和生长的影响

用5种栽培基质移栽姜黄、郁金、温郁金和花叶艳山姜4种姜科花卉组培苗,试验结果表明:4种姜科花卉组培苗在不同基质中的移栽成活率不同,其中,姜黄和温郁金对环境适应性相对较强、郁金次之、花叶艳山姜较差;不同基质对组培苗的移栽效果不同,其中,椰糠和营养土处理较适合组培苗生长,组培苗的成活率、株高、叶片数、新叶宽和根数多优于其他处理。     

淡水养殖珍珠棱柱层的微结构形貌特征

通过x射线粉晶衍射（XRD）、场发射扫描电镜（FE—SEM）对不同颜色的淡水养殖珍珠的微结构进行较系统研究。结果表明,质优的珍珠其矿物相为文石,未见有方解石或球文石相,不同颜色的珍珠质层文石板片的厚度存在较大差异。质量较好的珍珠中接近珍珠核心区域存在棱柱层,该棱柱层由众多的纤维或条带状文石结晶体聚集而成,其中文石纤维或条带的定向近平行于珍珠层文石板片。此外,首次发现在淡水养殖珍珠的棱柱层中文石纤维与板片结晶体交替出现,同时初步建立了一种新的淡水养殖珍珠的内部结构模型。