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。     

极度濒危植物百山祖冷杉水培繁殖

1材料与方法1．1材料试材为百山祖保护区利用日本冷杉作砧木剪接繁殖的木质化枝条,粗0．2-0．5cm,生长健壮,无病虫害,每段枝条8-12cm,留部分叶片,每枝均含顶芽。剪好的枝条放在0．5％KMnO4溶液中,消毒30min,然后用清水冲洗3遍,备用。1．2方法试验因子：培养液,清水和霍格兰营养液;植物激素,10mg／L吲哚乙酸（IAA）和10mg／I。生根粉（ABT）。     

极度濒危植物百山祖冷杉水培繁殖

[目的]研究植物外源激素（ABT和IAA）和营养液对百山祖冷杉水培生根的作用。[方法]设清水不加任何激素（CK）、清水＋10mg/L ABT、清水＋10mg／L IAA、10mg/L ABT＋霍格兰营养液、10mg/L IAA＋霍格兰营养液5个处理进行水培百山祖冷杉,观察插条生根情况,统计愈伤形成率、生根率、生根数、根长等。[结果]ABT和IAA对百山祖冷杉水培愈伤诱导和生根率、生根数有明显促进作用,两者都适合在百山祖冷杉水培繁殖中应用;外源激素处理对最长根长和平均根长无规律性影响;有无营养液处理对百山祖冷杉水培繁殖前期各项均无影响,但在出根后会影响根的生长。[结论]研究为百山祖冷衫繁育提供了新思路,有望使其迅速脱离濒危现状。     

Nutritional parameters of dorsal and ventral fillets in summer and winter from farmed yellowtail kingfish Seriola lalandi (Valenciennes, 1833)

The nutritional profile of dorsal and ventral portions of fillets from farmed yellowtail kingfish (YTK) (Seriola lalandi, Valenciennes, 1833) was assessed in winter and summer months to evaluate if there were differential distributions of proximate constituents, fatty acid composition and mineral content seasonally and through the dorso‐ventral axis. The proximate composition of YTK fillets varied between the two anatomical locations examined. In particular, a relatively large variation was observed in crude fat content, which decreased significantly from ventral to dorsal portions of the fillet and was inversely proportional to moisture and protein content. Higher crude fat content was also observed in the fish sampled in summer, compared to those sampled in winter. The omega 3/6 ratio remained constant between fillet portions but was significantly different between seasons (summer > winter). The index of nutritional quality for EPA and DHA was markedly different regarding to fillet portion and season (summer > winter, ventral > dorsal), and significant differences in the levels of potassium, phosphorus, magnesium and iron were also evident between the seasons examined. This study clearly shows differences in nutritional profiles of fillets from farmed YTK in South Australia relative to anatomical location and season. The increase in knowledge gained from this study may lead to improved farm management practices of YTK, which may extend to other commercially relevant species to enhance the production of premium farmed products.     

Heritability of larval and juvenile growth for two stocks of Manila clam Ruditapes philippinarum

The heritability of larval and juvenile growth in natural and cultured populations of the Manila clam Ruditapes philippinarum was estimated using an unbalanced nested design and an artificial fertilization technique. A total of 33 full‐sib families and 10 half‐sib families were obtained from the natural population in Shihe (Dalian, Liaoning Province in the north‐eastern part of China), whereas 11 half‐sib families and 33 full‐sib families were generated from the cultured population in Putian (Fujian Province in the south‐eastern part of China). The offspring from each family were reared under the same hatchery and nursery conditions. Results from these studies led to estimates indicating a significantly greater influence due to the dam component compared with the sire component for both natural and cultured populations, which was mainly due to maternal effect. We found that the heritability estimates obtained from the intra‐group correlation of sire half‐sib were precise and unbiased. The narrow‐sense heritabilities of shell length for the Manila clam in the natural population (NP) at larval (at the age of 9 days) and juvenile (at the age of 30 days) stages were 0.22 ± 0.11 and 0.39 ± 0.14, respectively, whereas those in the cultured population (CP) were 0.17 ± 0.09 and 0.87 ± 0.24 respectively. The heritabilities of both NP and CP at 3 days were not significantly different from zero, and were ?0.03 for NP and ?0.14 for CP. These results suggest that selection should be highly effective in Manila clam, and that selecting either a natural or a cultured population for producing faster growing larvae and juveniles should be successful. Selective breeding could thus be used to develop high‐quality seed that would facilitate the development of a shorter culture cycle and higher yields.