广东省菜用桑品种资源嫩芽感官品质和营养功能成分分析

通过对国家桑树种质资源华南分圃内的230个桑树品种资源嫩芽进行感官审评,筛选出口感好、风味佳的菜用桑品种资源8个,对其主要营养物质、风味物质以及桑叶总抗氧化活性进行了测定,并对主要营养和风味物质含量与总抗氧化活性的相关性进行分析.结果表明:桑嫩芽营养和风味物质含量丰富,8个菜用桑品种资源的抗坏血酸含量为20.21～25.10 mg/hg FW、类胡萝卜素含量为4.90～5.91 mg/hgFW、可溶性蛋白含量为0.40％ ～0.53％、可溶性总糖含量为0.92％～1.47％、果糖含量为0.37％ ～0.69％、蔗糖含量为0.22％～0.58％;营养风味物质含量在不同桑树品种资源间存在明显差异,其中菜桑10的抗坏血酸、类胡萝卜素、可溶性糖含量最高,而菜桑04-107的总抗氧化活性最强;各营养物质含量与总抗氧化活性表现出不同程度的正相关,其中仅可溶性蛋白与总抗氧化活性呈显著正相关.     

盐碱环境下火龙果生长过程中果实主要营养元素含量变化

在盐碱环境下,对白肉火龙果果实生长过程中氮、磷、钾、钙、镁和钠等营养元素的动态变化进行观察、测定和分析。结果表明:氮、磷、钾和镁含量的变化趋势相似,总体呈"倒N"型变化,钙含量的变化在整个生长过程中始终保持下降趋势,钠含量波动较大。在不同生长阶段,氮、磷、钾、钙、镁和钠等营养元素含量变异系数较大,从27.60%～43.52%。果实中氮、磷、钾、钙、镁和钠含量累积的峰值均出现在花后30 d,分别为682.22、83.11、993.92、55.73、107.04和11.94 mg,在花后6～15 d及26～30 d累积速率较快。该研究结果为指导盐碱环境下火龙果的高效栽培利用提供参考。     

基于表面等离子共振技术鉴定鸡补体受体2与其配体chC3 d的亲和力

鸡补体受体2(Chicken complement receptor 2, chCR2)是一种表达于鸡B淋巴细胞表面的跨膜蛋白,chCR2可以与其生理学配体鸡补体组分3 d(Chicken complement component 3 d, chC3 d)相互作用。目前评估受体与配体亲和力的方法主要有表面等离子共振技术(Surface plasmon resonance, SPR)和生物膜干涉技术(Biolayer interferometry, BLI)等。旨在利用表面等离子共振技术鉴定chCR2受体分子与其配体chC3 d分子的亲和力。成功构建了重组真核表达载体pTT5-chCR2和pTT5-chC3 d;利用HEK 293F表达系统表达了His-chCR2和His-chC3 d蛋白;利用NI柱纯化系统纯化了His-chCR2和His-chC3 d蛋白;利用表面等离子共振技术,通过分析chCR2与chC3 d结合的动力学参数得出两者之间的平衡解离常数KD为1.37μmol/L。结果表明chCR2与其配体chC3 d之间的亲和力较高。     

Review of Nutrient Management in Freshwater Polyculture

Abstract

One of the most important issues concerning fish-pond fertilization is the determination of the optimal amount of fertilizer to be applied to the pond system. Another important concern is the suitability of fish species for polyculture in order to optimize production. The dynamics of nutrients, phytoplankton, and fish is a complex subject and practitioners are often compelled to formulate solutions without detailed scientific and practical consideration. The primary objective of pond fertilization is to maintain an optimal nutrient concentration for sustained biological production. Current fertilization practices in the Asia-Pacific region include: a fixed rate of fertilization and fertilization based on water color. Individual pond ecology determines how fertilization affects pond productivity, not the pond's physical location in relation to international borders. There is no universal recipe of “maximal” fertilization rates due to pond-specific variability. There is also no clear guide in the literature with regard to many aspects of fish-food; the type of organisms consumed, mechanisms of food consumption, and the digestibility and nutritive value of plankton. The usual practice is to divide fish according to their foraging in natural habitats; feeding on phytoplankton, zooplankton, zoo benthos, or detritus. The distinction between different feeding habits is not always absolute as many species of fish may change food preference depending on the abundance of different food items. This paper reviews the nutrient (nitrogen, N and phosphorus, P) management in regard to pond fertilization; use of organic and inorganic fertilizer and the impacts on fish production; use of organic fertilizer from different organisms (pig, cow and buffalo) and their interactions with primary production and water quality; optimum N:P concentration in pond water; and individual pond factors and their influence on fish production. A significant interaction was evident with time between water quality variables such as pH and alkalinity, and other factors, including manure type and fish species composition. This was reflected in the difference between pig and cow manure treatments. A significant interaction between species composition and fish production has been demonstrated. Fish survival and biomass production was influenced by the stocking ratio of the: rohu, Labeo rohita; mrigal, Cirrhinus mrigala; and Nile tilapia, Oreochromis niloticus. The recommended nutrient level for pond fertilization based on the South Australian Research and Development Institute (SARDI) and Research Institute for Aquaculture No. 1 (RIA#1) study is 1 ppm N:0.5 ppm P. The required quantity of fertilizer varies significantly with time. However, regional research is highly recommended to optimize fish production focusing on significant climate variability, which affects both primary and secondary production.     

Comparative effects of dietary supplementation with maggot meal and soybean meal in gibel carp (Carassius auratus gibelio) and darkbarbel catfish (Pelteobagrus vachelli): growth performance and antioxidant responses

A 6‐week growth trial was conducted to investigate the effect of dietary supplementation with maggot meal (MGM) and soybean meal (SBM) on the growth performance and antioxidant responses of gibel carp (GC) and darkbarbel catfish (DC). The basal diet was formulated to contain 114 g kg⁻¹ fish meal (FM) and 200 g kg⁻¹ SBM. The basal diet was supplemented with either 280 g kg⁻¹ FM (Control), 390 g kg⁻¹ MGM or 450 g kg⁻¹ SBM to obtain three isonitrogenous (crude protein: 380 g kg⁻¹) and isocaloric (gross energy: 16 kJ g⁻¹) diets. For GC, a significant decrease in specific growth rate (SGR) was only observed in fish fed the SBM diet compared with the control (P < 0.05). Principal components analysis (PCA) of GC showed a higher similarity in antioxidant response to dietary supplementation with MGM and SBM proteins between liver and intestine, but the DC did not. The present results suggest that supplementing 390 g kg⁻¹ MGM protein to basal diet cause an enhancement of the antioxidant capacity in GC, but supplementing 390 g kg⁻¹ MGM and 450 g kg⁻¹ SBM proteins to basal diets resulted in a significant attenuation of the antioxidant capacity in DC.     

Fish assemblages in the Southern California Current: relationships with climate, 1951–2008

We examined the dominant patterns of variability in the fish fauna of the southern California Current based on a principal component (PC) analysis of the California Cooperative Oceanic Fisheries Investigations ichthyoplankton data set, 1951–2008. Eighty‐six taxa were analyzed, including all ecologically dominant fish species, both exploited and unexploited. The first three PCs accounted for 20.5, 12.4 and 6.8% of the variance of the data, respectively (total: 39.7%). Each was dominated by taxa from particular adult or larval habitats. PC 1 predominantly represented the coherent response of 24 mesopelagic taxa from 10 families and was most highly correlated with long‐term trends in midwater oxygen levels. PC 2 was dominated by six of the seven most abundant ichthyoplankton taxa in the region, predominantly California Current endemics including key pelagic species (northern anchovy, Pacific sardine and Pacific hake), rockfishes (genus Sebastes) and two midwater taxa. It was correlated primarily with sea surface temperature and exhibited a significant declining trend. PC 3 was dominated by coastal and reef‐associated fishes with predominantly southerly affinities. It was positively correlated with sea surface temperature and sea level height, a proxy for diminished flow of the California Current. The taxa dominating PCs 2 and 3 mostly spatially co‐occur as ichthyoplankton. These results suggest that fish assemblages in the California Current are predominantly influenced by environmental forcing of their ocean habitats as adults or larvae, or both.     

播期对不同水稻品种生长特性的影响

为优化南京地区最佳播期及最适品种,以水稻品种‘两优6326’、‘南粳44’为研究对象,对不同播期试验下水稻产量和生育期及产量构成因素进行了分析。结果表明：随着播期的推迟,水稻的生育进程也相应顺延,2种水稻全生育期均缩短;播期对‘南粳44’各产量构成因素无显著影响,而‘两优6326’有效穗数在不同播期处理间差异显著(sig=0.008,P<0.05);‘两优6326’的有效穗数、‘南粳44’的有效穗数及穗粒数sig值均小于0.05,均与产量呈显著性相关;‘两优6326’产量总体高于‘南粳44’。对2种品种适宜播期综合评价表明,该地区宜早种植籼稻‘两优6326’,及早熟晚粳品种‘南粳44’。     

喀斯特山区野生燕麦农艺性状的主成分与灰色关联度分析

为进一步发掘喀斯特山区野生燕麦的优异基因资源,拓宽燕麦资源的遗传基础,对采自不同喀斯特山区的80份野生燕麦进行了农艺性状进行主成分和灰色关联度分析。结果表明,主成分分析中,筛选出的特征根累积贡献率大于85%的有穗粒数因子、穗长因子、株高因子以及千粒重因子,共4个主成分;灰色关联度分析中,株高与穗长、有效穗与穗粒数、小穗与株高、穗粒重与穗粒数、千粒重与穗粒重之间相互的关联度最大,关系最为密切。     

云南松与旱冬瓜混交林林地土壤养分及细根、叶片养分特征

为了探讨云南松与旱冬瓜混交对养分的利用情况,对云南松纯林、云南松与旱冬瓜混交林分、旱冬瓜纯林3种林分类型进行了林地土壤及叶片、根系养分质量分数的测定分析.结果表明:云南松与旱冬瓜混交林地土壤表层土的有机质、有效磷、水解氮、有效钾、全氮、全磷、全钾、交换性钙、镁离子等肥力指标都比纯林高,pH值也发生了变化,介于云南松纯林...     

不同白榆家系苗期耐盐碱综合评价

为筛选耐盐碱白榆家系,以2批白榆家系苗木为材料,分析了有效的耐盐碱评价指标和指标问的相关性,用主成分分析对家系耐盐碱性做了分类.结果表明:检测指标间多存在显著相关;基于苗木有效指标平均值和最高质量浓度胁迫值的主成分分析,分别需提取2和3个主成分,说明以平均值统计,指标间的关联更紧密;以平均值和最高质量浓度胁迫值统计,白...