Effect Of Replacing Fish Meal With Blood Meal On Chemical Composition Of Supplement For Nile Tilapia (Oreochromis Niloticus)

The objective of the work was to evaluate the effect on the nutrient content of replacing fish meal (FM) with blood meal (BM) in fish supplement. Three isonitrogenous diets (35% crude protein) were formulated using FM as the main source of animal protein (BM0); 50% replacement of FM with blood meal (BM50); or 100% replacement of FM with BM (BM100). The chemical composition (ash, crude protein, crude fat and crude fibre) and amino acid composition were determined. Replacement of FM with BM did not affect the proximate composition of the diet apart from ash content which decreased with the level of substitution. Substituting fish meal with blood meal reduced the levels of methionine, lysine, isoleucine, leucine, proline, valine and increased the levels of arginine, phenylanine and alanine in the diet. Amino acid indices revealed that BM0 had more amino acids with the highest chemical scores followed by BM50 and BM100. In all the diets, methionine was the most limiting amino acid. The essential amino acid index of the diets reduced with the level of replacement of FM (0.94, 0.88 and 0.77). The study showed substitution of up to 50% FM with BM gave a useful protein diet and 100% gave almost a poor protein diet.     

Glycine max and Glycine soja are capable of cold acclimation

Soybean has been considered a cold intolerant species; based largely upon seed germination and soil emergent evaluations. This study reports a distinct acquisition of cold tolerance, in seedlings, following short acclimation periods. Diversity in cold responses was assessed in eight cultivars of Glycine max and six accessions of G. soja. All varieties of soybean significantly increased in freezing tolerance following acclimation. This study indicates soybean seedlings are indeed capable of sensing cold and acquiring cold tolerance. Germination rates after cold imbibition were negatively correlated with maturity group, but positively correlated with cold acclimation potential in G. soja. Seed fatty acid composition was varied between the species, with Glycine soja accessions containing about 2‐times more linolenic acid (18:3) than G. max. Furthermore, high levels of linoleic acid (18:2) in seeds were positively correlated with germination rates following cold imbibition in G. soja only. We suggest that domestication has not impacted the overall ability of soybean to cold acclimate at the seedling stage and that there is little variation within the domesticated species for ability to cold acclimate. Thus, this brief comparative study reduces the enthusiasm for the “wild” species as an additional source of genetic diversity for cold tolerance.     

不同腐殖酸含量基质对烟苗品质的影响

为探索腐殖酸应用于烟草漂浮育苗的前景,改进烟草漂浮育苗基质提升烟苗品质,以‘K326’为材料,研究不同腐殖酸含量对烟苗生长及生理特性的影响。结果表明:(1)基质中添加腐殖酸能影响烟苗的生长发育,主要包括烟苗的茎高、生物量及根冠比,且腐殖酸促进烟苗生长的作用随着基质中腐殖酸含量的增加呈现先促进后抑制的作用。(2)基质中添加腐殖酸对烟苗的还苗期时间影响较小,但能显著影响烟苗的移栽成活率,以30%的腐殖酸含量下烟苗的还苗期最短,且移栽后的成活率最高。(3)基质中添加腐殖酸能一定程度影响烟苗的叶绿素含量、硝酸还原酶活性、转化酶活性及根系活力的大小,且以腐殖酸含量为30%的处理烟苗生理特性各指标较适宜。综合来看,育苗基质中添加腐殖酸能影响烟苗的品质,适宜的腐殖酸含量能显著提高烟苗的整体品质,基质中最适宜的腐殖酸含量为30%。     

土壤中根皮苷和根皮素对桃幼苗的影响

以一年生桃嫁接苗为试材,在盆栽条件下研究了苹果园土壤中特征酚酸类物质——根皮苷和根皮素对桃苗生物量、根系活力、根系保护性酶活性和MDA含量的影响。结果表明,根皮苷对桃幼苗的伤害显著,与对照相比,鲜质量、干质量分别降低了16.66%和21.58%,根系活力降低了33.04%,SOD、POD活性分别降低了40.80%和31.10%,MDA含量提高了116.34%。根皮素对桃苗的影响不大。高锰酸钾处理明显缓解了根皮苷对桃苗的伤害,苹果园土壤中的根皮苷含量降低了57.80%,提高了桃苗的生物量、根系活力和保护性酶活性,降低了MDA含量。综上,老龄苹果园土壤实测含量的根皮苷(0.343mg·kg~(-1))可降低桃苗的生物量,适量的高锰酸钾能缓解根皮苷的伤害作用。     

哺乳动物Acot2基因的研究进展

酰基辅酶A硫酯酶2(Acot2)是酰基辅酶A硫酯酶(Acots)家族成员之一,其将酰基辅酶A(CoA)水解成游离脂肪酸和CoA,具有维持细胞水平的游离脂肪酸和酰基CoA(游离脂肪酸的活化形式)的潜力,在脂质代谢中发挥重要作用。本文对Acot2基因的定位、结构特征、生理功能及其调控进行综述,以期对Acot2基因的进一步探究提供参考。     

光质对番茄营养与风味品质的影响

以番茄为试验材料,在田间大棚设施条件下,选用白、蓝、黑、红、绿5种不同颜色的遮阳网,探讨不同光质对番茄营养与风味品质的影响。结果表明,在青熟期,黑色光质促进了总氮、蛋白氮以及非蛋白氮的积累。青熟期到转色期,白色光质的番茄有机酸总量较青熟期增加了4.57倍,蓝色和绿色光质提高了番茄的总糖和还原糖含量。从转色期到成熟期,番茄氨基酸含量大小表现为蓝色>绿色>黑色>红色>白色;黑色光质的番茄有机酸总量较转色期增加了27.8%;红色光质提高了番茄红素含量和Vc含量,降低了硝酸盐含量;白色、红色和绿色光质增加了番茄的总糖和还原糖含量。番茄主要风味物质(>30 μg/kg)为水杨酸甲酯、6-甲基-庚烯-2-酮、柠檬烯、反-2-己烯醛。红光使番茄水杨酸甲酯、6-甲基-庚烯-2-酮和己烯醛含量较白光增加了11.6%、20.2%和17.2%。在大田设施条件下,转色期到成熟期可以采用红色光质提高番茄果实营养品质和风味。     

刺萼龙葵种子中适宜内参基因的筛选

入侵杂草刺萼龙葵Solanum rostratum Dunal传播扩散的主要载体是种子,研究其种子休眠萌发基因的激素调控对于其防除具有重要意义,而选择合适的内参基因可以提高相关基因表达分析的准确性。本研究以赤霉素、脱落酸和水处理的刺萼龙葵种子为材料,利用geNorm、NormFinder、BestKeeper和RefFinder 4种软件对15个候选内参基因进行表达稳定性评价,并通过检测ABI5(abscisic acid-insensitive 5)的表达验证所筛选的内参基因的适用性。结果表明,对于赤霉素、脱落酸和水处理过的种子,最稳定的内参基因分别为eIF(eukaryotic initiation factor)、SAND(SAND protein family)和ACT(β-actin);对所有种子样本而言,PP2Acs(a catalytic subunit of protein phosphatase 2A)是最稳定的内参基因。研究结果将为刺萼龙葵种子休眠萌发的遗传调控研究提供重要参考。     

酸改性麦麸挂面配方的研究

为改善挂面制品的营养保健功能,研发谷物加工副产物的深加工产品,将经过超声波-酸解法改性处理后的麦麸粉添加到面粉中用于制作酸改性麦麸挂面。通过单因素试验及正交试验优化确定酸改性麦麸挂面的最优配方。结果表明,在面粉100 g的基础上,酸改性麦麸粉添加量为6%（相当于面粉质量的百分比）、水添加量为56%、食盐添加量为3.5%、食碱添加量为0.4%、羧甲基纤维素钠添加量为0.4%,此条件下制得的挂面品质良好,且外观、适口性较好。     

阿魏酸对2种野生杜鹃种子萌发的化感作用

为探究化感物质阿魏酸对马缨杜鹃和露珠杜鹃种子萌发的化感作用,本研究采用不同浓度阿魏酸分别处理马缨杜鹃和露珠杜鹃种子,利用单因素方差对其发芽率、发芽势、发芽指数和化感指数进行差异性分析.结果表明:阿魏酸显著抑制马缨杜鹃和露珠杜鹃种子的萌发,对2种杜鹃种子的抑制作用随浓度的增加而增加.阿魏酸对马缨杜鹃和露珠杜鹃种子均具有显著的化感作用,化感效应的最强浓度为1 000 μg/mL.     

植物脱落酸信号转导途径的上游信使

脱落酸(ABA)是一种重要的植物激素,调节多种植物生理过程,并在植物应答逆境胁迫的信号转导中起重要作用。结构分子生物学分析发现,PYL蛋白具有结合ABA的活性中心。在非胁迫条件下,ABA水平较低,2C型蛋白磷酸酶(PP2C)与蔗糖非酵解型蛋白激酶2(SnRK2)结合,催化其去磷酸化而抑制其活性;在胁迫条件下,ABA水平升高,促进PYL与PP2C结合而抑制其磷酸酶活性,SnRK2靠自身磷酸化激活,又催化碱性亮氨酸拉链(b ZIP)、碱性螺旋-环-螺旋(b HLH)等类型转录因子,调控下游抗性相关基因的表达,也可由SnRK2直接催化下游抗性相关蛋白磷酸化。本文概述了在ABA胁迫下,PYL,PP2C和Sn PK2作用机制的相关研究进展,并建议将PYL、PP2C和SnRK2分别称做ABA信号转导途径的直接受体、第二信使和第三信使,建立玉米中复杂的脱落酸信号上淳传递网络。