麸酸型有机复混肥对水稻产量、品质及养分利用率的影响

探索出麸酸型有机复混肥与无机肥最适宜比例,为水稻上施用麸酸型有机复混肥提供科学依据。在等量N、P2O5、K2O养分条件下,研究施用麸酸型有机复混肥与化肥不同比例配施对水稻产量、品质及养分利用率的影响。结果表明:50%麸酸有机复混肥+50%化肥水稻经济产量与生物量最高,分别较单施化肥增产3.6%与6.5%。配施麸酸有机复混肥的总氨基酸含量较单施化肥提高4.6%～19.2%,其中必需氨基酸含量提高4.5%～21.5%,同时提高了淀粉、粗蛋白含量,且氨基酸、淀粉含量均随着麸酸有机复混肥施肥比重的增加呈先增加后降低的趋势。另外,配施有机复混肥均提高了水稻氮、钾总吸收量,氮、钾养分利用率较单施化肥分别提高了7.1～9.9与6.1～22.7个百分点,说明麸酸型有机复混肥与化肥配施能获得比单施化肥处理更高或相当的稻谷产量并有效地提高水稻的品质和养分利用率。     

Resistance of Medicago truncatula to salt stress is related to glutamine synthetase activity and sodium sequestration

The response to salinity may largely vary not only among species but even cultivars or lines of the same species. Knowledge of the reasons underlying these differential responses can be critical in breeding programs to obtain lines with enhanced performance under salinity. In this work, the responses to salt stress of three Medicago truncatula lines with contrasting salt resistance, TN6.18 (sensitive), Jemalong (reference line), and TN8.20 (resistant), have been assessed by analyzing a full array of nodule parameters (water relations, carbohydrates, ion concentrations, and enzyme activities). The aim of this work was to look for the most important criteria conferring resistance to the M. truncatula‐Sinorhizobium symbiosis under salinity. The resistance of M. truncatula to salt stress was related to nodule osmotic adjustment due to both sequestration of sodium and accumulation of soluble carbohydrates and free amino acids following protein degradation, together with an adequate nitrogen metabolism due to maintaining relatively high glutamine synthetase activity (GS) and stimulation of NADH‐dependent glutamate dehydrogenase (GDH). Glutamine synthetase activity differed clearly between the three studied lines. Thus, it may have a key role in the resistance of Medicago truncatula to salt stress.     

Effect of ammonium or nitrate nutrition on photosynthesis,growth, and nitrogen assimilation in tomato plants

Nitrogen (N) is taken up by most plant species in the form of nitrate (NO ) or ammonium (NH ). Plant response to continuous NH nutrition is species‐dependent. In this study, we compare the responses of tomato (Solanum lycopersicum L. cv. Rio Grande) plants to N source (NO or NH ). To this end, early plant growth, photosynthesis, chlorophyll, carbohydrate, and N‐compound concentrations as well as the activities of main enzymes involved in N metabolism (nitrate reductase, nitrite reductase, glutamine synthetase, and glutamate dehydrogenase) were analyzed. Early plant growth was remarkably ameliorated under NH ‐ in comparison to NO ‐based nutrition. Concomitantly, photosynthetic activity, total chlorophyll, and carbohydrate concentrations were significantly increased. With increasing external NH concentration, NH accumulated mainly in roots. In addition, root protein concentration was significantly increased, reflecting high NH incorporation into organic nitrogen. Root glutamine synthetase (GS) activity was enhanced by NH for concentrations below 5 mM, whereas root glutamate dehydrogenase (GDH) activity increased in parallel to NH availability. Together with the positive effect of NH on tomato plant cv. Rio Grande growth, these results reveal that GDH could have, in addition to GS, a possible role in NH detoxification and tolerance of NH ‐based nutrition.     

Microbial mineralization of organic matter in sinking particles,bottom sediments and seawater in a coastal fish culturing area

Microbial mineralization rates in sinking particles, bottom sediments and seawater were determined in a coastal fish (red sea bream Pagrus major) culturing area to clarify the mineralization process of organic matter (OM) in the entire water column. The mineralization rates of ¹⁴C‐labelled glutamate and glucose per unit volume were highest in the sinking particles and were 131–572 and 7–49 times higher than those of the seawater and bottom sediments respectively. The turnover time of glutamate tended to be shorter than that of glucose at all three sites of the water column. Bacteria appeared to prefer amino acids to monosaccharides because amino acids could be utilized as both energy and nitrogen sources. The sedimentation rate of particulate organic carbon (POC) derived from phytoplankton accounted for 9–61% of the total POC, and it was particularly high in early summer (61% and 50% at fish cage and non‐cage stations respectively). The present study clearly shows that sinking particles serve as an important site of microbial mineralization process of OM within the water column, and that phytoplankton production was another serious cause of organic pollution of the seafloor in addition to the organic wastes directly discharged from fish farms.     

Genetic Analysis of DIA, GOT and PGI Isozyme Loci in Daucus carota L. ssp. sativas

Isozymes are useful biochemical markers in plant breeding. This paper presents the first results on the inheritance of three enzyme systems: diaphorase (DIA), glutamate oxalacetate transaminase (GOT) and phosphoglucoisomerase (PGI) from leaves of Daucus carota L. ssp. sativus and the linkage relationships among these isozyme loci, marked Dia, Got, and Pgi. Methods of extraction and electrophoresis are described. Segregation ratios indicated that the DIA system is controlled by three genes: Dia-1, Dia-2 and Dia-3, Dia-1 as invariant. Two codominant alleles and a null allele were found for Dia-2, and four codominant alleles for Dia-3-GOT isozymes are encoded by three genes; Got-1, Got-2 and Got-3. An active allele and a null allele were observed for Got-1, two codominant alleles for Got-2 and Got-3, respectively. PGI isozymes are controlled by a single gene, Pgi-1, with two codominant alleles. Altogether one invariant isozyme locus and six polymorphic loci are postulated. Test of joint segregation suggested a linkage of Dia-3 and Pgi-1. The recombination value is 0.04 ± 0.009.     

填充盾式纤维填料和无填料的UBF厌氧反应器处理味精废水的对比试验研究

本研究采用赶集允盾式纤维填料和无填两个ＵＢＦ厌氧反应器进行味精废水处理的对比试验。结果表明，在３５℃、有机负荷相同情况下，填充盾式纤维填料的ＵＢＦ瓜在的有机物去除率、甲烷产气率等工艺性能参数均优于无填料的ＵＢＦ反应器。     

The effect of different nitrogen sources on the symbiotic interaction between Sorghum bicolor and Glomus intraradices: Expression of plant and fungal genes involved in nitrogen assimilation

In the arbuscular mycorrhizal (AM) symbiosis, plants take up part of the nitrogen (N) through a mycorrhizal pathway. In this study, we assessed the effect of different N sources on the expression of genes coding for enzymes and transporters of the mycorrhizal N uptake pathway, using Sorghum bicolor and Glomus intraradices as a model. Some of the genes investigated were differentially regulated in the intraradical and in the extraradical mycelium depending on the N source. In AM roots, some fungal and plant genes were co-regulated, suggesting an interdependence of both partners in the mycorrhizal N uptake pathway. Mycorrhizal N transfer may have a preference for glycine (plant growth and N uptake stimulation).     

玉米蛋白粉部分替代鱼粉对网箱养殖异育银鲫肌肉组织氮磷保留率的影响

研究玉米蛋白粉部分替代鱼粉对异育银鲫氮磷保留率影响,以3种规格的异育银鲫(小规格为26.90 g、中规格为51.70 g、大规格为97.67 g)为试验对象,每种规格分别设置鱼粉组和玉米蛋白粉组(鱼粉组的鱼粉用量为10%和9%,用8%玉米蛋白粉等量替代鱼粉),在网箱中饲养97 d,分别于30 d、61 d和97 d采样,测定3个阶段的肌肉氮保留率、磷保留率以及肌肉和肝胰脏谷氨酸脱氢酶(GDH)活性。结果表明:小规格异育银鲫的Ⅱ、Ⅲ阶段、中规格第Ⅰ阶段和大规格第Ⅲ阶段的肌肉组织中的氮含量存在显著差异,中、大规格的其余各阶段肌肉组织的氮含量无显著差异;肌肉组织中磷的含量在小规格的第Ⅰ、Ⅱ阶段无显著差异,第Ⅲ阶段鱼粉组磷含量显著高于玉米蛋白组(P<0.05),除大规格第Ⅲ阶段,中规格和大规格的总体上玉米蛋白组的肌肉磷含量显著高于鱼粉组(P<0.05);除中规格的第Ⅰ阶段,3种规格异育银鲫在第Ⅲ阶段内总体上呈现鱼粉组肌肉氮保留率显著高于玉米蛋白粉组 (P<0.05);3种规格异育银鲫肝胰脏的GDH活性随饲养时间延长,两组无显著差异;异育银鲫肌肉组织的GDH活性,除中规格的第Ⅱ阶段和大规格的第Ⅰ阶段,其余表现为同种规格的鱼粉组和玉米组无显著差异;除第Ⅰ阶段,其它时间段玉米组的磷保留率显著低于鱼粉组的磷保留率(P<0.05)。在该试验条件下,3种规格的异育银鲫用8%的玉米蛋白粉替代等量鱼粉降低了实验鱼的肌肉氮磷保留率,谷氨酸脱氢酶活性无显著差异,对蛋白质分解代谢无显著影响。     

麸酸有机复混肥对黄瓜产质、土壤游离氨基酸和微生物碳的影响

通过大田试验,探讨施用麸酸有机复混肥与化肥配施对黄瓜产质量、土壤游离氨基酸、土壤微生物量碳等的影响.结果表明,麸酸有机复混肥与化肥配施能提高作物产质量、土壤有机质、速效氮磷钾、土壤游离氨基酸及土壤微生物量碳的含量.与单施化肥相比,黄瓜产量提高2.5％～7.9％,Vc提高4.9％～19.6％,可溶性糖提高6.7％～25....     

吸附混凝-两段SBR法工艺处理味精废水的研究

用吸附混凝-两段SBR法处理味精废水。吸附混凝试验先加入吸附剂（硅藻土或膨润土）吸附处理后投加聚丙烯酸钠（PAS）作为絮凝剂进行混凝处理，在温度40℃、pH3.0、吸附剂投加量为1.6g/L、PAS投加量为80～100mg/kg的条件下能取得较佳的效果，CODcr去除率在55%～65%，SS去除率在85%～94%之间。稳定运行的结果表明，两段SBR法CODcr去除率为94%～96%，NH4+-N去除率为82%～93%。