共查询到19条相似文献,搜索用时 93 毫秒
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生长调节剂DPC和营养物质KH_2PO_4协同作用对棉苗茎解剖结构的调控效应 总被引:2,自引:1,他引:1
在自然光照和遮荫的弱光条件下研究了DPC(助壮素)、KH2PO4(磷酸二氧钾)单独和混合浸种对棉苗茎组织解剖结构的影响,结果表明在两种光照条件下,DPC、KH2PO4对棉苗茎的组织结构都有不同程度的影响。其中以DPC+KH2PO4处理效果优于单独使用,特别是弱光条件下,此效应更明显。DPC+KH2PO4处理使棉苗茎秆粗壮,茎秆密度(单位茎高度内予物质重)增加.茎中维管组织发育好,维管束数目多,每一维管束中分化的导管数目增多;木质部、韧皮部面积大并且发育较好,因而加强了茎的生理功能;有利于培青壮苗。 相似文献
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鱼腥藻SP.595液泡化原生质球诱导条件的研究 总被引:1,自引:0,他引:1
用浓度为0.15mol/L的KNO3、KCl、K2SO4、KH2PO4、K2HPO4、NaNO3、NaCl、Na2SO4、NaH2PO4、Na2HPO4、(NH4)2SO4、MgSO4、CaC12等单盐分别配合0.1%的溶菌酶处理鱼腥藻sp.595(Anabaenasp.595)。经4h,KH2PO4、K2SO4、Na2SO4、NaH2PO4、(NH4)2SO4、MgSO4、CaC12能诱导形成原生质球,但液泡化原生质球极少,而KNO3、NaNO3、NaC1诱导形成少量液泡化原生质球。用相近浓度的双盐,即KNO3和NaC1、KNO3和(NH4)2SO4、NaC1和(NH4)2SO4分别配合0.1%的溶菌酶处理,诱导效果亦不佳。用相近浓度的三盐NaC1、KNO3和(NH4)2SO4及五种盐NaC1、KNO3、(NH4)2SO4、Na2HPO4和KH2PO4分别配合0.1%的溶菌酶处理,诱导原生质球和液泡化原生质球的效果明显提高,液泡化原生质球比例达到66.90%—79.97%。 相似文献
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通过实验生态学的方法,分别以KNO3和KH2PO4为氮源和磷源,研究青岛大扁藻(Platymonas helgolandicavar.tsingtaoensis)和牟氏角毛藻(Chaetoceros muelleri Lemmerman)单培养和共培养时的生长状况。结果显示,不同氮磷处理对两种藻的单培养和共培养都有显著影响(P<0.05)。共培养时,青岛大扁藻的最大藻密度与氮磷浓度呈正相关。氮处理时,当培养液中KNO3为110 mg/L时,取得最大值;磷处理时,青岛大扁藻的最大藻密度在KH2PO4为9 mg/L时取得最大值;而牟氏角毛藻分别在KNO3为70 mg/L和KH2PO4为5 mg/L时取得最大值。共培养时两种藻的藻密度都低于单培养。另外,无论低氮高磷还是高氮低磷都不利于两种藻获得较大的终细胞密度。 相似文献
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DPC浸种对花生幼苗根系和叶片生理功能的影响 总被引:2,自引:0,他引:2
在田间条件下,研究了DPC浸种对花生(Arachis hypogaeaL.)幼苗根系和叶片生理功能的影响。结果表明,DPC可提高花生幼苗根系中IAA和Z ZR的含量,促进根系的生长,提高根系活力;DPC可促进花生苗期叶片叶绿素的合成,提高叶绿素含量,提高苗期叶片的光合速率。在实践中,用150mg/LDPC浸种是取得花生壮苗丰产的有效措施。 相似文献
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水杨酸对水稻防卫反应酶系的系统诱导(简报) 总被引:23,自引:0,他引:23
经 10 .0 μg·ml-1水杨酸 (SA)喷雾处理后稻苗叶片中苯丙氨酸解氨酶 (PAL)、过氧化物酶 (PO)和多酚氧化酶 (PPO)活性都迅速增强 ,处理后 12~ 2 4h达到高峰。未经SA处理的叶片中PAL、PO和PPO酶活性则在处理后 4 8h达到高峰 ,且活性增加明显低于SA处理的叶片。处理和未处理叶片中木质素含量都迅速增加。这些生理指标的时序变化与SA诱导稻苗抗白叶枯病的表现基本吻合。 相似文献
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低磷和高照度光下两种不同磷效率玉米幼苗的几种光合参数变化 总被引:3,自引:0,他引:3
以完全培养液(HP,1000μmol·L^-1KH2PO4)培养15d的玉米自交系KH5(磷高效)和SD502(磷低效)幼苗转入低磷(LP,5μmol·L^-1KH2PO4)条件下培养20d后,检测叶中几种与光合作用有关参数的结果表明,低磷下两自交系玉米叶中无机磷含量、植株生物量和叶片的净光合速率(Pn)均下降,KH5的降幅小于SD502。两自交系玉米叶片以高照度光(1600μmol·m^-2·s^-1)照射1h后,叶片的PSII实际光化学效率(ФPSII)、PSII最大光化学效率(Fv/Fm)和表观光合电子传递速率(ETR)均下降,而初始荧光(F0)、非光化学猝灭(NPQ)和天线热耗散(HDR)均升高。在强光胁迫过程中,玉米幼苗叶片发生光抑制,自交系SD502在低磷下的光抑制比KH5严重。 相似文献
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Optimization of a cultural medium for bacteriocin production by Lactococcus lactis using response surface methodology. 总被引:15,自引:0,他引:15
The medium composition for bacteriocin production by Lactococcus lactis ATCC 11454 was optimized using response surface methodology. The selected six factors based on CM medium were sucrose, soybean peptone, yeast extract, KH(2)PO(4), NaCl, and MgSO(4).7H(2)O. Fractional factorial designs (FFD) and the path of steepest ascent were effective in searching for the main factors and approaching the optimum region of the response. By a 2(6-2) FFD, sucrose, soybean peptone, yeast extract, KH(2)PO(4) were found to be significant factors and had positive effects on cell growth, however, only soybean peptone and KH(2)PO(4) were shown to be the two significant factors for bacteriocin production and had negative and positive effects, respectively. The effects of the two main factors on bacteriocin production were further investigated by a central composite design and the optimum composition was found to be 1% sucrose, 0.45% soybean peptone, 1% yeast extract, 2.84% KH(2)PO(4), 0.2% NaCl, and 0.02% MgSO(4) x 7H(2)O. The optimal medium allowed bacteriocin yield to be doubled compared to CM medium. 相似文献
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目的:提高酵母产γ-氨基丁酸的能力。方法:采用单因素及正交设计实验对酵母产γ-氨基丁酸(GABA)的培养基进行优化。结果:确定最适碳源为葡萄糖,最佳氮源为蛋白胨和硫酸铵复合氮源,合适的无机盐为KH2PO4;最佳发酵培养基为3%葡萄糖,3%蛋白胨,0.3%(NH4)2SO4和0.1%KH2PO4。在此培养条件下,摇瓶发酵可以获得1.690g.L-1的GABA产量。结论:发酵培养基的优化,提高了菌株产γ-氨基丁酸的能力。 相似文献
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长吻鮠碱性磷酸酶的动力学研究 总被引:1,自引:0,他引:1
采用生化手段,从长吻鮠(Leiocassis longirostris Günther)肝中提取出碱性磷酸酶(AKP).提纯倍数为62.08倍,比活为66.43单位/mg蛋白,提取酶液经PAGE和SDS-PAGE只呈现一条区带.该酶的最适pH为10.05,7.0>pH>11.0时不稳定;最适温度为40℃,;对热不很稳定;以磷酸苯二钠为底物其Km值为1.82×10-3mol/L.Mg2+为该酶的激活剂,L-Cys、KH2PO4、DFP、ME、EDTA-Na2为抑制剂.选用KH2PO4,和DFP作抑制类型的判断,结果表明,KH2PO4,属竞争性抑制剂,其抑制常数为2.41mmol/L,DFP为非竞争性抑制剂,抑制常数为1.01mmol/L.
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The effect of the anions, phosphate and sulphate, on normal rates of excretion of potassium in dogs.
C Baylis W J O'Connor 《Quarterly journal of experimental physiology and cognate medical sciences》1976,61(4):341-350
Small doses of (NH4)2HPO4 or KH2PO4 by stomach tube caused increase in plasma PO4 and PO4 excretion. Above a threshold of 0-8 mmol. 1(-1), increase of plasma PO4 by 0-5 mmol. 1(-1) caused PO4 excretion to increase by about 35 mumol. min.-1 After KH2PO4 this relationship was not altered by the concurrent increases in plasma K and K excretion. After doses of (NH4)2SO4 or K2SO4, excretion of SO4 was similarly related to plasma SO4 and was independent of plasma K and K excretion. An effect of PO4 on K excretion was observed after doses of (NH4)2HPO4, when increased excretion of PO4 was accompanied by increased excretion of K without change in plasma K. There was also increased excretion of NH4 and a small increase in Na excretion. The changes were similar to those produced by (NH4)2SO4 [O'Connor and Summerill, 1976]. KH2PO4 and K2SO4 produced increase in plasma K and increased excretion of K not significantly different from the changes produced by KCl or KHCO3 [Baylis and O'Connor, 1976]. After KH2PO2 or K2SO4, the urinary anion was PO4 or SO4, instead of Cl and HCO3. Any effect of anions on K excretion was much less than the effect of increase in plasma K. At low rates of excretion of K, increased urinary excretion of impermeant anion can determine increased excretion of K. However, the effect of anion is small in comparison with the effect of increase in plasma K. 相似文献
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研究了不同磷浓度时渗透压对产甘油假丝酵母甘油合成与胞内磷积累的影响。结果表明,不同磷含量时,产甘油假丝酵母甘油合成越多,分泌至胞外和积累于胞内的甘油也越多,其最大甘油合成量存在一个最适渗透压。同样;在相同渗透压下,其最大甘油合成量也存在一个最适磷浓度。在相同磷含量时,渗透压增高能够促进胞内聚磷酸盐积累;当渗透压相同时,培养基中磷含量增加,胞内游离磷和聚磷酸盐均增加。在生长稳定期后期,富磷可以促进胞内游离磷和聚磷酸盐积累显著增加。经分析发现,产甘油假丝酵母胞内积累甘油与聚磷酸盐,可能对克服对数生长期细胞数量少而渗透压胁迫大的困境发挥了极其重要的作用,从而能维持其生长稳定期较高的生物量、细胞存活率和甘油产量。 相似文献
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E E Dubinina L A Sal'nikova L F Efimova P A Evarestov 《Ukrainski? biokhimicheski? zhurnal》1986,58(3):31-36
The superoxide-dismutase (EC 1.15.1.1) activity was revealed in blood plasma after its successive treatment with alcohol, chloroform and one- or two-substituted phosphate. Its value is the highest when treating plasma with KH2PO4. The boiling of the supernatant liquid obtained after addition of K2HPO4 leads to a complete loss of the activity. The treatment of plasma with KH2PO4 provides higher stability of the enzyme to thermal actions. The analysis of EPR-spectra has shown the presence of different complex compounds of copper ions in the supernatant liquid. Certain experiments with the use of aqueous solutions of CuCl2 and histidine have shown that Cu2+ inhibits the superoxide-dismutase activity in samples treated with KH2PO4 and increases it in samples treated with K2HPO4. 相似文献
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Matsuzaki H Masuyama R Uehara M Nakamura K Suzuki K 《Bioscience, biotechnology, and biochemistry》2001,65(4):928-934
We examined whether a difference in potassium dihydrogenphosphate (KH2PO4) and potassium tripolyphosphate (K5P3O10) as dietary phosphorus sources could differentially effect the nephrocalcinosis and proximal tubular function in female rats. Rats were fed on a diet containing KH2PO4 or K5P3O10, at the normal phosphorus level (normal phosphorus diet) or at a high phosphorus level (high-phosphorus diet) for 21 d. Nephrocalcinosis, as confirmed by a histological examination, was apparent in all rats fed on the high-phosphorus diet, and this condition was more severe in those rats fed on K5P3O10 than in those fed on KH2PO4. As indicators of the proximal tubular function, the N-acetyl-beta-D-glucosaminidase activity in urine and the urinary beta2-microglobulin excretion were significantly increased in those rats fed on the high-phosphorus diet containing K5P3O10. These results indicate that the intake of a high-phosphorus diet, more strongly influenced the nephrocalcinosis and proximal tubular function when K5P3O10 rather than KH2PO4 was used as the dietary phosphorus source. 相似文献