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21.
唐咏 《沈阳农业大学学报》1994,(1)
利用豌豆根瘤菌(Rhizobiumleguminosarum)DNA和好气性固氮菌(Azotobactervinelandii)DNA之间的同源性,将nifD基因插入了Tn5的豌豆根瘤菌突变株来诱导在nifD基因上产生变异的A.vinelandii突变株.先将豌豆根瘤菌的固氮结构基因nifDH克隆到大肠杆菌质粒PRK290形成新的质粒PRK2509,在协助质料PRK2013的帮助下转入A.vinelandii.对于筛选出的失去固氮能力的A.vinelandii突变株进行测定,检测无细胞提取物中不同固氮酶组分的活性以及固氨酶蛋白组分的免疫性.结果表明,利用此基因转移系统查得到A.vine;andiie的nif突变株.一些突变株的体外固氨酶活性非常低,加入纯化的固氨酶的不同组分可以增加其活性.在测定的突变株中,固氨酶的两种组分仍然存在,说明Tn5插入的位点是染色体上其它与固氮酶活性有关的位点. 相似文献
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23.
Summary N2(C2H2) fixation by Ulex gallii Planchon (dwarf or autumn flowering gorse/furze) seedlings was determined following 8 months of growth (December-August) in the glasshouse in a very acid, N- and P-deficient forest soil. Application of Na2HPO4·12H2O or North African ground rock phosphate fertilizer was essential for growth, nodulation and C2H2 reduction activity. Overall, both the sodium phosphate and the rock phosphate were equally effective P sources and the maximum acetylene reduction by intact roots was measured as 4.09 and 4.69 mol C2H4g-1 fresh weight nodule h-1, respectively. Applied NH4Cl severely inhibited nodulation and restricted acetylene reduction activity but not seedling growth. The results are discussed in relation to the spread of U. gallii in the south of Ireland and its potential as a leguminous nurse crop for Sitka spruce on the very impoverished forest soils of the region. 相似文献
24.
介绍了固氮酶的结构和催化机制,并综述了近几年在农业生产中对固氮酶活性有影响的几个因素的研究进展。这些因素包括固氮菌的品种、作物的品种、土壤类型、氮肥的类型、耕作方式和氮肥的施用时期。 相似文献
25.
Following screening, selection, characterization and examination of their symbiotic N2 fixation, only two Rhizobium strains (ND-16 and TAL-1860) and four lentil genotypes (DLG-103, LC-50, LC-53 and Sehore 74-3) were found to be suited to
sodic soils. Interactions between salt-tolerant lentil genotypes and Rhizobium strains were found to be significant, and resulted in greater nodulation, N2 fixation (nitrogenase activity), total nitrogen, plant height, root length and grain yield in sodic soils under field conditions
compared to uninoculated controls. Significantly more nodulation, nitrogenase activity, glutamine synthetase (GS) and NADH-dependent
glutamate synthase (NADH-GOGAT) activities were found in normal soil as compared to the soil supplemented with 4% and 8% NaCl.
Salt stress inhibited nitrogenase, GS and NADH-GOGAT activities. However, nitrogenase activity in nodules was more sensitive
to salt stress than GS and NADH-GOGAT activities (NH4
+ assimilation). The relevance of these findings for salt-tolerant symbionts is discussed.
Received: 14 November 1997 相似文献
26.
Morphology,biomass,nitrate reductase(NR)and nitrogenase activity in Albizia chinensis(Osb.)Merr.nodules were assessed on monthly and seasonal basis for 1 year.Average NR and nitrogenase activity was higher during the rainy season,reaching a maximum in August.Thereafter,activity decreased through autumn and reached a minimum value during winter.Fresh and dry biomass of nodules increased gradually from summer to the rainy season and then started decreasing with the onset of winter as nodules began to senesce.Among four developmental stages of the nodules that correspond to their increasing age,NR and nitrogenase activity remained low in stage 1 nodules and peaked in stage 2.The activity of both enzymes further decreased with increasing age(stage 2 to stage 4).Morphological features such as shape,diameter and color varied considerably among the developmental stages.Stage 1 nodules were cream-colored,oval to heartshaped with smallest average diameter whereas at stage 2,they became bilobed to tetralobed.On the other hand,stage 3 nodules had the largest average diameter and were multilobed in structure.Stage 4 nodules that correspond to the senescing stage were dark brown to black,multilobed,flattened and hollow due to degeneration of nodular tissue. 相似文献
27.
The effect of water regimes and soil moisture stress on total nodule number, effective nodule number, nodule dry weight, nitrogenase activity and nitrogen fixation in soybean was studied. The effective nodule number, nodule weight, nitrogenase activity and nitrogen fixation increased due to increase in water regimes from 0.4 to 0.6 Cumulative Pan Evaporation (CPE). The stress during either flowering or pod filling reduced the effective nodule number, nodule weight, nitrogenase activity and nitrogen fixation. The amount of nitrogen fixed was maximum with 0.8 CPE (50.09 kg ha-1 season-1) followed by 0.6 CPE (42.08 kg ha-1 season-1) and 0.4 CPE (33.04 kg ha-1 season-1). The amount of nitrogen fixed was reduced by 17.71 % and 26.39 % due to stress during flowering and pod filling respectively compared to normal irrigation. 相似文献
28.
Gisela Höflich Undine Behrendt Wolfgang Seyfarth 《Archives of Agronomy and Soil Science》2013,59(5-6):339-358
Phyllosphären‐ und Rhizosphärenbakterien (Pseudomonas spp., Pantoea spp., Agrobacterium spp., Rhizobium spp. bzw. Stenotrophomonas spp.) stimulierten unabhängig von der Herkunft (Getreide, Mais, Gräser, Raps, Rotklee, Kiefern) das Wachstum von W.‐Weizen, Mais und Erbsen in gemäßigten Klimaten. Sie überlebten nach Sproß‐ und Wurzelinokulation bevorzugt im Rhizosphärenraum. Auch Phyllosphärenbakterien wanderten nach Sproßinokulation in die Rhizosphäre ab. In gemäßigten Klimaten sind Wachstumsstimulierungen nicht an eine Nitrogenaseaktivität der Bakterien gebunden. Phytoeffektive Bakterien bildeten meist Phytohormone, Auxine und z.T. Cytokinine, die in den bevorzugt besiedelten Seitenwurzelzonen und Wurzelspitzen das Wurzelwachstum und die Nährstoffaufnahme aus dem Boden förderten. Das wirkte sich auch positiv auf den Chlorophyllgehalt in Maisblättern aus. Mögliche Unterschiede zur Bedeutung des Besiedlungsverhaltens und mikrobieller Stoffwechselleistungen in tropischen Klimaten werden diskutiert. 相似文献
29.
夏花生覆膜对根瘤中固氮酶和叶片硝酸还原酶活性影响的研究 总被引:4,自引:0,他引:4
覆膜夏花生有利于根瘤菌的侵染和根瘤的形成,使花生早结瘤、多结瘤、早进行共生固覆;覆膜降低结荚以前的固氮酶活性,但有利于中后期固氮酶活性的提高和维持,可延缓根瘤衰老、延长根瘤固氮时间。覆膜对花生叶片硝酸还原酶活性(NRA)的影响与固氮酶活性正好相反,结荚以前较高、中后期较低。与露地相比,覆膜花生前期利用土壤和肥料氮较多,而中后期则可主要靠根瘤固氮来提供氮素营养。 相似文献
30.
兰州地区盐碱地小麦根际联合固氮菌分离及部分特性研究 总被引:28,自引:2,他引:28
结合气相色谱仪和高效液相色谱仪 ,利用乙炔还原等方法对兰州地区盐碱地小麦根际联合固氮菌进行分离和固氮酶活性、溶磷性、分泌植物激素特性研究。结果表明 :从小麦根际分离获得的 12株联合固氮菌株固氮酶活性差异较大 (C2 H4,12 4 6~ 6 5 1 6nmolh-1ml-1) ,具有较高固氮酶活性的菌株较少 (C2 H4大于 5 0 0nmolh-1ml-1的菌株只有 4株 ) ;固氮菌株中有 2株具有溶磷性 ,其溶磷强度 (P)分别为 16 30 μgml-1和 9 82 μgml-1;9株固氮菌株可分泌IAA ,但分泌IAA浓度相对较低 (1 4 0~ 15 13μgml-1) ,大于 10 μgml-1的菌株只有 2株。从菌株固氮酶活性、溶磷性和分泌植物生长素特性看 ,Pseudomonassp ChW1、Azotobactersp ChW5、Zoogloeasp ChW6、AzotobacterchroococcumChW11和Azospirillussp ChW15等在研制小麦菌肥方面具有较大的开发潜力。 相似文献