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M Nĕmcová

Publications and source records attributed to M Nĕmcová.

4 recordsLinked to original sources

Comparative response of Pisum sativum nodulated with indigenous soil Rhizobium populations and/or co-inoculated with a Rhizobium leguminosarum strain. I. Acetylene-reducing, dihydrogen- and carbon dioxide-evolving activities.

No significant differences in the acetylene-reducing activity and evolution of H2 and CO2 from nodulated roots of Pisum sativum inoculated with soil Rhizobium populations from two soils with different acidities (Ruzynĕ soil 7.6; Lukavec soil 4.9) were observed. Rhizobium population from Lukavec soil formed nodules, exhibiting a higher H2 evolution. Co-inoculation with the Hup+ strain 128C30 (7 x 10(7) cells per seedling) eliminated, to some extent, the effect of soil populations on physiological activity.

Acetylene↗

Symbiotic dinitrogen fixation as affected by short-term application of nitrate to nodulated Pisum sativum L.

Effect of nitrate on the nitrogenase (C2H2-reduction) activity, growth of nodule tissue accumulation of nitrate and nitrate reductase activity in 4-weeks-old nodulated peas (Pisum sativum L.) was investigated. A relatively slow decrease of the total nitrogenase activity (mumol C2H4 per root per h), as compared with plants cultivated without nitrate, was due to both retardation of further growth of the nodule tissue and to a decrease of their specific nitrogenase activity (mumol C2H4 per gf.wt. per h). However, an absolute and pronounced decrease of both nitrogenase activities occurred only 4 or 7 d after the application of nitrate. The addition of nitrate led to its rapid accumulation in the nodule and leaf tissue with a simultaneous induction of the nitrate reductase activity. The nitrogenase activity was not completely inhibited even after a 7-d cultivation with 280 m NO3- -N in the nutrient medium and after accumulation of up to 180 ppm NO3- -Nf.wt. in the nodule tissue. The results obtained indicate that the "photosynthate deprivation" reflects competition between assimilation of nitrate and fixation of dinitrogen.

Culture Media↗