|| 要旨トップ | 目次 |||日本生態学会第59回全国大会 (2012年3月，大津) 講演要旨
一般講演（ポスター発表） P3-030J (Poster presentation)
We compared plant growth and nitrogen acquisition between nodulated (+nod) and non-nodulated (-nod) plants under low and high soil NO3 conc. along light intensities in a N2-fixing plant, Lotus japonicus. Except under the highest light condition (685μmol m-2 sec-1) and under 0.01mM NO3 conc., growth of +nod was lower than that of -nod. The possible causes for the phenomena were different among soil nitrate concentrations. Under 0.01mM NO3 conc., total nitrogen content per plant was higher in +nod compared to -nod regardless of light intensities and %Ndfa of +nod were above 70%. These results correspond to the general aspects that higher cost of carbon consumption belongs to N2-fixation prevents biomass production of +nod. Under 1mM NO3 conc., plant biomass, root biomass, plant nitrogen content and nitrate absorption were larger in -nod compare to that of +nod. Large proportion of nitrogen was acquired through nitrate absorption even in +nod. Plant nitrogen content par root biomass did not differ among +nod and -nod. Root biomass did not differ among soil NO3 conc. in +nod. Suppression on root morphogenesis due to nodulation might prevent not only nitrate absorption but also biomass production in +nod under 1mM NO3 conc.