Maintenance respiration of Oryza sativa leaves at different growth stages as influenced by nitrogen supply

Abstract

Maintenance respiration rate, R(M), irrespective of growth stages, increased with increase in nitrogen supply. The R(M) increased almost in proportion with net photosynthetic rate, P(N), and biomass production during early growth stages, while it declined after anthesis. Significant positive correlation was observed between biomass production and P(N) at all growth stages except tillering. Though R(M) was positively correlated with biomass production during early growth stages, it was negatively correlated with the rate of increase in shoot biomass after flowering, which could indicate a possibility to identify certain cultivars endowed with low maintenance expenses despite building up biomass.