Nitrogen(N)assimilation is a wide pathway in plants because of its fundamental importance for growth and development.The transport,assimilation and recycling of nitrogen is a highly complex and regulated process,as it...Nitrogen(N)assimilation is a wide pathway in plants because of its fundamental importance for growth and development.The transport,assimilation and recycling of nitrogen is a highly complex and regulated process,as it is the mineral nutrient that is required in great abundance by the plants.Basic approach to enhance agriculture sustainability is dependent on exploration of the elite germplasm where new cultivars could perform better even under low N.To test the effect of nitrogen levels at 100 and 125 kg ha-1 on photosynthetic pigments and N assimilation in oilseed rape(B.napus L.)canola variety GSC-7 and hybrid Hyola PAC 401 were selected for comparison with new hybrid PGSH-52 in pipeline.N assimilating enzymes were assayed at vegetative,flowering and siliquing stages of crop growth to visualise the impact of N on the productivity.Nitrogen assimilating enzymes were highest at flowering stage and enhanced with increased N level.Nitrate reductase(NR)activity improved by 11.5%,nitrite reductase(NiR)by 24.2%,glutamine synthetase(GS)by 12.2%and glutamate synthase(GOGAT)by 35.2%over recommended N dose(N100)at flowering stage.Hyola PAC 401 registered maximum enzymatic activities trailed by GSC-7 at all the three stages of crop growth.Differences existed within the genotypes for photosynthetic pigments which varied with N levels.Chlorophyll a,chlorophyll b,total chlorophyll and carotenoids increased with nitrogen at 125 kg N ha^(-1)whereas chlorophyll a/b declined at three stages of crop growth.At flowering total chlorophyll and carotenoids were maximum and enhanced by 12.8%and 5%respectively with higher nitrogen level.展开更多
文摘Nitrogen(N)assimilation is a wide pathway in plants because of its fundamental importance for growth and development.The transport,assimilation and recycling of nitrogen is a highly complex and regulated process,as it is the mineral nutrient that is required in great abundance by the plants.Basic approach to enhance agriculture sustainability is dependent on exploration of the elite germplasm where new cultivars could perform better even under low N.To test the effect of nitrogen levels at 100 and 125 kg ha-1 on photosynthetic pigments and N assimilation in oilseed rape(B.napus L.)canola variety GSC-7 and hybrid Hyola PAC 401 were selected for comparison with new hybrid PGSH-52 in pipeline.N assimilating enzymes were assayed at vegetative,flowering and siliquing stages of crop growth to visualise the impact of N on the productivity.Nitrogen assimilating enzymes were highest at flowering stage and enhanced with increased N level.Nitrate reductase(NR)activity improved by 11.5%,nitrite reductase(NiR)by 24.2%,glutamine synthetase(GS)by 12.2%and glutamate synthase(GOGAT)by 35.2%over recommended N dose(N100)at flowering stage.Hyola PAC 401 registered maximum enzymatic activities trailed by GSC-7 at all the three stages of crop growth.Differences existed within the genotypes for photosynthetic pigments which varied with N levels.Chlorophyll a,chlorophyll b,total chlorophyll and carotenoids increased with nitrogen at 125 kg N ha^(-1)whereas chlorophyll a/b declined at three stages of crop growth.At flowering total chlorophyll and carotenoids were maximum and enhanced by 12.8%and 5%respectively with higher nitrogen level.
