Water Technology Centre, Indian Agricultural Research Institute, New Delhi-110 012
Online published on 25 January, 2012.
Nitrate reductase activity (NR) was determined in eleven genotypes of sorghum at five stages of growth, namely seedling stage, panicle differentiation, anthesis, anthesis+10 days and anthesis + 25 days. One group of genotypes showed higher activity of the enzyme at panicle differentiation and at post anthesis. In the second group, the genotypes had higher NR activity at anthesis, while the third group consisted of genotypes which showed a continuous increase in NR activity reaching a maximum at post-anthesis.
The effect of nitrogen application on NR activity was studied in 19 genotypes given 50, 100 and 200 kg of N/ha. There was differential response of the genotypes, some showing increase in enzyme activity with increasing levels of N, others exhibiting the opposite trend. There were also genotypes which showed least enzyme activity at the highest N level.
