Improving plant NUE: From phenotype to genotype


Lack of well defined phenotype and genotype have hampered crop improvement for N use efficiency so far (Raghuram and Sharma, 2019). We ranked 21 rice varieties (Indica) based on N-responsive germination and identified early germinating, short duration varieties that were least Nresponsive and late germinating, long duration varieties that were most Nresponsive with higher yields and NUE (Sharma et al., 2018). Using 6 contrasting varieties from this ranking, we conducted complete life cycle analysis for 25 phenological parameters in the greenhouse.

Only 20 parameters were significantly N-responsive and only 6 contributed to the NUE phenotype. It constitutes germination and flowering time, shoot/root length and vegetative biomass, apart from yield. N-responsive genes associated with these traits have been identified using microarray data and are being shortlisted for validation in activation-tagged transgenic lines. This approach can be used for any crop.